Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (49 commits)
stop_machine: Move local variable closer to the usage site in cpu_stop_cpu_callback()
sched, wait: Use wrapper functions
sched: Remove a stale comment
ondemand: Make the iowait-is-busy time a sysfs tunable
ondemand: Solve a big performance issue by counting IOWAIT time as busy
sched: Intoduce get_cpu_iowait_time_us()
sched: Eliminate the ts->idle_lastupdate field
sched: Fold updating of the last_update_time_info into update_ts_time_stats()
sched: Update the idle statistics in get_cpu_idle_time_us()
sched: Introduce a function to update the idle statistics
sched: Add a comment to get_cpu_idle_time_us()
cpu_stop: add dummy implementation for UP
sched: Remove rq argument to the tracepoints
rcu: need barrier() in UP synchronize_sched_expedited()
sched: correctly place paranioa memory barriers in synchronize_sched_expedited()
sched: kill paranoia check in synchronize_sched_expedited()
sched: replace migration_thread with cpu_stop
stop_machine: reimplement using cpu_stop
cpu_stop: implement stop_cpu[s]()
sched: Fix select_idle_sibling() logic in select_task_rq_fair()
...
diff --git a/Documentation/RCU/torture.txt b/Documentation/RCU/torture.txt
index 0e50bc2..5d90167 100644
--- a/Documentation/RCU/torture.txt
+++ b/Documentation/RCU/torture.txt
@@ -182,16 +182,6 @@
sched_expedited-torture: Reader Pipe: 12660320201 95875 0 0 0 0 0 0 0 0 0
sched_expedited-torture: Reader Batch: 12660424885 0 0 0 0 0 0 0 0 0 0
sched_expedited-torture: Free-Block Circulation: 1090795 1090795 1090794 1090793 1090792 1090791 1090790 1090789 1090788 1090787 0
- state: -1 / 0:0 3:0 4:0
-
-As before, the first four lines are similar to those for RCU.
-The last line shows the task-migration state. The first number is
--1 if synchronize_sched_expedited() is idle, -2 if in the process of
-posting wakeups to the migration kthreads, and N when waiting on CPU N.
-Each of the colon-separated fields following the "/" is a CPU:state pair.
-Valid states are "0" for idle, "1" for waiting for quiescent state,
-"2" for passed through quiescent state, and "3" when a race with a
-CPU-hotplug event forces use of the synchronize_sched() primitive.
USAGE
diff --git a/Documentation/scheduler/sched-design-CFS.txt b/Documentation/scheduler/sched-design-CFS.txt
index 6f33593..8239ebb 100644
--- a/Documentation/scheduler/sched-design-CFS.txt
+++ b/Documentation/scheduler/sched-design-CFS.txt
@@ -211,7 +211,7 @@
desirable to first provide fair CPU time to each user on the system and then to
each task belonging to a user.
-CONFIG_GROUP_SCHED strives to achieve exactly that. It lets tasks to be
+CONFIG_CGROUP_SCHED strives to achieve exactly that. It lets tasks to be
grouped and divides CPU time fairly among such groups.
CONFIG_RT_GROUP_SCHED permits to group real-time (i.e., SCHED_FIFO and
@@ -220,38 +220,11 @@
CONFIG_FAIR_GROUP_SCHED permits to group CFS (i.e., SCHED_NORMAL and
SCHED_BATCH) tasks.
-At present, there are two (mutually exclusive) mechanisms to group tasks for
-CPU bandwidth control purposes:
-
- - Based on user id (CONFIG_USER_SCHED)
-
- With this option, tasks are grouped according to their user id.
-
- - Based on "cgroup" pseudo filesystem (CONFIG_CGROUP_SCHED)
-
- This options needs CONFIG_CGROUPS to be defined, and lets the administrator
+ These options need CONFIG_CGROUPS to be defined, and let the administrator
create arbitrary groups of tasks, using the "cgroup" pseudo filesystem. See
Documentation/cgroups/cgroups.txt for more information about this filesystem.
-Only one of these options to group tasks can be chosen and not both.
-
-When CONFIG_USER_SCHED is defined, a directory is created in sysfs for each new
-user and a "cpu_share" file is added in that directory.
-
- # cd /sys/kernel/uids
- # cat 512/cpu_share # Display user 512's CPU share
- 1024
- # echo 2048 > 512/cpu_share # Modify user 512's CPU share
- # cat 512/cpu_share # Display user 512's CPU share
- 2048
- #
-
-CPU bandwidth between two users is divided in the ratio of their CPU shares.
-For example: if you would like user "root" to get twice the bandwidth of user
-"guest," then set the cpu_share for both the users such that "root"'s cpu_share
-is twice "guest"'s cpu_share.
-
-When CONFIG_CGROUP_SCHED is defined, a "cpu.shares" file is created for each
+When CONFIG_FAIR_GROUP_SCHED is defined, a "cpu.shares" file is created for each
group created using the pseudo filesystem. See example steps below to create
task groups and modify their CPU share using the "cgroups" pseudo filesystem.
@@ -273,24 +246,3 @@
# #Launch gmplayer (or your favourite movie player)
# echo <movie_player_pid> > multimedia/tasks
-
-8. Implementation note: user namespaces
-
-User namespaces are intended to be hierarchical. But they are currently
-only partially implemented. Each of those has ramifications for CFS.
-
-First, since user namespaces are hierarchical, the /sys/kernel/uids
-presentation is inadequate. Eventually we will likely want to use sysfs
-tagging to provide private views of /sys/kernel/uids within each user
-namespace.
-
-Second, the hierarchical nature is intended to support completely
-unprivileged use of user namespaces. So if using user groups, then
-we want the users in a user namespace to be children of the user
-who created it.
-
-That is currently unimplemented. So instead, every user in a new
-user namespace will receive 1024 shares just like any user in the
-initial user namespace. Note that at the moment creation of a new
-user namespace requires each of CAP_SYS_ADMIN, CAP_SETUID, and
-CAP_SETGID.
diff --git a/Documentation/scheduler/sched-rt-group.txt b/Documentation/scheduler/sched-rt-group.txt
index 86eabe6..605b0d4 100644
--- a/Documentation/scheduler/sched-rt-group.txt
+++ b/Documentation/scheduler/sched-rt-group.txt
@@ -126,23 +126,12 @@
2.3 Basis for grouping tasks
----------------------------
-There are two compile-time settings for allocating CPU bandwidth. These are
-configured using the "Basis for grouping tasks" multiple choice menu under
-General setup > Group CPU Scheduler:
-
-a. CONFIG_USER_SCHED (aka "Basis for grouping tasks" = "user id")
-
-This lets you use the virtual files under
-"/sys/kernel/uids/<uid>/cpu_rt_runtime_us" to control he CPU time reserved for
-each user .
-
-The other option is:
-
-.o CONFIG_CGROUP_SCHED (aka "Basis for grouping tasks" = "Control groups")
+Enabling CONFIG_RT_GROUP_SCHED lets you explicitly allocate real
+CPU bandwidth to task groups.
This uses the /cgroup virtual file system and
"/cgroup/<cgroup>/cpu.rt_runtime_us" to control the CPU time reserved for each
-control group instead.
+control group.
For more information on working with control groups, you should read
Documentation/cgroups/cgroups.txt as well.
@@ -161,8 +150,7 @@
===============
There is work in progress to make the scheduling period for each group
-("/sys/kernel/uids/<uid>/cpu_rt_period_us" or
-"/cgroup/<cgroup>/cpu.rt_period_us" respectively) configurable as well.
+("/cgroup/<cgroup>/cpu.rt_period_us") configurable as well.
The constraint on the period is that a subgroup must have a smaller or
equal period to its parent. But realistically its not very useful _yet_
diff --git a/arch/s390/kernel/time.c b/arch/s390/kernel/time.c
index d906bf1..a2163c9 100644
--- a/arch/s390/kernel/time.c
+++ b/arch/s390/kernel/time.c
@@ -391,7 +391,6 @@
if (time_sync_wq)
return;
time_sync_wq = create_singlethread_workqueue("timesync");
- stop_machine_create();
}
/*
diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c
index bd444dc..8e9dbdc 100644
--- a/drivers/cpufreq/cpufreq_ondemand.c
+++ b/drivers/cpufreq/cpufreq_ondemand.c
@@ -73,6 +73,7 @@
struct cpu_dbs_info_s {
cputime64_t prev_cpu_idle;
+ cputime64_t prev_cpu_iowait;
cputime64_t prev_cpu_wall;
cputime64_t prev_cpu_nice;
struct cpufreq_policy *cur_policy;
@@ -108,6 +109,7 @@
unsigned int down_differential;
unsigned int ignore_nice;
unsigned int powersave_bias;
+ unsigned int io_is_busy;
} dbs_tuners_ins = {
.up_threshold = DEF_FREQUENCY_UP_THRESHOLD,
.down_differential = DEF_FREQUENCY_DOWN_DIFFERENTIAL,
@@ -148,6 +150,16 @@
return idle_time;
}
+static inline cputime64_t get_cpu_iowait_time(unsigned int cpu, cputime64_t *wall)
+{
+ u64 iowait_time = get_cpu_iowait_time_us(cpu, wall);
+
+ if (iowait_time == -1ULL)
+ return 0;
+
+ return iowait_time;
+}
+
/*
* Find right freq to be set now with powersave_bias on.
* Returns the freq_hi to be used right now and will set freq_hi_jiffies,
@@ -249,6 +261,7 @@
return sprintf(buf, "%u\n", dbs_tuners_ins.object); \
}
show_one(sampling_rate, sampling_rate);
+show_one(io_is_busy, io_is_busy);
show_one(up_threshold, up_threshold);
show_one(ignore_nice_load, ignore_nice);
show_one(powersave_bias, powersave_bias);
@@ -299,6 +312,23 @@
return count;
}
+static ssize_t store_io_is_busy(struct kobject *a, struct attribute *b,
+ const char *buf, size_t count)
+{
+ unsigned int input;
+ int ret;
+
+ ret = sscanf(buf, "%u", &input);
+ if (ret != 1)
+ return -EINVAL;
+
+ mutex_lock(&dbs_mutex);
+ dbs_tuners_ins.io_is_busy = !!input;
+ mutex_unlock(&dbs_mutex);
+
+ return count;
+}
+
static ssize_t store_up_threshold(struct kobject *a, struct attribute *b,
const char *buf, size_t count)
{
@@ -381,6 +411,7 @@
__ATTR(_name, 0644, show_##_name, store_##_name)
define_one_rw(sampling_rate);
+define_one_rw(io_is_busy);
define_one_rw(up_threshold);
define_one_rw(ignore_nice_load);
define_one_rw(powersave_bias);
@@ -392,6 +423,7 @@
&up_threshold.attr,
&ignore_nice_load.attr,
&powersave_bias.attr,
+ &io_is_busy.attr,
NULL
};
@@ -470,14 +502,15 @@
for_each_cpu(j, policy->cpus) {
struct cpu_dbs_info_s *j_dbs_info;
- cputime64_t cur_wall_time, cur_idle_time;
- unsigned int idle_time, wall_time;
+ cputime64_t cur_wall_time, cur_idle_time, cur_iowait_time;
+ unsigned int idle_time, wall_time, iowait_time;
unsigned int load, load_freq;
int freq_avg;
j_dbs_info = &per_cpu(od_cpu_dbs_info, j);
cur_idle_time = get_cpu_idle_time(j, &cur_wall_time);
+ cur_iowait_time = get_cpu_iowait_time(j, &cur_wall_time);
wall_time = (unsigned int) cputime64_sub(cur_wall_time,
j_dbs_info->prev_cpu_wall);
@@ -487,6 +520,10 @@
j_dbs_info->prev_cpu_idle);
j_dbs_info->prev_cpu_idle = cur_idle_time;
+ iowait_time = (unsigned int) cputime64_sub(cur_iowait_time,
+ j_dbs_info->prev_cpu_iowait);
+ j_dbs_info->prev_cpu_iowait = cur_iowait_time;
+
if (dbs_tuners_ins.ignore_nice) {
cputime64_t cur_nice;
unsigned long cur_nice_jiffies;
@@ -504,6 +541,16 @@
idle_time += jiffies_to_usecs(cur_nice_jiffies);
}
+ /*
+ * For the purpose of ondemand, waiting for disk IO is an
+ * indication that you're performance critical, and not that
+ * the system is actually idle. So subtract the iowait time
+ * from the cpu idle time.
+ */
+
+ if (dbs_tuners_ins.io_is_busy && idle_time >= iowait_time)
+ idle_time -= iowait_time;
+
if (unlikely(!wall_time || wall_time < idle_time))
continue;
@@ -617,6 +664,29 @@
cancel_delayed_work_sync(&dbs_info->work);
}
+/*
+ * Not all CPUs want IO time to be accounted as busy; this dependson how
+ * efficient idling at a higher frequency/voltage is.
+ * Pavel Machek says this is not so for various generations of AMD and old
+ * Intel systems.
+ * Mike Chan (androidlcom) calis this is also not true for ARM.
+ * Because of this, whitelist specific known (series) of CPUs by default, and
+ * leave all others up to the user.
+ */
+static int should_io_be_busy(void)
+{
+#if defined(CONFIG_X86)
+ /*
+ * For Intel, Core 2 (model 15) andl later have an efficient idle.
+ */
+ if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
+ boot_cpu_data.x86 == 6 &&
+ boot_cpu_data.x86_model >= 15)
+ return 1;
+#endif
+ return 0;
+}
+
static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
unsigned int event)
{
@@ -679,6 +749,7 @@
dbs_tuners_ins.sampling_rate =
max(min_sampling_rate,
latency * LATENCY_MULTIPLIER);
+ dbs_tuners_ins.io_is_busy = should_io_be_busy();
}
mutex_unlock(&dbs_mutex);
diff --git a/drivers/xen/manage.c b/drivers/xen/manage.c
index 2ac4440..8943b8c 100644
--- a/drivers/xen/manage.c
+++ b/drivers/xen/manage.c
@@ -80,12 +80,6 @@
shutting_down = SHUTDOWN_SUSPEND;
- err = stop_machine_create();
- if (err) {
- printk(KERN_ERR "xen suspend: failed to setup stop_machine %d\n", err);
- goto out;
- }
-
#ifdef CONFIG_PREEMPT
/* If the kernel is preemptible, we need to freeze all the processes
to prevent them from being in the middle of a pagetable update
@@ -93,7 +87,7 @@
err = freeze_processes();
if (err) {
printk(KERN_ERR "xen suspend: freeze failed %d\n", err);
- goto out_destroy_sm;
+ goto out;
}
#endif
@@ -136,12 +130,8 @@
out_thaw:
#ifdef CONFIG_PREEMPT
thaw_processes();
-
-out_destroy_sm:
-#endif
- stop_machine_destroy();
-
out:
+#endif
shutting_down = SHUTDOWN_INVALID;
}
#endif /* CONFIG_PM_SLEEP */
diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index bd056a5..3817149 100644
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -1140,8 +1140,7 @@
* ep_poll_callback() when events will become available.
*/
init_waitqueue_entry(&wait, current);
- wait.flags |= WQ_FLAG_EXCLUSIVE;
- __add_wait_queue(&ep->wq, &wait);
+ __add_wait_queue_exclusive(&ep->wq, &wait);
for (;;) {
/*
diff --git a/include/linux/cpuset.h b/include/linux/cpuset.h
index a5740fc..a73454a 100644
--- a/include/linux/cpuset.h
+++ b/include/linux/cpuset.h
@@ -21,8 +21,7 @@
extern int cpuset_init(void);
extern void cpuset_init_smp(void);
extern void cpuset_cpus_allowed(struct task_struct *p, struct cpumask *mask);
-extern void cpuset_cpus_allowed_locked(struct task_struct *p,
- struct cpumask *mask);
+extern int cpuset_cpus_allowed_fallback(struct task_struct *p);
extern nodemask_t cpuset_mems_allowed(struct task_struct *p);
#define cpuset_current_mems_allowed (current->mems_allowed)
void cpuset_init_current_mems_allowed(void);
@@ -69,9 +68,6 @@
extern void cpuset_task_status_allowed(struct seq_file *m,
struct task_struct *task);
-extern void cpuset_lock(void);
-extern void cpuset_unlock(void);
-
extern int cpuset_mem_spread_node(void);
static inline int cpuset_do_page_mem_spread(void)
@@ -105,10 +101,11 @@
{
cpumask_copy(mask, cpu_possible_mask);
}
-static inline void cpuset_cpus_allowed_locked(struct task_struct *p,
- struct cpumask *mask)
+
+static inline int cpuset_cpus_allowed_fallback(struct task_struct *p)
{
- cpumask_copy(mask, cpu_possible_mask);
+ cpumask_copy(&p->cpus_allowed, cpu_possible_mask);
+ return cpumask_any(cpu_active_mask);
}
static inline nodemask_t cpuset_mems_allowed(struct task_struct *p)
@@ -157,9 +154,6 @@
{
}
-static inline void cpuset_lock(void) {}
-static inline void cpuset_unlock(void) {}
-
static inline int cpuset_mem_spread_node(void)
{
return 0;
diff --git a/include/linux/rcutiny.h b/include/linux/rcutiny.h
index 14e5a76..e2e8931 100644
--- a/include/linux/rcutiny.h
+++ b/include/linux/rcutiny.h
@@ -64,8 +64,6 @@
return 0;
}
-extern int rcu_expedited_torture_stats(char *page);
-
static inline void rcu_force_quiescent_state(void)
{
}
diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h
index 4828205..c0ed1c0 100644
--- a/include/linux/rcutree.h
+++ b/include/linux/rcutree.h
@@ -36,7 +36,6 @@
extern void rcu_bh_qs(int cpu);
extern void rcu_note_context_switch(int cpu);
extern int rcu_needs_cpu(int cpu);
-extern int rcu_expedited_torture_stats(char *page);
#ifdef CONFIG_TREE_PREEMPT_RCU
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 28b71ee..b55e988 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -274,11 +274,17 @@
#if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ)
extern int select_nohz_load_balancer(int cpu);
extern int get_nohz_load_balancer(void);
+extern int nohz_ratelimit(int cpu);
#else
static inline int select_nohz_load_balancer(int cpu)
{
return 0;
}
+
+static inline int nohz_ratelimit(int cpu)
+{
+ return 0;
+}
#endif
/*
@@ -953,6 +959,7 @@
char *name;
#endif
+ unsigned int span_weight;
/*
* Span of all CPUs in this domain.
*
@@ -1025,12 +1032,17 @@
#define WF_SYNC 0x01 /* waker goes to sleep after wakup */
#define WF_FORK 0x02 /* child wakeup after fork */
+#define ENQUEUE_WAKEUP 1
+#define ENQUEUE_WAKING 2
+#define ENQUEUE_HEAD 4
+
+#define DEQUEUE_SLEEP 1
+
struct sched_class {
const struct sched_class *next;
- void (*enqueue_task) (struct rq *rq, struct task_struct *p, int wakeup,
- bool head);
- void (*dequeue_task) (struct rq *rq, struct task_struct *p, int sleep);
+ void (*enqueue_task) (struct rq *rq, struct task_struct *p, int flags);
+ void (*dequeue_task) (struct rq *rq, struct task_struct *p, int flags);
void (*yield_task) (struct rq *rq);
void (*check_preempt_curr) (struct rq *rq, struct task_struct *p, int flags);
@@ -1039,7 +1051,8 @@
void (*put_prev_task) (struct rq *rq, struct task_struct *p);
#ifdef CONFIG_SMP
- int (*select_task_rq)(struct task_struct *p, int sd_flag, int flags);
+ int (*select_task_rq)(struct rq *rq, struct task_struct *p,
+ int sd_flag, int flags);
void (*pre_schedule) (struct rq *this_rq, struct task_struct *task);
void (*post_schedule) (struct rq *this_rq);
@@ -1076,36 +1089,8 @@
unsigned long weight, inv_weight;
};
-/*
- * CFS stats for a schedulable entity (task, task-group etc)
- *
- * Current field usage histogram:
- *
- * 4 se->block_start
- * 4 se->run_node
- * 4 se->sleep_start
- * 6 se->load.weight
- */
-struct sched_entity {
- struct load_weight load; /* for load-balancing */
- struct rb_node run_node;
- struct list_head group_node;
- unsigned int on_rq;
-
- u64 exec_start;
- u64 sum_exec_runtime;
- u64 vruntime;
- u64 prev_sum_exec_runtime;
-
- u64 last_wakeup;
- u64 avg_overlap;
-
- u64 nr_migrations;
-
- u64 start_runtime;
- u64 avg_wakeup;
-
#ifdef CONFIG_SCHEDSTATS
+struct sched_statistics {
u64 wait_start;
u64 wait_max;
u64 wait_count;
@@ -1137,6 +1122,24 @@
u64 nr_wakeups_affine_attempts;
u64 nr_wakeups_passive;
u64 nr_wakeups_idle;
+};
+#endif
+
+struct sched_entity {
+ struct load_weight load; /* for load-balancing */
+ struct rb_node run_node;
+ struct list_head group_node;
+ unsigned int on_rq;
+
+ u64 exec_start;
+ u64 sum_exec_runtime;
+ u64 vruntime;
+ u64 prev_sum_exec_runtime;
+
+ u64 nr_migrations;
+
+#ifdef CONFIG_SCHEDSTATS
+ struct sched_statistics statistics;
#endif
#ifdef CONFIG_FAIR_GROUP_SCHED
@@ -1839,6 +1842,7 @@
extern void sched_clock_idle_wakeup_event(u64 delta_ns);
#ifdef CONFIG_HOTPLUG_CPU
+extern void move_task_off_dead_cpu(int dead_cpu, struct task_struct *p);
extern void idle_task_exit(void);
#else
static inline void idle_task_exit(void) {}
diff --git a/include/linux/stop_machine.h b/include/linux/stop_machine.h
index baba3a2..6b524a0 100644
--- a/include/linux/stop_machine.h
+++ b/include/linux/stop_machine.h
@@ -1,13 +1,101 @@
#ifndef _LINUX_STOP_MACHINE
#define _LINUX_STOP_MACHINE
-/* "Bogolock": stop the entire machine, disable interrupts. This is a
- very heavy lock, which is equivalent to grabbing every spinlock
- (and more). So the "read" side to such a lock is anything which
- disables preeempt. */
+
#include <linux/cpu.h>
#include <linux/cpumask.h>
+#include <linux/list.h>
#include <asm/system.h>
+/*
+ * stop_cpu[s]() is simplistic per-cpu maximum priority cpu
+ * monopolization mechanism. The caller can specify a non-sleeping
+ * function to be executed on a single or multiple cpus preempting all
+ * other processes and monopolizing those cpus until it finishes.
+ *
+ * Resources for this mechanism are preallocated when a cpu is brought
+ * up and requests are guaranteed to be served as long as the target
+ * cpus are online.
+ */
+typedef int (*cpu_stop_fn_t)(void *arg);
+
+#ifdef CONFIG_SMP
+
+struct cpu_stop_work {
+ struct list_head list; /* cpu_stopper->works */
+ cpu_stop_fn_t fn;
+ void *arg;
+ struct cpu_stop_done *done;
+};
+
+int stop_one_cpu(unsigned int cpu, cpu_stop_fn_t fn, void *arg);
+void stop_one_cpu_nowait(unsigned int cpu, cpu_stop_fn_t fn, void *arg,
+ struct cpu_stop_work *work_buf);
+int stop_cpus(const struct cpumask *cpumask, cpu_stop_fn_t fn, void *arg);
+int try_stop_cpus(const struct cpumask *cpumask, cpu_stop_fn_t fn, void *arg);
+
+#else /* CONFIG_SMP */
+
+#include <linux/workqueue.h>
+
+struct cpu_stop_work {
+ struct work_struct work;
+ cpu_stop_fn_t fn;
+ void *arg;
+};
+
+static inline int stop_one_cpu(unsigned int cpu, cpu_stop_fn_t fn, void *arg)
+{
+ int ret = -ENOENT;
+ preempt_disable();
+ if (cpu == smp_processor_id())
+ ret = fn(arg);
+ preempt_enable();
+ return ret;
+}
+
+static void stop_one_cpu_nowait_workfn(struct work_struct *work)
+{
+ struct cpu_stop_work *stwork =
+ container_of(work, struct cpu_stop_work, work);
+ preempt_disable();
+ stwork->fn(stwork->arg);
+ preempt_enable();
+}
+
+static inline void stop_one_cpu_nowait(unsigned int cpu,
+ cpu_stop_fn_t fn, void *arg,
+ struct cpu_stop_work *work_buf)
+{
+ if (cpu == smp_processor_id()) {
+ INIT_WORK(&work_buf->work, stop_one_cpu_nowait_workfn);
+ work_buf->fn = fn;
+ work_buf->arg = arg;
+ schedule_work(&work_buf->work);
+ }
+}
+
+static inline int stop_cpus(const struct cpumask *cpumask,
+ cpu_stop_fn_t fn, void *arg)
+{
+ if (cpumask_test_cpu(raw_smp_processor_id(), cpumask))
+ return stop_one_cpu(raw_smp_processor_id(), fn, arg);
+ return -ENOENT;
+}
+
+static inline int try_stop_cpus(const struct cpumask *cpumask,
+ cpu_stop_fn_t fn, void *arg)
+{
+ return stop_cpus(cpumask, fn, arg);
+}
+
+#endif /* CONFIG_SMP */
+
+/*
+ * stop_machine "Bogolock": stop the entire machine, disable
+ * interrupts. This is a very heavy lock, which is equivalent to
+ * grabbing every spinlock (and more). So the "read" side to such a
+ * lock is anything which disables preeempt.
+ */
#if defined(CONFIG_STOP_MACHINE) && defined(CONFIG_SMP)
/**
@@ -36,24 +124,7 @@
*/
int __stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus);
-/**
- * stop_machine_create: create all stop_machine threads
- *
- * Description: This causes all stop_machine threads to be created before
- * stop_machine actually gets called. This can be used by subsystems that
- * need a non failing stop_machine infrastructure.
- */
-int stop_machine_create(void);
-
-/**
- * stop_machine_destroy: destroy all stop_machine threads
- *
- * Description: This causes all stop_machine threads which were created with
- * stop_machine_create to be destroyed again.
- */
-void stop_machine_destroy(void);
-
-#else
+#else /* CONFIG_STOP_MACHINE && CONFIG_SMP */
static inline int stop_machine(int (*fn)(void *), void *data,
const struct cpumask *cpus)
@@ -65,8 +136,5 @@
return ret;
}
-static inline int stop_machine_create(void) { return 0; }
-static inline void stop_machine_destroy(void) { }
-
-#endif /* CONFIG_SMP */
-#endif /* _LINUX_STOP_MACHINE */
+#endif /* CONFIG_STOP_MACHINE && CONFIG_SMP */
+#endif /* _LINUX_STOP_MACHINE */
diff --git a/include/linux/tick.h b/include/linux/tick.h
index d2ae79e..b232ccc 100644
--- a/include/linux/tick.h
+++ b/include/linux/tick.h
@@ -42,6 +42,7 @@
* @idle_waketime: Time when the idle was interrupted
* @idle_exittime: Time when the idle state was left
* @idle_sleeptime: Sum of the time slept in idle with sched tick stopped
+ * @iowait_sleeptime: Sum of the time slept in idle with sched tick stopped, with IO outstanding
* @sleep_length: Duration of the current idle sleep
* @do_timer_lst: CPU was the last one doing do_timer before going idle
*/
@@ -60,7 +61,7 @@
ktime_t idle_waketime;
ktime_t idle_exittime;
ktime_t idle_sleeptime;
- ktime_t idle_lastupdate;
+ ktime_t iowait_sleeptime;
ktime_t sleep_length;
unsigned long last_jiffies;
unsigned long next_jiffies;
@@ -124,6 +125,7 @@
extern void tick_nohz_restart_sched_tick(void);
extern ktime_t tick_nohz_get_sleep_length(void);
extern u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time);
+extern u64 get_cpu_iowait_time_us(int cpu, u64 *last_update_time);
# else
static inline void tick_nohz_stop_sched_tick(int inidle) { }
static inline void tick_nohz_restart_sched_tick(void) { }
@@ -134,6 +136,7 @@
return len;
}
static inline u64 get_cpu_idle_time_us(int cpu, u64 *unused) { return -1; }
+static inline u64 get_cpu_iowait_time_us(int cpu, u64 *unused) { return -1; }
# endif /* !NO_HZ */
#endif
diff --git a/include/linux/wait.h b/include/linux/wait.h
index a48e16b..76d96d0 100644
--- a/include/linux/wait.h
+++ b/include/linux/wait.h
@@ -127,12 +127,26 @@
/*
* Used for wake-one threads:
*/
+static inline void __add_wait_queue_exclusive(wait_queue_head_t *q,
+ wait_queue_t *wait)
+{
+ wait->flags |= WQ_FLAG_EXCLUSIVE;
+ __add_wait_queue(q, wait);
+}
+
static inline void __add_wait_queue_tail(wait_queue_head_t *head,
- wait_queue_t *new)
+ wait_queue_t *new)
{
list_add_tail(&new->task_list, &head->task_list);
}
+static inline void __add_wait_queue_tail_exclusive(wait_queue_head_t *q,
+ wait_queue_t *wait)
+{
+ wait->flags |= WQ_FLAG_EXCLUSIVE;
+ __add_wait_queue_tail(q, wait);
+}
+
static inline void __remove_wait_queue(wait_queue_head_t *head,
wait_queue_t *old)
{
@@ -404,25 +418,6 @@
})
/*
- * Must be called with the spinlock in the wait_queue_head_t held.
- */
-static inline void add_wait_queue_exclusive_locked(wait_queue_head_t *q,
- wait_queue_t * wait)
-{
- wait->flags |= WQ_FLAG_EXCLUSIVE;
- __add_wait_queue_tail(q, wait);
-}
-
-/*
- * Must be called with the spinlock in the wait_queue_head_t held.
- */
-static inline void remove_wait_queue_locked(wait_queue_head_t *q,
- wait_queue_t * wait)
-{
- __remove_wait_queue(q, wait);
-}
-
-/*
* These are the old interfaces to sleep waiting for an event.
* They are racy. DO NOT use them, use the wait_event* interfaces above.
* We plan to remove these interfaces.
diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h
index cfceb0b..4f733ec 100644
--- a/include/trace/events/sched.h
+++ b/include/trace/events/sched.h
@@ -51,15 +51,12 @@
/*
* Tracepoint for waiting on task to unschedule:
- *
- * (NOTE: the 'rq' argument is not used by generic trace events,
- * but used by the latency tracer plugin. )
*/
TRACE_EVENT(sched_wait_task,
- TP_PROTO(struct rq *rq, struct task_struct *p),
+ TP_PROTO(struct task_struct *p),
- TP_ARGS(rq, p),
+ TP_ARGS(p),
TP_STRUCT__entry(
__array( char, comm, TASK_COMM_LEN )
@@ -79,15 +76,12 @@
/*
* Tracepoint for waking up a task:
- *
- * (NOTE: the 'rq' argument is not used by generic trace events,
- * but used by the latency tracer plugin. )
*/
DECLARE_EVENT_CLASS(sched_wakeup_template,
- TP_PROTO(struct rq *rq, struct task_struct *p, int success),
+ TP_PROTO(struct task_struct *p, int success),
- TP_ARGS(rq, p, success),
+ TP_ARGS(p, success),
TP_STRUCT__entry(
__array( char, comm, TASK_COMM_LEN )
@@ -111,31 +105,25 @@
);
DEFINE_EVENT(sched_wakeup_template, sched_wakeup,
- TP_PROTO(struct rq *rq, struct task_struct *p, int success),
- TP_ARGS(rq, p, success));
+ TP_PROTO(struct task_struct *p, int success),
+ TP_ARGS(p, success));
/*
* Tracepoint for waking up a new task:
- *
- * (NOTE: the 'rq' argument is not used by generic trace events,
- * but used by the latency tracer plugin. )
*/
DEFINE_EVENT(sched_wakeup_template, sched_wakeup_new,
- TP_PROTO(struct rq *rq, struct task_struct *p, int success),
- TP_ARGS(rq, p, success));
+ TP_PROTO(struct task_struct *p, int success),
+ TP_ARGS(p, success));
/*
* Tracepoint for task switches, performed by the scheduler:
- *
- * (NOTE: the 'rq' argument is not used by generic trace events,
- * but used by the latency tracer plugin. )
*/
TRACE_EVENT(sched_switch,
- TP_PROTO(struct rq *rq, struct task_struct *prev,
+ TP_PROTO(struct task_struct *prev,
struct task_struct *next),
- TP_ARGS(rq, prev, next),
+ TP_ARGS(prev, next),
TP_STRUCT__entry(
__array( char, prev_comm, TASK_COMM_LEN )
diff --git a/init/Kconfig b/init/Kconfig
index eb77e8c..5fe94b8 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -604,8 +604,7 @@
default n
help
This feature lets you explicitly allocate real CPU bandwidth
- to users or control groups (depending on the "Basis for grouping tasks"
- setting below. If enabled, it will also make it impossible to
+ to task groups. If enabled, it will also make it impossible to
schedule realtime tasks for non-root users until you allocate
realtime bandwidth for them.
See Documentation/scheduler/sched-rt-group.txt for more information.
diff --git a/kernel/Makefile b/kernel/Makefile
index a987aa1..149e18e 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -68,7 +68,7 @@
obj-$(CONFIG_PID_NS) += pid_namespace.o
obj-$(CONFIG_IKCONFIG) += configs.o
obj-$(CONFIG_RESOURCE_COUNTERS) += res_counter.o
-obj-$(CONFIG_STOP_MACHINE) += stop_machine.o
+obj-$(CONFIG_SMP) += stop_machine.o
obj-$(CONFIG_KPROBES_SANITY_TEST) += test_kprobes.o
obj-$(CONFIG_AUDIT) += audit.o auditfilter.o audit_watch.o
obj-$(CONFIG_AUDITSYSCALL) += auditsc.o
diff --git a/kernel/capability.c b/kernel/capability.c
index 9e4697e..2f05303 100644
--- a/kernel/capability.c
+++ b/kernel/capability.c
@@ -15,7 +15,6 @@
#include <linux/syscalls.h>
#include <linux/pid_namespace.h>
#include <asm/uaccess.h>
-#include "cred-internals.h"
/*
* Leveraged for setting/resetting capabilities
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 6d870f2..e9ec642 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -3016,7 +3016,7 @@
unsigned long flags = (unsigned long)key;
if (flags & POLLHUP) {
- remove_wait_queue_locked(event->wqh, &event->wait);
+ __remove_wait_queue(event->wqh, &event->wait);
spin_lock(&cgrp->event_list_lock);
list_del(&event->list);
spin_unlock(&cgrp->event_list_lock);
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 25bba73..5457775 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -164,6 +164,7 @@
}
struct take_cpu_down_param {
+ struct task_struct *caller;
unsigned long mod;
void *hcpu;
};
@@ -172,6 +173,7 @@
static int __ref take_cpu_down(void *_param)
{
struct take_cpu_down_param *param = _param;
+ unsigned int cpu = (unsigned long)param->hcpu;
int err;
/* Ensure this CPU doesn't handle any more interrupts. */
@@ -182,6 +184,8 @@
raw_notifier_call_chain(&cpu_chain, CPU_DYING | param->mod,
param->hcpu);
+ if (task_cpu(param->caller) == cpu)
+ move_task_off_dead_cpu(cpu, param->caller);
/* Force idle task to run as soon as we yield: it should
immediately notice cpu is offline and die quickly. */
sched_idle_next();
@@ -192,10 +196,10 @@
static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
{
int err, nr_calls = 0;
- cpumask_var_t old_allowed;
void *hcpu = (void *)(long)cpu;
unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0;
struct take_cpu_down_param tcd_param = {
+ .caller = current,
.mod = mod,
.hcpu = hcpu,
};
@@ -206,9 +210,6 @@
if (!cpu_online(cpu))
return -EINVAL;
- if (!alloc_cpumask_var(&old_allowed, GFP_KERNEL))
- return -ENOMEM;
-
cpu_hotplug_begin();
set_cpu_active(cpu, false);
err = __raw_notifier_call_chain(&cpu_chain, CPU_DOWN_PREPARE | mod,
@@ -225,10 +226,6 @@
goto out_release;
}
- /* Ensure that we are not runnable on dying cpu */
- cpumask_copy(old_allowed, ¤t->cpus_allowed);
- set_cpus_allowed_ptr(current, cpu_active_mask);
-
err = __stop_machine(take_cpu_down, &tcd_param, cpumask_of(cpu));
if (err) {
set_cpu_active(cpu, true);
@@ -237,7 +234,7 @@
hcpu) == NOTIFY_BAD)
BUG();
- goto out_allowed;
+ goto out_release;
}
BUG_ON(cpu_online(cpu));
@@ -255,8 +252,6 @@
check_for_tasks(cpu);
-out_allowed:
- set_cpus_allowed_ptr(current, old_allowed);
out_release:
cpu_hotplug_done();
if (!err) {
@@ -264,7 +259,6 @@
hcpu) == NOTIFY_BAD)
BUG();
}
- free_cpumask_var(old_allowed);
return err;
}
@@ -272,9 +266,6 @@
{
int err;
- err = stop_machine_create();
- if (err)
- return err;
cpu_maps_update_begin();
if (cpu_hotplug_disabled) {
@@ -286,7 +277,6 @@
out:
cpu_maps_update_done();
- stop_machine_destroy();
return err;
}
EXPORT_SYMBOL(cpu_down);
@@ -367,9 +357,6 @@
{
int cpu, first_cpu, error;
- error = stop_machine_create();
- if (error)
- return error;
cpu_maps_update_begin();
first_cpu = cpumask_first(cpu_online_mask);
/*
@@ -400,7 +387,6 @@
printk(KERN_ERR "Non-boot CPUs are not disabled\n");
}
cpu_maps_update_done();
- stop_machine_destroy();
return error;
}
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index d109467..9a50c5f 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -2182,19 +2182,52 @@
void cpuset_cpus_allowed(struct task_struct *tsk, struct cpumask *pmask)
{
mutex_lock(&callback_mutex);
- cpuset_cpus_allowed_locked(tsk, pmask);
- mutex_unlock(&callback_mutex);
-}
-
-/**
- * cpuset_cpus_allowed_locked - return cpus_allowed mask from a tasks cpuset.
- * Must be called with callback_mutex held.
- **/
-void cpuset_cpus_allowed_locked(struct task_struct *tsk, struct cpumask *pmask)
-{
task_lock(tsk);
guarantee_online_cpus(task_cs(tsk), pmask);
task_unlock(tsk);
+ mutex_unlock(&callback_mutex);
+}
+
+int cpuset_cpus_allowed_fallback(struct task_struct *tsk)
+{
+ const struct cpuset *cs;
+ int cpu;
+
+ rcu_read_lock();
+ cs = task_cs(tsk);
+ if (cs)
+ cpumask_copy(&tsk->cpus_allowed, cs->cpus_allowed);
+ rcu_read_unlock();
+
+ /*
+ * We own tsk->cpus_allowed, nobody can change it under us.
+ *
+ * But we used cs && cs->cpus_allowed lockless and thus can
+ * race with cgroup_attach_task() or update_cpumask() and get
+ * the wrong tsk->cpus_allowed. However, both cases imply the
+ * subsequent cpuset_change_cpumask()->set_cpus_allowed_ptr()
+ * which takes task_rq_lock().
+ *
+ * If we are called after it dropped the lock we must see all
+ * changes in tsk_cs()->cpus_allowed. Otherwise we can temporary
+ * set any mask even if it is not right from task_cs() pov,
+ * the pending set_cpus_allowed_ptr() will fix things.
+ */
+
+ cpu = cpumask_any_and(&tsk->cpus_allowed, cpu_active_mask);
+ if (cpu >= nr_cpu_ids) {
+ /*
+ * Either tsk->cpus_allowed is wrong (see above) or it
+ * is actually empty. The latter case is only possible
+ * if we are racing with remove_tasks_in_empty_cpuset().
+ * Like above we can temporary set any mask and rely on
+ * set_cpus_allowed_ptr() as synchronization point.
+ */
+ cpumask_copy(&tsk->cpus_allowed, cpu_possible_mask);
+ cpu = cpumask_any(cpu_active_mask);
+ }
+
+ return cpu;
}
void cpuset_init_current_mems_allowed(void)
@@ -2383,22 +2416,6 @@
}
/**
- * cpuset_lock - lock out any changes to cpuset structures
- *
- * The out of memory (oom) code needs to mutex_lock cpusets
- * from being changed while it scans the tasklist looking for a
- * task in an overlapping cpuset. Expose callback_mutex via this
- * cpuset_lock() routine, so the oom code can lock it, before
- * locking the task list. The tasklist_lock is a spinlock, so
- * must be taken inside callback_mutex.
- */
-
-void cpuset_lock(void)
-{
- mutex_lock(&callback_mutex);
-}
-
-/**
* cpuset_unlock - release lock on cpuset changes
*
* Undo the lock taken in a previous cpuset_lock() call.
diff --git a/kernel/cred-internals.h b/kernel/cred-internals.h
deleted file mode 100644
index 2dc4fc2..0000000
--- a/kernel/cred-internals.h
+++ /dev/null
@@ -1,21 +0,0 @@
-/* Internal credentials stuff
- *
- * Copyright (C) 2008 Red Hat, Inc. All Rights Reserved.
- * Written by David Howells (dhowells@redhat.com)
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public Licence
- * as published by the Free Software Foundation; either version
- * 2 of the Licence, or (at your option) any later version.
- */
-
-/*
- * user.c
- */
-static inline void sched_switch_user(struct task_struct *p)
-{
-#ifdef CONFIG_USER_SCHED
- sched_move_task(p);
-#endif /* CONFIG_USER_SCHED */
-}
-
diff --git a/kernel/cred.c b/kernel/cred.c
index 62af181..8f3672a 100644
--- a/kernel/cred.c
+++ b/kernel/cred.c
@@ -17,7 +17,6 @@
#include <linux/init_task.h>
#include <linux/security.h>
#include <linux/cn_proc.h>
-#include "cred-internals.h"
#if 0
#define kdebug(FMT, ...) \
@@ -560,8 +559,6 @@
atomic_dec(&old->user->processes);
alter_cred_subscribers(old, -2);
- sched_switch_user(task);
-
/* send notifications */
if (new->uid != old->uid ||
new->euid != old->euid ||
diff --git a/kernel/exit.c b/kernel/exit.c
index 7f2683a..eabca5a 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -55,7 +55,6 @@
#include <asm/unistd.h>
#include <asm/pgtable.h>
#include <asm/mmu_context.h>
-#include "cred-internals.h"
static void exit_mm(struct task_struct * tsk);
diff --git a/kernel/module.c b/kernel/module.c
index b8a1e31..e256458 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -724,16 +724,8 @@
return -EFAULT;
name[MODULE_NAME_LEN-1] = '\0';
- /* Create stop_machine threads since free_module relies on
- * a non-failing stop_machine call. */
- ret = stop_machine_create();
- if (ret)
- return ret;
-
- if (mutex_lock_interruptible(&module_mutex) != 0) {
- ret = -EINTR;
- goto out_stop;
- }
+ if (mutex_lock_interruptible(&module_mutex) != 0)
+ return -EINTR;
mod = find_module(name);
if (!mod) {
@@ -793,8 +785,6 @@
out:
mutex_unlock(&module_mutex);
-out_stop:
- stop_machine_destroy();
return ret;
}
diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c
index 077defb..6535ac8 100644
--- a/kernel/rcutorture.c
+++ b/kernel/rcutorture.c
@@ -671,7 +671,7 @@
.sync = synchronize_sched_expedited,
.cb_barrier = NULL,
.fqs = rcu_sched_force_quiescent_state,
- .stats = rcu_expedited_torture_stats,
+ .stats = NULL,
.irq_capable = 1,
.name = "sched_expedited"
};
diff --git a/kernel/sched.c b/kernel/sched.c
index 5cd607e..1d93cd0 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -55,9 +55,9 @@
#include <linux/cpu.h>
#include <linux/cpuset.h>
#include <linux/percpu.h>
-#include <linux/kthread.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
+#include <linux/stop_machine.h>
#include <linux/sysctl.h>
#include <linux/syscalls.h>
#include <linux/times.h>
@@ -503,8 +503,11 @@
#define CPU_LOAD_IDX_MAX 5
unsigned long cpu_load[CPU_LOAD_IDX_MAX];
#ifdef CONFIG_NO_HZ
+ u64 nohz_stamp;
unsigned char in_nohz_recently;
#endif
+ unsigned int skip_clock_update;
+
/* capture load from *all* tasks on this cpu: */
struct load_weight load;
unsigned long nr_load_updates;
@@ -546,15 +549,13 @@
int post_schedule;
int active_balance;
int push_cpu;
+ struct cpu_stop_work active_balance_work;
/* cpu of this runqueue: */
int cpu;
int online;
unsigned long avg_load_per_task;
- struct task_struct *migration_thread;
- struct list_head migration_queue;
-
u64 rt_avg;
u64 age_stamp;
u64 idle_stamp;
@@ -602,6 +603,13 @@
void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags)
{
rq->curr->sched_class->check_preempt_curr(rq, p, flags);
+
+ /*
+ * A queue event has occurred, and we're going to schedule. In
+ * this case, we can save a useless back to back clock update.
+ */
+ if (test_tsk_need_resched(p))
+ rq->skip_clock_update = 1;
}
static inline int cpu_of(struct rq *rq)
@@ -636,7 +644,8 @@
inline void update_rq_clock(struct rq *rq)
{
- rq->clock = sched_clock_cpu(cpu_of(rq));
+ if (!rq->skip_clock_update)
+ rq->clock = sched_clock_cpu(cpu_of(rq));
}
/*
@@ -914,16 +923,12 @@
#endif /* __ARCH_WANT_UNLOCKED_CTXSW */
/*
- * Check whether the task is waking, we use this to synchronize against
- * ttwu() so that task_cpu() reports a stable number.
- *
- * We need to make an exception for PF_STARTING tasks because the fork
- * path might require task_rq_lock() to work, eg. it can call
- * set_cpus_allowed_ptr() from the cpuset clone_ns code.
+ * Check whether the task is waking, we use this to synchronize ->cpus_allowed
+ * against ttwu().
*/
static inline int task_is_waking(struct task_struct *p)
{
- return unlikely((p->state == TASK_WAKING) && !(p->flags & PF_STARTING));
+ return unlikely(p->state == TASK_WAKING);
}
/*
@@ -936,11 +941,9 @@
struct rq *rq;
for (;;) {
- while (task_is_waking(p))
- cpu_relax();
rq = task_rq(p);
raw_spin_lock(&rq->lock);
- if (likely(rq == task_rq(p) && !task_is_waking(p)))
+ if (likely(rq == task_rq(p)))
return rq;
raw_spin_unlock(&rq->lock);
}
@@ -957,12 +960,10 @@
struct rq *rq;
for (;;) {
- while (task_is_waking(p))
- cpu_relax();
local_irq_save(*flags);
rq = task_rq(p);
raw_spin_lock(&rq->lock);
- if (likely(rq == task_rq(p) && !task_is_waking(p)))
+ if (likely(rq == task_rq(p)))
return rq;
raw_spin_unlock_irqrestore(&rq->lock, *flags);
}
@@ -1239,6 +1240,17 @@
if (!tsk_is_polling(rq->idle))
smp_send_reschedule(cpu);
}
+
+int nohz_ratelimit(int cpu)
+{
+ struct rq *rq = cpu_rq(cpu);
+ u64 diff = rq->clock - rq->nohz_stamp;
+
+ rq->nohz_stamp = rq->clock;
+
+ return diff < (NSEC_PER_SEC / HZ) >> 1;
+}
+
#endif /* CONFIG_NO_HZ */
static u64 sched_avg_period(void)
@@ -1781,8 +1793,6 @@
raw_spin_lock_nested(&rq1->lock, SINGLE_DEPTH_NESTING);
}
}
- update_rq_clock(rq1);
- update_rq_clock(rq2);
}
/*
@@ -1813,7 +1823,7 @@
}
#endif
-static void calc_load_account_active(struct rq *this_rq);
+static void calc_load_account_idle(struct rq *this_rq);
static void update_sysctl(void);
static int get_update_sysctl_factor(void);
@@ -1870,62 +1880,43 @@
p->se.load.inv_weight = prio_to_wmult[p->static_prio - MAX_RT_PRIO];
}
-static void update_avg(u64 *avg, u64 sample)
+static void enqueue_task(struct rq *rq, struct task_struct *p, int flags)
{
- s64 diff = sample - *avg;
- *avg += diff >> 3;
-}
-
-static void
-enqueue_task(struct rq *rq, struct task_struct *p, int wakeup, bool head)
-{
- if (wakeup)
- p->se.start_runtime = p->se.sum_exec_runtime;
-
+ update_rq_clock(rq);
sched_info_queued(p);
- p->sched_class->enqueue_task(rq, p, wakeup, head);
+ p->sched_class->enqueue_task(rq, p, flags);
p->se.on_rq = 1;
}
-static void dequeue_task(struct rq *rq, struct task_struct *p, int sleep)
+static void dequeue_task(struct rq *rq, struct task_struct *p, int flags)
{
- if (sleep) {
- if (p->se.last_wakeup) {
- update_avg(&p->se.avg_overlap,
- p->se.sum_exec_runtime - p->se.last_wakeup);
- p->se.last_wakeup = 0;
- } else {
- update_avg(&p->se.avg_wakeup,
- sysctl_sched_wakeup_granularity);
- }
- }
-
+ update_rq_clock(rq);
sched_info_dequeued(p);
- p->sched_class->dequeue_task(rq, p, sleep);
+ p->sched_class->dequeue_task(rq, p, flags);
p->se.on_rq = 0;
}
/*
* activate_task - move a task to the runqueue.
*/
-static void activate_task(struct rq *rq, struct task_struct *p, int wakeup)
+static void activate_task(struct rq *rq, struct task_struct *p, int flags)
{
if (task_contributes_to_load(p))
rq->nr_uninterruptible--;
- enqueue_task(rq, p, wakeup, false);
+ enqueue_task(rq, p, flags);
inc_nr_running(rq);
}
/*
* deactivate_task - remove a task from the runqueue.
*/
-static void deactivate_task(struct rq *rq, struct task_struct *p, int sleep)
+static void deactivate_task(struct rq *rq, struct task_struct *p, int flags)
{
if (task_contributes_to_load(p))
rq->nr_uninterruptible++;
- dequeue_task(rq, p, sleep);
+ dequeue_task(rq, p, flags);
dec_nr_running(rq);
}
@@ -2054,21 +2045,18 @@
__set_task_cpu(p, new_cpu);
}
-struct migration_req {
- struct list_head list;
-
+struct migration_arg {
struct task_struct *task;
int dest_cpu;
-
- struct completion done;
};
+static int migration_cpu_stop(void *data);
+
/*
* The task's runqueue lock must be held.
* Returns true if you have to wait for migration thread.
*/
-static int
-migrate_task(struct task_struct *p, int dest_cpu, struct migration_req *req)
+static bool migrate_task(struct task_struct *p, int dest_cpu)
{
struct rq *rq = task_rq(p);
@@ -2076,15 +2064,7 @@
* If the task is not on a runqueue (and not running), then
* the next wake-up will properly place the task.
*/
- if (!p->se.on_rq && !task_running(rq, p))
- return 0;
-
- init_completion(&req->done);
- req->task = p;
- req->dest_cpu = dest_cpu;
- list_add(&req->list, &rq->migration_queue);
-
- return 1;
+ return p->se.on_rq || task_running(rq, p);
}
/*
@@ -2142,7 +2122,7 @@
* just go back and repeat.
*/
rq = task_rq_lock(p, &flags);
- trace_sched_wait_task(rq, p);
+ trace_sched_wait_task(p);
running = task_running(rq, p);
on_rq = p->se.on_rq;
ncsw = 0;
@@ -2240,6 +2220,9 @@
}
#ifdef CONFIG_SMP
+/*
+ * ->cpus_allowed is protected by either TASK_WAKING or rq->lock held.
+ */
static int select_fallback_rq(int cpu, struct task_struct *p)
{
int dest_cpu;
@@ -2256,12 +2239,8 @@
return dest_cpu;
/* No more Mr. Nice Guy. */
- if (dest_cpu >= nr_cpu_ids) {
- rcu_read_lock();
- cpuset_cpus_allowed_locked(p, &p->cpus_allowed);
- rcu_read_unlock();
- dest_cpu = cpumask_any_and(cpu_active_mask, &p->cpus_allowed);
-
+ if (unlikely(dest_cpu >= nr_cpu_ids)) {
+ dest_cpu = cpuset_cpus_allowed_fallback(p);
/*
* Don't tell them about moving exiting tasks or
* kernel threads (both mm NULL), since they never
@@ -2278,17 +2257,12 @@
}
/*
- * Gets called from 3 sites (exec, fork, wakeup), since it is called without
- * holding rq->lock we need to ensure ->cpus_allowed is stable, this is done
- * by:
- *
- * exec: is unstable, retry loop
- * fork & wake-up: serialize ->cpus_allowed against TASK_WAKING
+ * The caller (fork, wakeup) owns TASK_WAKING, ->cpus_allowed is stable.
*/
static inline
-int select_task_rq(struct task_struct *p, int sd_flags, int wake_flags)
+int select_task_rq(struct rq *rq, struct task_struct *p, int sd_flags, int wake_flags)
{
- int cpu = p->sched_class->select_task_rq(p, sd_flags, wake_flags);
+ int cpu = p->sched_class->select_task_rq(rq, p, sd_flags, wake_flags);
/*
* In order not to call set_task_cpu() on a blocking task we need
@@ -2306,6 +2280,12 @@
return cpu;
}
+
+static void update_avg(u64 *avg, u64 sample)
+{
+ s64 diff = sample - *avg;
+ *avg += diff >> 3;
+}
#endif
/***
@@ -2327,16 +2307,13 @@
{
int cpu, orig_cpu, this_cpu, success = 0;
unsigned long flags;
+ unsigned long en_flags = ENQUEUE_WAKEUP;
struct rq *rq;
- if (!sched_feat(SYNC_WAKEUPS))
- wake_flags &= ~WF_SYNC;
-
this_cpu = get_cpu();
smp_wmb();
rq = task_rq_lock(p, &flags);
- update_rq_clock(rq);
if (!(p->state & state))
goto out;
@@ -2356,28 +2333,26 @@
*
* First fix up the nr_uninterruptible count:
*/
- if (task_contributes_to_load(p))
- rq->nr_uninterruptible--;
+ if (task_contributes_to_load(p)) {
+ if (likely(cpu_online(orig_cpu)))
+ rq->nr_uninterruptible--;
+ else
+ this_rq()->nr_uninterruptible--;
+ }
p->state = TASK_WAKING;
- if (p->sched_class->task_waking)
+ if (p->sched_class->task_waking) {
p->sched_class->task_waking(rq, p);
-
- __task_rq_unlock(rq);
-
- cpu = select_task_rq(p, SD_BALANCE_WAKE, wake_flags);
- if (cpu != orig_cpu) {
- /*
- * Since we migrate the task without holding any rq->lock,
- * we need to be careful with task_rq_lock(), since that
- * might end up locking an invalid rq.
- */
- set_task_cpu(p, cpu);
+ en_flags |= ENQUEUE_WAKING;
}
+ cpu = select_task_rq(rq, p, SD_BALANCE_WAKE, wake_flags);
+ if (cpu != orig_cpu)
+ set_task_cpu(p, cpu);
+ __task_rq_unlock(rq);
+
rq = cpu_rq(cpu);
raw_spin_lock(&rq->lock);
- update_rq_clock(rq);
/*
* We migrated the task without holding either rq->lock, however
@@ -2405,36 +2380,20 @@
out_activate:
#endif /* CONFIG_SMP */
- schedstat_inc(p, se.nr_wakeups);
+ schedstat_inc(p, se.statistics.nr_wakeups);
if (wake_flags & WF_SYNC)
- schedstat_inc(p, se.nr_wakeups_sync);
+ schedstat_inc(p, se.statistics.nr_wakeups_sync);
if (orig_cpu != cpu)
- schedstat_inc(p, se.nr_wakeups_migrate);
+ schedstat_inc(p, se.statistics.nr_wakeups_migrate);
if (cpu == this_cpu)
- schedstat_inc(p, se.nr_wakeups_local);
+ schedstat_inc(p, se.statistics.nr_wakeups_local);
else
- schedstat_inc(p, se.nr_wakeups_remote);
- activate_task(rq, p, 1);
+ schedstat_inc(p, se.statistics.nr_wakeups_remote);
+ activate_task(rq, p, en_flags);
success = 1;
- /*
- * Only attribute actual wakeups done by this task.
- */
- if (!in_interrupt()) {
- struct sched_entity *se = ¤t->se;
- u64 sample = se->sum_exec_runtime;
-
- if (se->last_wakeup)
- sample -= se->last_wakeup;
- else
- sample -= se->start_runtime;
- update_avg(&se->avg_wakeup, sample);
-
- se->last_wakeup = se->sum_exec_runtime;
- }
-
out_running:
- trace_sched_wakeup(rq, p, success);
+ trace_sched_wakeup(p, success);
check_preempt_curr(rq, p, wake_flags);
p->state = TASK_RUNNING;
@@ -2494,42 +2453,9 @@
p->se.sum_exec_runtime = 0;
p->se.prev_sum_exec_runtime = 0;
p->se.nr_migrations = 0;
- p->se.last_wakeup = 0;
- p->se.avg_overlap = 0;
- p->se.start_runtime = 0;
- p->se.avg_wakeup = sysctl_sched_wakeup_granularity;
#ifdef CONFIG_SCHEDSTATS
- p->se.wait_start = 0;
- p->se.wait_max = 0;
- p->se.wait_count = 0;
- p->se.wait_sum = 0;
-
- p->se.sleep_start = 0;
- p->se.sleep_max = 0;
- p->se.sum_sleep_runtime = 0;
-
- p->se.block_start = 0;
- p->se.block_max = 0;
- p->se.exec_max = 0;
- p->se.slice_max = 0;
-
- p->se.nr_migrations_cold = 0;
- p->se.nr_failed_migrations_affine = 0;
- p->se.nr_failed_migrations_running = 0;
- p->se.nr_failed_migrations_hot = 0;
- p->se.nr_forced_migrations = 0;
-
- p->se.nr_wakeups = 0;
- p->se.nr_wakeups_sync = 0;
- p->se.nr_wakeups_migrate = 0;
- p->se.nr_wakeups_local = 0;
- p->se.nr_wakeups_remote = 0;
- p->se.nr_wakeups_affine = 0;
- p->se.nr_wakeups_affine_attempts = 0;
- p->se.nr_wakeups_passive = 0;
- p->se.nr_wakeups_idle = 0;
-
+ memset(&p->se.statistics, 0, sizeof(p->se.statistics));
#endif
INIT_LIST_HEAD(&p->rt.run_list);
@@ -2550,11 +2476,11 @@
__sched_fork(p);
/*
- * We mark the process as waking here. This guarantees that
+ * We mark the process as running here. This guarantees that
* nobody will actually run it, and a signal or other external
* event cannot wake it up and insert it on the runqueue either.
*/
- p->state = TASK_WAKING;
+ p->state = TASK_RUNNING;
/*
* Revert to default priority/policy on fork if requested.
@@ -2621,31 +2547,27 @@
int cpu __maybe_unused = get_cpu();
#ifdef CONFIG_SMP
+ rq = task_rq_lock(p, &flags);
+ p->state = TASK_WAKING;
+
/*
* Fork balancing, do it here and not earlier because:
* - cpus_allowed can change in the fork path
* - any previously selected cpu might disappear through hotplug
*
- * We still have TASK_WAKING but PF_STARTING is gone now, meaning
- * ->cpus_allowed is stable, we have preemption disabled, meaning
- * cpu_online_mask is stable.
+ * We set TASK_WAKING so that select_task_rq() can drop rq->lock
+ * without people poking at ->cpus_allowed.
*/
- cpu = select_task_rq(p, SD_BALANCE_FORK, 0);
+ cpu = select_task_rq(rq, p, SD_BALANCE_FORK, 0);
set_task_cpu(p, cpu);
+
+ p->state = TASK_RUNNING;
+ task_rq_unlock(rq, &flags);
#endif
- /*
- * Since the task is not on the rq and we still have TASK_WAKING set
- * nobody else will migrate this task.
- */
- rq = cpu_rq(cpu);
- raw_spin_lock_irqsave(&rq->lock, flags);
-
- BUG_ON(p->state != TASK_WAKING);
- p->state = TASK_RUNNING;
- update_rq_clock(rq);
+ rq = task_rq_lock(p, &flags);
activate_task(rq, p, 0);
- trace_sched_wakeup_new(rq, p, 1);
+ trace_sched_wakeup_new(p, 1);
check_preempt_curr(rq, p, WF_FORK);
#ifdef CONFIG_SMP
if (p->sched_class->task_woken)
@@ -2865,7 +2787,7 @@
struct mm_struct *mm, *oldmm;
prepare_task_switch(rq, prev, next);
- trace_sched_switch(rq, prev, next);
+ trace_sched_switch(prev, next);
mm = next->mm;
oldmm = prev->active_mm;
/*
@@ -2982,6 +2904,61 @@
unsigned long avenrun[3];
EXPORT_SYMBOL(avenrun);
+static long calc_load_fold_active(struct rq *this_rq)
+{
+ long nr_active, delta = 0;
+
+ nr_active = this_rq->nr_running;
+ nr_active += (long) this_rq->nr_uninterruptible;
+
+ if (nr_active != this_rq->calc_load_active) {
+ delta = nr_active - this_rq->calc_load_active;
+ this_rq->calc_load_active = nr_active;
+ }
+
+ return delta;
+}
+
+#ifdef CONFIG_NO_HZ
+/*
+ * For NO_HZ we delay the active fold to the next LOAD_FREQ update.
+ *
+ * When making the ILB scale, we should try to pull this in as well.
+ */
+static atomic_long_t calc_load_tasks_idle;
+
+static void calc_load_account_idle(struct rq *this_rq)
+{
+ long delta;
+
+ delta = calc_load_fold_active(this_rq);
+ if (delta)
+ atomic_long_add(delta, &calc_load_tasks_idle);
+}
+
+static long calc_load_fold_idle(void)
+{
+ long delta = 0;
+
+ /*
+ * Its got a race, we don't care...
+ */
+ if (atomic_long_read(&calc_load_tasks_idle))
+ delta = atomic_long_xchg(&calc_load_tasks_idle, 0);
+
+ return delta;
+}
+#else
+static void calc_load_account_idle(struct rq *this_rq)
+{
+}
+
+static inline long calc_load_fold_idle(void)
+{
+ return 0;
+}
+#endif
+
/**
* get_avenrun - get the load average array
* @loads: pointer to dest load array
@@ -3028,20 +3005,22 @@
}
/*
- * Either called from update_cpu_load() or from a cpu going idle
+ * Called from update_cpu_load() to periodically update this CPU's
+ * active count.
*/
static void calc_load_account_active(struct rq *this_rq)
{
- long nr_active, delta;
+ long delta;
- nr_active = this_rq->nr_running;
- nr_active += (long) this_rq->nr_uninterruptible;
+ if (time_before(jiffies, this_rq->calc_load_update))
+ return;
- if (nr_active != this_rq->calc_load_active) {
- delta = nr_active - this_rq->calc_load_active;
- this_rq->calc_load_active = nr_active;
+ delta = calc_load_fold_active(this_rq);
+ delta += calc_load_fold_idle();
+ if (delta)
atomic_long_add(delta, &calc_load_tasks);
- }
+
+ this_rq->calc_load_update += LOAD_FREQ;
}
/*
@@ -3073,10 +3052,7 @@
this_rq->cpu_load[i] = (old_load*(scale-1) + new_load) >> i;
}
- if (time_after_eq(jiffies, this_rq->calc_load_update)) {
- this_rq->calc_load_update += LOAD_FREQ;
- calc_load_account_active(this_rq);
- }
+ calc_load_account_active(this_rq);
}
#ifdef CONFIG_SMP
@@ -3088,44 +3064,27 @@
void sched_exec(void)
{
struct task_struct *p = current;
- struct migration_req req;
- int dest_cpu, this_cpu;
unsigned long flags;
struct rq *rq;
-
-again:
- this_cpu = get_cpu();
- dest_cpu = select_task_rq(p, SD_BALANCE_EXEC, 0);
- if (dest_cpu == this_cpu) {
- put_cpu();
- return;
- }
+ int dest_cpu;
rq = task_rq_lock(p, &flags);
- put_cpu();
+ dest_cpu = p->sched_class->select_task_rq(rq, p, SD_BALANCE_EXEC, 0);
+ if (dest_cpu == smp_processor_id())
+ goto unlock;
/*
* select_task_rq() can race against ->cpus_allowed
*/
- if (!cpumask_test_cpu(dest_cpu, &p->cpus_allowed)
- || unlikely(!cpu_active(dest_cpu))) {
+ if (cpumask_test_cpu(dest_cpu, &p->cpus_allowed) &&
+ likely(cpu_active(dest_cpu)) && migrate_task(p, dest_cpu)) {
+ struct migration_arg arg = { p, dest_cpu };
+
task_rq_unlock(rq, &flags);
- goto again;
- }
-
- /* force the process onto the specified CPU */
- if (migrate_task(p, dest_cpu, &req)) {
- /* Need to wait for migration thread (might exit: take ref). */
- struct task_struct *mt = rq->migration_thread;
-
- get_task_struct(mt);
- task_rq_unlock(rq, &flags);
- wake_up_process(mt);
- put_task_struct(mt);
- wait_for_completion(&req.done);
-
+ stop_one_cpu(cpu_of(rq), migration_cpu_stop, &arg);
return;
}
+unlock:
task_rq_unlock(rq, &flags);
}
@@ -3597,23 +3556,9 @@
static void put_prev_task(struct rq *rq, struct task_struct *prev)
{
- if (prev->state == TASK_RUNNING) {
- u64 runtime = prev->se.sum_exec_runtime;
-
- runtime -= prev->se.prev_sum_exec_runtime;
- runtime = min_t(u64, runtime, 2*sysctl_sched_migration_cost);
-
- /*
- * In order to avoid avg_overlap growing stale when we are
- * indeed overlapping and hence not getting put to sleep, grow
- * the avg_overlap on preemption.
- *
- * We use the average preemption runtime because that
- * correlates to the amount of cache footprint a task can
- * build up.
- */
- update_avg(&prev->se.avg_overlap, runtime);
- }
+ if (prev->se.on_rq)
+ update_rq_clock(rq);
+ rq->skip_clock_update = 0;
prev->sched_class->put_prev_task(rq, prev);
}
@@ -3676,14 +3621,13 @@
hrtick_clear(rq);
raw_spin_lock_irq(&rq->lock);
- update_rq_clock(rq);
clear_tsk_need_resched(prev);
if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) {
if (unlikely(signal_pending_state(prev->state, prev)))
prev->state = TASK_RUNNING;
else
- deactivate_task(rq, prev, 1);
+ deactivate_task(rq, prev, DEQUEUE_SLEEP);
switch_count = &prev->nvcsw;
}
@@ -4006,8 +3950,7 @@
if (!x->done) {
DECLARE_WAITQUEUE(wait, current);
- wait.flags |= WQ_FLAG_EXCLUSIVE;
- __add_wait_queue_tail(&x->wait, &wait);
+ __add_wait_queue_tail_exclusive(&x->wait, &wait);
do {
if (signal_pending_state(state, current)) {
timeout = -ERESTARTSYS;
@@ -4233,7 +4176,6 @@
BUG_ON(prio < 0 || prio > MAX_PRIO);
rq = task_rq_lock(p, &flags);
- update_rq_clock(rq);
oldprio = p->prio;
prev_class = p->sched_class;
@@ -4254,7 +4196,7 @@
if (running)
p->sched_class->set_curr_task(rq);
if (on_rq) {
- enqueue_task(rq, p, 0, oldprio < prio);
+ enqueue_task(rq, p, oldprio < prio ? ENQUEUE_HEAD : 0);
check_class_changed(rq, p, prev_class, oldprio, running);
}
@@ -4276,7 +4218,6 @@
* the task might be in the middle of scheduling on another CPU.
*/
rq = task_rq_lock(p, &flags);
- update_rq_clock(rq);
/*
* The RT priorities are set via sched_setscheduler(), but we still
* allow the 'normal' nice value to be set - but as expected
@@ -4298,7 +4239,7 @@
delta = p->prio - old_prio;
if (on_rq) {
- enqueue_task(rq, p, 0, false);
+ enqueue_task(rq, p, 0);
/*
* If the task increased its priority or is running and
* lowered its priority, then reschedule its CPU:
@@ -4559,7 +4500,6 @@
raw_spin_unlock_irqrestore(&p->pi_lock, flags);
goto recheck;
}
- update_rq_clock(rq);
on_rq = p->se.on_rq;
running = task_current(rq, p);
if (on_rq)
@@ -5296,17 +5236,15 @@
/*
* This is how migration works:
*
- * 1) we queue a struct migration_req structure in the source CPU's
- * runqueue and wake up that CPU's migration thread.
- * 2) we down() the locked semaphore => thread blocks.
- * 3) migration thread wakes up (implicitly it forces the migrated
- * thread off the CPU)
- * 4) it gets the migration request and checks whether the migrated
- * task is still in the wrong runqueue.
- * 5) if it's in the wrong runqueue then the migration thread removes
+ * 1) we invoke migration_cpu_stop() on the target CPU using
+ * stop_one_cpu().
+ * 2) stopper starts to run (implicitly forcing the migrated thread
+ * off the CPU)
+ * 3) it checks whether the migrated task is still in the wrong runqueue.
+ * 4) if it's in the wrong runqueue then the migration thread removes
* it and puts it into the right queue.
- * 6) migration thread up()s the semaphore.
- * 7) we wake up and the migration is done.
+ * 5) stopper completes and stop_one_cpu() returns and the migration
+ * is done.
*/
/*
@@ -5320,12 +5258,23 @@
*/
int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
{
- struct migration_req req;
unsigned long flags;
struct rq *rq;
+ unsigned int dest_cpu;
int ret = 0;
+ /*
+ * Serialize against TASK_WAKING so that ttwu() and wunt() can
+ * drop the rq->lock and still rely on ->cpus_allowed.
+ */
+again:
+ while (task_is_waking(p))
+ cpu_relax();
rq = task_rq_lock(p, &flags);
+ if (task_is_waking(p)) {
+ task_rq_unlock(rq, &flags);
+ goto again;
+ }
if (!cpumask_intersects(new_mask, cpu_active_mask)) {
ret = -EINVAL;
@@ -5349,15 +5298,12 @@
if (cpumask_test_cpu(task_cpu(p), new_mask))
goto out;
- if (migrate_task(p, cpumask_any_and(cpu_active_mask, new_mask), &req)) {
+ dest_cpu = cpumask_any_and(cpu_active_mask, new_mask);
+ if (migrate_task(p, dest_cpu)) {
+ struct migration_arg arg = { p, dest_cpu };
/* Need help from migration thread: drop lock and wait. */
- struct task_struct *mt = rq->migration_thread;
-
- get_task_struct(mt);
task_rq_unlock(rq, &flags);
- wake_up_process(mt);
- put_task_struct(mt);
- wait_for_completion(&req.done);
+ stop_one_cpu(cpu_of(rq), migration_cpu_stop, &arg);
tlb_migrate_finish(p->mm);
return 0;
}
@@ -5415,98 +5361,49 @@
return ret;
}
-#define RCU_MIGRATION_IDLE 0
-#define RCU_MIGRATION_NEED_QS 1
-#define RCU_MIGRATION_GOT_QS 2
-#define RCU_MIGRATION_MUST_SYNC 3
-
/*
- * migration_thread - this is a highprio system thread that performs
- * thread migration by bumping thread off CPU then 'pushing' onto
- * another runqueue.
+ * migration_cpu_stop - this will be executed by a highprio stopper thread
+ * and performs thread migration by bumping thread off CPU then
+ * 'pushing' onto another runqueue.
*/
-static int migration_thread(void *data)
+static int migration_cpu_stop(void *data)
{
- int badcpu;
- int cpu = (long)data;
- struct rq *rq;
+ struct migration_arg *arg = data;
- rq = cpu_rq(cpu);
- BUG_ON(rq->migration_thread != current);
-
- set_current_state(TASK_INTERRUPTIBLE);
- while (!kthread_should_stop()) {
- struct migration_req *req;
- struct list_head *head;
-
- raw_spin_lock_irq(&rq->lock);
-
- if (cpu_is_offline(cpu)) {
- raw_spin_unlock_irq(&rq->lock);
- break;
- }
-
- if (rq->active_balance) {
- active_load_balance(rq, cpu);
- rq->active_balance = 0;
- }
-
- head = &rq->migration_queue;
-
- if (list_empty(head)) {
- raw_spin_unlock_irq(&rq->lock);
- schedule();
- set_current_state(TASK_INTERRUPTIBLE);
- continue;
- }
- req = list_entry(head->next, struct migration_req, list);
- list_del_init(head->next);
-
- if (req->task != NULL) {
- raw_spin_unlock(&rq->lock);
- __migrate_task(req->task, cpu, req->dest_cpu);
- } else if (likely(cpu == (badcpu = smp_processor_id()))) {
- req->dest_cpu = RCU_MIGRATION_GOT_QS;
- raw_spin_unlock(&rq->lock);
- } else {
- req->dest_cpu = RCU_MIGRATION_MUST_SYNC;
- raw_spin_unlock(&rq->lock);
- WARN_ONCE(1, "migration_thread() on CPU %d, expected %d\n", badcpu, cpu);
- }
- local_irq_enable();
-
- complete(&req->done);
- }
- __set_current_state(TASK_RUNNING);
-
+ /*
+ * The original target cpu might have gone down and we might
+ * be on another cpu but it doesn't matter.
+ */
+ local_irq_disable();
+ __migrate_task(arg->task, raw_smp_processor_id(), arg->dest_cpu);
+ local_irq_enable();
return 0;
}
#ifdef CONFIG_HOTPLUG_CPU
-
-static int __migrate_task_irq(struct task_struct *p, int src_cpu, int dest_cpu)
-{
- int ret;
-
- local_irq_disable();
- ret = __migrate_task(p, src_cpu, dest_cpu);
- local_irq_enable();
- return ret;
-}
-
/*
* Figure out where task on dead CPU should go, use force if necessary.
*/
-static void move_task_off_dead_cpu(int dead_cpu, struct task_struct *p)
+void move_task_off_dead_cpu(int dead_cpu, struct task_struct *p)
{
- int dest_cpu;
+ struct rq *rq = cpu_rq(dead_cpu);
+ int needs_cpu, uninitialized_var(dest_cpu);
+ unsigned long flags;
-again:
- dest_cpu = select_fallback_rq(dead_cpu, p);
+ local_irq_save(flags);
- /* It can have affinity changed while we were choosing. */
- if (unlikely(!__migrate_task_irq(p, dead_cpu, dest_cpu)))
- goto again;
+ raw_spin_lock(&rq->lock);
+ needs_cpu = (task_cpu(p) == dead_cpu) && (p->state != TASK_WAKING);
+ if (needs_cpu)
+ dest_cpu = select_fallback_rq(dead_cpu, p);
+ raw_spin_unlock(&rq->lock);
+ /*
+ * It can only fail if we race with set_cpus_allowed(),
+ * in the racer should migrate the task anyway.
+ */
+ if (needs_cpu)
+ __migrate_task(p, dead_cpu, dest_cpu);
+ local_irq_restore(flags);
}
/*
@@ -5570,7 +5467,6 @@
__setscheduler(rq, p, SCHED_FIFO, MAX_RT_PRIO-1);
- update_rq_clock(rq);
activate_task(rq, p, 0);
raw_spin_unlock_irqrestore(&rq->lock, flags);
@@ -5625,7 +5521,6 @@
for ( ; ; ) {
if (!rq->nr_running)
break;
- update_rq_clock(rq);
next = pick_next_task(rq);
if (!next)
break;
@@ -5848,35 +5743,20 @@
static int __cpuinit
migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
{
- struct task_struct *p;
int cpu = (long)hcpu;
unsigned long flags;
- struct rq *rq;
+ struct rq *rq = cpu_rq(cpu);
switch (action) {
case CPU_UP_PREPARE:
case CPU_UP_PREPARE_FROZEN:
- p = kthread_create(migration_thread, hcpu, "migration/%d", cpu);
- if (IS_ERR(p))
- return NOTIFY_BAD;
- kthread_bind(p, cpu);
- /* Must be high prio: stop_machine expects to yield to it. */
- rq = task_rq_lock(p, &flags);
- __setscheduler(rq, p, SCHED_FIFO, MAX_RT_PRIO-1);
- task_rq_unlock(rq, &flags);
- get_task_struct(p);
- cpu_rq(cpu)->migration_thread = p;
rq->calc_load_update = calc_load_update;
break;
case CPU_ONLINE:
case CPU_ONLINE_FROZEN:
- /* Strictly unnecessary, as first user will wake it. */
- wake_up_process(cpu_rq(cpu)->migration_thread);
-
/* Update our root-domain */
- rq = cpu_rq(cpu);
raw_spin_lock_irqsave(&rq->lock, flags);
if (rq->rd) {
BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span));
@@ -5887,61 +5767,24 @@
break;
#ifdef CONFIG_HOTPLUG_CPU
- case CPU_UP_CANCELED:
- case CPU_UP_CANCELED_FROZEN:
- if (!cpu_rq(cpu)->migration_thread)
- break;
- /* Unbind it from offline cpu so it can run. Fall thru. */
- kthread_bind(cpu_rq(cpu)->migration_thread,
- cpumask_any(cpu_online_mask));
- kthread_stop(cpu_rq(cpu)->migration_thread);
- put_task_struct(cpu_rq(cpu)->migration_thread);
- cpu_rq(cpu)->migration_thread = NULL;
- break;
-
case CPU_DEAD:
case CPU_DEAD_FROZEN:
- cpuset_lock(); /* around calls to cpuset_cpus_allowed_lock() */
migrate_live_tasks(cpu);
- rq = cpu_rq(cpu);
- kthread_stop(rq->migration_thread);
- put_task_struct(rq->migration_thread);
- rq->migration_thread = NULL;
/* Idle task back to normal (off runqueue, low prio) */
raw_spin_lock_irq(&rq->lock);
- update_rq_clock(rq);
deactivate_task(rq, rq->idle, 0);
__setscheduler(rq, rq->idle, SCHED_NORMAL, 0);
rq->idle->sched_class = &idle_sched_class;
migrate_dead_tasks(cpu);
raw_spin_unlock_irq(&rq->lock);
- cpuset_unlock();
migrate_nr_uninterruptible(rq);
BUG_ON(rq->nr_running != 0);
calc_global_load_remove(rq);
- /*
- * No need to migrate the tasks: it was best-effort if
- * they didn't take sched_hotcpu_mutex. Just wake up
- * the requestors.
- */
- raw_spin_lock_irq(&rq->lock);
- while (!list_empty(&rq->migration_queue)) {
- struct migration_req *req;
-
- req = list_entry(rq->migration_queue.next,
- struct migration_req, list);
- list_del_init(&req->list);
- raw_spin_unlock_irq(&rq->lock);
- complete(&req->done);
- raw_spin_lock_irq(&rq->lock);
- }
- raw_spin_unlock_irq(&rq->lock);
break;
case CPU_DYING:
case CPU_DYING_FROZEN:
/* Update our root-domain */
- rq = cpu_rq(cpu);
raw_spin_lock_irqsave(&rq->lock, flags);
if (rq->rd) {
BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span));
@@ -6272,6 +6115,9 @@
struct rq *rq = cpu_rq(cpu);
struct sched_domain *tmp;
+ for (tmp = sd; tmp; tmp = tmp->parent)
+ tmp->span_weight = cpumask_weight(sched_domain_span(tmp));
+
/* Remove the sched domains which do not contribute to scheduling. */
for (tmp = sd; tmp; ) {
struct sched_domain *parent = tmp->parent;
@@ -7755,10 +7601,8 @@
rq->push_cpu = 0;
rq->cpu = i;
rq->online = 0;
- rq->migration_thread = NULL;
rq->idle_stamp = 0;
rq->avg_idle = 2*sysctl_sched_migration_cost;
- INIT_LIST_HEAD(&rq->migration_queue);
rq_attach_root(rq, &def_root_domain);
#endif
init_rq_hrtick(rq);
@@ -7859,7 +7703,6 @@
{
int on_rq;
- update_rq_clock(rq);
on_rq = p->se.on_rq;
if (on_rq)
deactivate_task(rq, p, 0);
@@ -7886,9 +7729,9 @@
p->se.exec_start = 0;
#ifdef CONFIG_SCHEDSTATS
- p->se.wait_start = 0;
- p->se.sleep_start = 0;
- p->se.block_start = 0;
+ p->se.statistics.wait_start = 0;
+ p->se.statistics.sleep_start = 0;
+ p->se.statistics.block_start = 0;
#endif
if (!rt_task(p)) {
@@ -8221,8 +8064,6 @@
rq = task_rq_lock(tsk, &flags);
- update_rq_clock(rq);
-
running = task_current(rq, tsk);
on_rq = tsk->se.on_rq;
@@ -8241,7 +8082,7 @@
if (unlikely(running))
tsk->sched_class->set_curr_task(rq);
if (on_rq)
- enqueue_task(rq, tsk, 0, false);
+ enqueue_task(rq, tsk, 0);
task_rq_unlock(rq, &flags);
}
@@ -9055,43 +8896,32 @@
#ifndef CONFIG_SMP
-int rcu_expedited_torture_stats(char *page)
-{
- return 0;
-}
-EXPORT_SYMBOL_GPL(rcu_expedited_torture_stats);
-
void synchronize_sched_expedited(void)
{
+ barrier();
}
EXPORT_SYMBOL_GPL(synchronize_sched_expedited);
#else /* #ifndef CONFIG_SMP */
-static DEFINE_PER_CPU(struct migration_req, rcu_migration_req);
-static DEFINE_MUTEX(rcu_sched_expedited_mutex);
+static atomic_t synchronize_sched_expedited_count = ATOMIC_INIT(0);
-#define RCU_EXPEDITED_STATE_POST -2
-#define RCU_EXPEDITED_STATE_IDLE -1
-
-static int rcu_expedited_state = RCU_EXPEDITED_STATE_IDLE;
-
-int rcu_expedited_torture_stats(char *page)
+static int synchronize_sched_expedited_cpu_stop(void *data)
{
- int cnt = 0;
- int cpu;
-
- cnt += sprintf(&page[cnt], "state: %d /", rcu_expedited_state);
- for_each_online_cpu(cpu) {
- cnt += sprintf(&page[cnt], " %d:%d",
- cpu, per_cpu(rcu_migration_req, cpu).dest_cpu);
- }
- cnt += sprintf(&page[cnt], "\n");
- return cnt;
+ /*
+ * There must be a full memory barrier on each affected CPU
+ * between the time that try_stop_cpus() is called and the
+ * time that it returns.
+ *
+ * In the current initial implementation of cpu_stop, the
+ * above condition is already met when the control reaches
+ * this point and the following smp_mb() is not strictly
+ * necessary. Do smp_mb() anyway for documentation and
+ * robustness against future implementation changes.
+ */
+ smp_mb(); /* See above comment block. */
+ return 0;
}
-EXPORT_SYMBOL_GPL(rcu_expedited_torture_stats);
-
-static long synchronize_sched_expedited_count;
/*
* Wait for an rcu-sched grace period to elapse, but use "big hammer"
@@ -9105,18 +8935,14 @@
*/
void synchronize_sched_expedited(void)
{
- int cpu;
- unsigned long flags;
- bool need_full_sync = 0;
- struct rq *rq;
- struct migration_req *req;
- long snap;
- int trycount = 0;
+ int snap, trycount = 0;
smp_mb(); /* ensure prior mod happens before capturing snap. */
- snap = ACCESS_ONCE(synchronize_sched_expedited_count) + 1;
+ snap = atomic_read(&synchronize_sched_expedited_count) + 1;
get_online_cpus();
- while (!mutex_trylock(&rcu_sched_expedited_mutex)) {
+ while (try_stop_cpus(cpu_online_mask,
+ synchronize_sched_expedited_cpu_stop,
+ NULL) == -EAGAIN) {
put_online_cpus();
if (trycount++ < 10)
udelay(trycount * num_online_cpus());
@@ -9124,41 +8950,15 @@
synchronize_sched();
return;
}
- if (ACCESS_ONCE(synchronize_sched_expedited_count) - snap > 0) {
+ if (atomic_read(&synchronize_sched_expedited_count) - snap > 0) {
smp_mb(); /* ensure test happens before caller kfree */
return;
}
get_online_cpus();
}
- rcu_expedited_state = RCU_EXPEDITED_STATE_POST;
- for_each_online_cpu(cpu) {
- rq = cpu_rq(cpu);
- req = &per_cpu(rcu_migration_req, cpu);
- init_completion(&req->done);
- req->task = NULL;
- req->dest_cpu = RCU_MIGRATION_NEED_QS;
- raw_spin_lock_irqsave(&rq->lock, flags);
- list_add(&req->list, &rq->migration_queue);
- raw_spin_unlock_irqrestore(&rq->lock, flags);
- wake_up_process(rq->migration_thread);
- }
- for_each_online_cpu(cpu) {
- rcu_expedited_state = cpu;
- req = &per_cpu(rcu_migration_req, cpu);
- rq = cpu_rq(cpu);
- wait_for_completion(&req->done);
- raw_spin_lock_irqsave(&rq->lock, flags);
- if (unlikely(req->dest_cpu == RCU_MIGRATION_MUST_SYNC))
- need_full_sync = 1;
- req->dest_cpu = RCU_MIGRATION_IDLE;
- raw_spin_unlock_irqrestore(&rq->lock, flags);
- }
- rcu_expedited_state = RCU_EXPEDITED_STATE_IDLE;
- synchronize_sched_expedited_count++;
- mutex_unlock(&rcu_sched_expedited_mutex);
+ atomic_inc(&synchronize_sched_expedited_count);
+ smp_mb__after_atomic_inc(); /* ensure post-GP actions seen after GP. */
put_online_cpus();
- if (need_full_sync)
- synchronize_sched();
}
EXPORT_SYMBOL_GPL(synchronize_sched_expedited);
diff --git a/kernel/sched_debug.c b/kernel/sched_debug.c
index 19be00b..87a330a 100644
--- a/kernel/sched_debug.c
+++ b/kernel/sched_debug.c
@@ -70,16 +70,16 @@
PN(se->vruntime);
PN(se->sum_exec_runtime);
#ifdef CONFIG_SCHEDSTATS
- PN(se->wait_start);
- PN(se->sleep_start);
- PN(se->block_start);
- PN(se->sleep_max);
- PN(se->block_max);
- PN(se->exec_max);
- PN(se->slice_max);
- PN(se->wait_max);
- PN(se->wait_sum);
- P(se->wait_count);
+ PN(se->statistics.wait_start);
+ PN(se->statistics.sleep_start);
+ PN(se->statistics.block_start);
+ PN(se->statistics.sleep_max);
+ PN(se->statistics.block_max);
+ PN(se->statistics.exec_max);
+ PN(se->statistics.slice_max);
+ PN(se->statistics.wait_max);
+ PN(se->statistics.wait_sum);
+ P(se->statistics.wait_count);
#endif
P(se->load.weight);
#undef PN
@@ -104,7 +104,7 @@
SEQ_printf(m, "%9Ld.%06ld %9Ld.%06ld %9Ld.%06ld",
SPLIT_NS(p->se.vruntime),
SPLIT_NS(p->se.sum_exec_runtime),
- SPLIT_NS(p->se.sum_sleep_runtime));
+ SPLIT_NS(p->se.statistics.sum_sleep_runtime));
#else
SEQ_printf(m, "%15Ld %15Ld %15Ld.%06ld %15Ld.%06ld %15Ld.%06ld",
0LL, 0LL, 0LL, 0L, 0LL, 0L, 0LL, 0L);
@@ -175,11 +175,6 @@
task_group_path(tg, path, sizeof(path));
SEQ_printf(m, "\ncfs_rq[%d]:%s\n", cpu, path);
-#elif defined(CONFIG_USER_SCHED) && defined(CONFIG_FAIR_GROUP_SCHED)
- {
- uid_t uid = cfs_rq->tg->uid;
- SEQ_printf(m, "\ncfs_rq[%d] for UID: %u\n", cpu, uid);
- }
#else
SEQ_printf(m, "\ncfs_rq[%d]:\n", cpu);
#endif
@@ -409,40 +404,38 @@
PN(se.exec_start);
PN(se.vruntime);
PN(se.sum_exec_runtime);
- PN(se.avg_overlap);
- PN(se.avg_wakeup);
nr_switches = p->nvcsw + p->nivcsw;
#ifdef CONFIG_SCHEDSTATS
- PN(se.wait_start);
- PN(se.sleep_start);
- PN(se.block_start);
- PN(se.sleep_max);
- PN(se.block_max);
- PN(se.exec_max);
- PN(se.slice_max);
- PN(se.wait_max);
- PN(se.wait_sum);
- P(se.wait_count);
- PN(se.iowait_sum);
- P(se.iowait_count);
+ PN(se.statistics.wait_start);
+ PN(se.statistics.sleep_start);
+ PN(se.statistics.block_start);
+ PN(se.statistics.sleep_max);
+ PN(se.statistics.block_max);
+ PN(se.statistics.exec_max);
+ PN(se.statistics.slice_max);
+ PN(se.statistics.wait_max);
+ PN(se.statistics.wait_sum);
+ P(se.statistics.wait_count);
+ PN(se.statistics.iowait_sum);
+ P(se.statistics.iowait_count);
P(sched_info.bkl_count);
P(se.nr_migrations);
- P(se.nr_migrations_cold);
- P(se.nr_failed_migrations_affine);
- P(se.nr_failed_migrations_running);
- P(se.nr_failed_migrations_hot);
- P(se.nr_forced_migrations);
- P(se.nr_wakeups);
- P(se.nr_wakeups_sync);
- P(se.nr_wakeups_migrate);
- P(se.nr_wakeups_local);
- P(se.nr_wakeups_remote);
- P(se.nr_wakeups_affine);
- P(se.nr_wakeups_affine_attempts);
- P(se.nr_wakeups_passive);
- P(se.nr_wakeups_idle);
+ P(se.statistics.nr_migrations_cold);
+ P(se.statistics.nr_failed_migrations_affine);
+ P(se.statistics.nr_failed_migrations_running);
+ P(se.statistics.nr_failed_migrations_hot);
+ P(se.statistics.nr_forced_migrations);
+ P(se.statistics.nr_wakeups);
+ P(se.statistics.nr_wakeups_sync);
+ P(se.statistics.nr_wakeups_migrate);
+ P(se.statistics.nr_wakeups_local);
+ P(se.statistics.nr_wakeups_remote);
+ P(se.statistics.nr_wakeups_affine);
+ P(se.statistics.nr_wakeups_affine_attempts);
+ P(se.statistics.nr_wakeups_passive);
+ P(se.statistics.nr_wakeups_idle);
{
u64 avg_atom, avg_per_cpu;
@@ -493,31 +486,6 @@
void proc_sched_set_task(struct task_struct *p)
{
#ifdef CONFIG_SCHEDSTATS
- p->se.wait_max = 0;
- p->se.wait_sum = 0;
- p->se.wait_count = 0;
- p->se.iowait_sum = 0;
- p->se.iowait_count = 0;
- p->se.sleep_max = 0;
- p->se.sum_sleep_runtime = 0;
- p->se.block_max = 0;
- p->se.exec_max = 0;
- p->se.slice_max = 0;
- p->se.nr_migrations = 0;
- p->se.nr_migrations_cold = 0;
- p->se.nr_failed_migrations_affine = 0;
- p->se.nr_failed_migrations_running = 0;
- p->se.nr_failed_migrations_hot = 0;
- p->se.nr_forced_migrations = 0;
- p->se.nr_wakeups = 0;
- p->se.nr_wakeups_sync = 0;
- p->se.nr_wakeups_migrate = 0;
- p->se.nr_wakeups_local = 0;
- p->se.nr_wakeups_remote = 0;
- p->se.nr_wakeups_affine = 0;
- p->se.nr_wakeups_affine_attempts = 0;
- p->se.nr_wakeups_passive = 0;
- p->se.nr_wakeups_idle = 0;
- p->sched_info.bkl_count = 0;
+ memset(&p->se.statistics, 0, sizeof(p->se.statistics));
#endif
}
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 5a5ea2c..217e4a9 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -35,8 +35,8 @@
* (to see the precise effective timeslice length of your workload,
* run vmstat and monitor the context-switches (cs) field)
*/
-unsigned int sysctl_sched_latency = 5000000ULL;
-unsigned int normalized_sysctl_sched_latency = 5000000ULL;
+unsigned int sysctl_sched_latency = 6000000ULL;
+unsigned int normalized_sysctl_sched_latency = 6000000ULL;
/*
* The initial- and re-scaling of tunables is configurable
@@ -52,15 +52,15 @@
/*
* Minimal preemption granularity for CPU-bound tasks:
- * (default: 1 msec * (1 + ilog(ncpus)), units: nanoseconds)
+ * (default: 2 msec * (1 + ilog(ncpus)), units: nanoseconds)
*/
-unsigned int sysctl_sched_min_granularity = 1000000ULL;
-unsigned int normalized_sysctl_sched_min_granularity = 1000000ULL;
+unsigned int sysctl_sched_min_granularity = 2000000ULL;
+unsigned int normalized_sysctl_sched_min_granularity = 2000000ULL;
/*
* is kept at sysctl_sched_latency / sysctl_sched_min_granularity
*/
-static unsigned int sched_nr_latency = 5;
+static unsigned int sched_nr_latency = 3;
/*
* After fork, child runs first. If set to 0 (default) then
@@ -505,7 +505,8 @@
{
unsigned long delta_exec_weighted;
- schedstat_set(curr->exec_max, max((u64)delta_exec, curr->exec_max));
+ schedstat_set(curr->statistics.exec_max,
+ max((u64)delta_exec, curr->statistics.exec_max));
curr->sum_exec_runtime += delta_exec;
schedstat_add(cfs_rq, exec_clock, delta_exec);
@@ -548,7 +549,7 @@
static inline void
update_stats_wait_start(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
- schedstat_set(se->wait_start, rq_of(cfs_rq)->clock);
+ schedstat_set(se->statistics.wait_start, rq_of(cfs_rq)->clock);
}
/*
@@ -567,18 +568,18 @@
static void
update_stats_wait_end(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
- schedstat_set(se->wait_max, max(se->wait_max,
- rq_of(cfs_rq)->clock - se->wait_start));
- schedstat_set(se->wait_count, se->wait_count + 1);
- schedstat_set(se->wait_sum, se->wait_sum +
- rq_of(cfs_rq)->clock - se->wait_start);
+ schedstat_set(se->statistics.wait_max, max(se->statistics.wait_max,
+ rq_of(cfs_rq)->clock - se->statistics.wait_start));
+ schedstat_set(se->statistics.wait_count, se->statistics.wait_count + 1);
+ schedstat_set(se->statistics.wait_sum, se->statistics.wait_sum +
+ rq_of(cfs_rq)->clock - se->statistics.wait_start);
#ifdef CONFIG_SCHEDSTATS
if (entity_is_task(se)) {
trace_sched_stat_wait(task_of(se),
- rq_of(cfs_rq)->clock - se->wait_start);
+ rq_of(cfs_rq)->clock - se->statistics.wait_start);
}
#endif
- schedstat_set(se->wait_start, 0);
+ schedstat_set(se->statistics.wait_start, 0);
}
static inline void
@@ -657,39 +658,39 @@
if (entity_is_task(se))
tsk = task_of(se);
- if (se->sleep_start) {
- u64 delta = rq_of(cfs_rq)->clock - se->sleep_start;
+ if (se->statistics.sleep_start) {
+ u64 delta = rq_of(cfs_rq)->clock - se->statistics.sleep_start;
if ((s64)delta < 0)
delta = 0;
- if (unlikely(delta > se->sleep_max))
- se->sleep_max = delta;
+ if (unlikely(delta > se->statistics.sleep_max))
+ se->statistics.sleep_max = delta;
- se->sleep_start = 0;
- se->sum_sleep_runtime += delta;
+ se->statistics.sleep_start = 0;
+ se->statistics.sum_sleep_runtime += delta;
if (tsk) {
account_scheduler_latency(tsk, delta >> 10, 1);
trace_sched_stat_sleep(tsk, delta);
}
}
- if (se->block_start) {
- u64 delta = rq_of(cfs_rq)->clock - se->block_start;
+ if (se->statistics.block_start) {
+ u64 delta = rq_of(cfs_rq)->clock - se->statistics.block_start;
if ((s64)delta < 0)
delta = 0;
- if (unlikely(delta > se->block_max))
- se->block_max = delta;
+ if (unlikely(delta > se->statistics.block_max))
+ se->statistics.block_max = delta;
- se->block_start = 0;
- se->sum_sleep_runtime += delta;
+ se->statistics.block_start = 0;
+ se->statistics.sum_sleep_runtime += delta;
if (tsk) {
if (tsk->in_iowait) {
- se->iowait_sum += delta;
- se->iowait_count++;
+ se->statistics.iowait_sum += delta;
+ se->statistics.iowait_count++;
trace_sched_stat_iowait(tsk, delta);
}
@@ -737,20 +738,10 @@
vruntime += sched_vslice(cfs_rq, se);
/* sleeps up to a single latency don't count. */
- if (!initial && sched_feat(FAIR_SLEEPERS)) {
+ if (!initial) {
unsigned long thresh = sysctl_sched_latency;
/*
- * Convert the sleeper threshold into virtual time.
- * SCHED_IDLE is a special sub-class. We care about
- * fairness only relative to other SCHED_IDLE tasks,
- * all of which have the same weight.
- */
- if (sched_feat(NORMALIZED_SLEEPER) && (!entity_is_task(se) ||
- task_of(se)->policy != SCHED_IDLE))
- thresh = calc_delta_fair(thresh, se);
-
- /*
* Halve their sleep time's effect, to allow
* for a gentler effect of sleepers:
*/
@@ -766,9 +757,6 @@
se->vruntime = vruntime;
}
-#define ENQUEUE_WAKEUP 1
-#define ENQUEUE_MIGRATE 2
-
static void
enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
{
@@ -776,7 +764,7 @@
* Update the normalized vruntime before updating min_vruntime
* through callig update_curr().
*/
- if (!(flags & ENQUEUE_WAKEUP) || (flags & ENQUEUE_MIGRATE))
+ if (!(flags & ENQUEUE_WAKEUP) || (flags & ENQUEUE_WAKING))
se->vruntime += cfs_rq->min_vruntime;
/*
@@ -812,7 +800,7 @@
}
static void
-dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep)
+dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
{
/*
* Update run-time statistics of the 'current'.
@@ -820,15 +808,15 @@
update_curr(cfs_rq);
update_stats_dequeue(cfs_rq, se);
- if (sleep) {
+ if (flags & DEQUEUE_SLEEP) {
#ifdef CONFIG_SCHEDSTATS
if (entity_is_task(se)) {
struct task_struct *tsk = task_of(se);
if (tsk->state & TASK_INTERRUPTIBLE)
- se->sleep_start = rq_of(cfs_rq)->clock;
+ se->statistics.sleep_start = rq_of(cfs_rq)->clock;
if (tsk->state & TASK_UNINTERRUPTIBLE)
- se->block_start = rq_of(cfs_rq)->clock;
+ se->statistics.block_start = rq_of(cfs_rq)->clock;
}
#endif
}
@@ -845,7 +833,7 @@
* update can refer to the ->curr item and we need to reflect this
* movement in our normalized position.
*/
- if (!sleep)
+ if (!(flags & DEQUEUE_SLEEP))
se->vruntime -= cfs_rq->min_vruntime;
}
@@ -912,7 +900,7 @@
* when there are only lesser-weight tasks around):
*/
if (rq_of(cfs_rq)->load.weight >= 2*se->load.weight) {
- se->slice_max = max(se->slice_max,
+ se->statistics.slice_max = max(se->statistics.slice_max,
se->sum_exec_runtime - se->prev_sum_exec_runtime);
}
#endif
@@ -1054,16 +1042,10 @@
* then put the task into the rbtree:
*/
static void
-enqueue_task_fair(struct rq *rq, struct task_struct *p, int wakeup, bool head)
+enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags)
{
struct cfs_rq *cfs_rq;
struct sched_entity *se = &p->se;
- int flags = 0;
-
- if (wakeup)
- flags |= ENQUEUE_WAKEUP;
- if (p->state == TASK_WAKING)
- flags |= ENQUEUE_MIGRATE;
for_each_sched_entity(se) {
if (se->on_rq)
@@ -1081,18 +1063,18 @@
* decreased. We remove the task from the rbtree and
* update the fair scheduling stats:
*/
-static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int sleep)
+static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int flags)
{
struct cfs_rq *cfs_rq;
struct sched_entity *se = &p->se;
for_each_sched_entity(se) {
cfs_rq = cfs_rq_of(se);
- dequeue_entity(cfs_rq, se, sleep);
+ dequeue_entity(cfs_rq, se, flags);
/* Don't dequeue parent if it has other entities besides us */
if (cfs_rq->load.weight)
break;
- sleep = 1;
+ flags |= DEQUEUE_SLEEP;
}
hrtick_update(rq);
@@ -1240,7 +1222,6 @@
static int wake_affine(struct sched_domain *sd, struct task_struct *p, int sync)
{
- struct task_struct *curr = current;
unsigned long this_load, load;
int idx, this_cpu, prev_cpu;
unsigned long tl_per_task;
@@ -1255,18 +1236,6 @@
load = source_load(prev_cpu, idx);
this_load = target_load(this_cpu, idx);
- if (sync) {
- if (sched_feat(SYNC_LESS) &&
- (curr->se.avg_overlap > sysctl_sched_migration_cost ||
- p->se.avg_overlap > sysctl_sched_migration_cost))
- sync = 0;
- } else {
- if (sched_feat(SYNC_MORE) &&
- (curr->se.avg_overlap < sysctl_sched_migration_cost &&
- p->se.avg_overlap < sysctl_sched_migration_cost))
- sync = 1;
- }
-
/*
* If sync wakeup then subtract the (maximum possible)
* effect of the currently running task from the load
@@ -1306,7 +1275,7 @@
if (sync && balanced)
return 1;
- schedstat_inc(p, se.nr_wakeups_affine_attempts);
+ schedstat_inc(p, se.statistics.nr_wakeups_affine_attempts);
tl_per_task = cpu_avg_load_per_task(this_cpu);
if (balanced ||
@@ -1318,7 +1287,7 @@
* there is no bad imbalance.
*/
schedstat_inc(sd, ttwu_move_affine);
- schedstat_inc(p, se.nr_wakeups_affine);
+ schedstat_inc(p, se.statistics.nr_wakeups_affine);
return 1;
}
@@ -1406,29 +1375,48 @@
/*
* Try and locate an idle CPU in the sched_domain.
*/
-static int
-select_idle_sibling(struct task_struct *p, struct sched_domain *sd, int target)
+static int select_idle_sibling(struct task_struct *p, int target)
{
int cpu = smp_processor_id();
int prev_cpu = task_cpu(p);
+ struct sched_domain *sd;
int i;
/*
- * If this domain spans both cpu and prev_cpu (see the SD_WAKE_AFFINE
- * test in select_task_rq_fair) and the prev_cpu is idle then that's
- * always a better target than the current cpu.
+ * If the task is going to be woken-up on this cpu and if it is
+ * already idle, then it is the right target.
*/
- if (target == cpu && !cpu_rq(prev_cpu)->cfs.nr_running)
+ if (target == cpu && idle_cpu(cpu))
+ return cpu;
+
+ /*
+ * If the task is going to be woken-up on the cpu where it previously
+ * ran and if it is currently idle, then it the right target.
+ */
+ if (target == prev_cpu && idle_cpu(prev_cpu))
return prev_cpu;
/*
- * Otherwise, iterate the domain and find an elegible idle cpu.
+ * Otherwise, iterate the domains and find an elegible idle cpu.
*/
- for_each_cpu_and(i, sched_domain_span(sd), &p->cpus_allowed) {
- if (!cpu_rq(i)->cfs.nr_running) {
- target = i;
+ for_each_domain(target, sd) {
+ if (!(sd->flags & SD_SHARE_PKG_RESOURCES))
break;
+
+ for_each_cpu_and(i, sched_domain_span(sd), &p->cpus_allowed) {
+ if (idle_cpu(i)) {
+ target = i;
+ break;
+ }
}
+
+ /*
+ * Lets stop looking for an idle sibling when we reached
+ * the domain that spans the current cpu and prev_cpu.
+ */
+ if (cpumask_test_cpu(cpu, sched_domain_span(sd)) &&
+ cpumask_test_cpu(prev_cpu, sched_domain_span(sd)))
+ break;
}
return target;
@@ -1445,7 +1433,8 @@
*
* preempt must be disabled.
*/
-static int select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flags)
+static int
+select_task_rq_fair(struct rq *rq, struct task_struct *p, int sd_flag, int wake_flags)
{
struct sched_domain *tmp, *affine_sd = NULL, *sd = NULL;
int cpu = smp_processor_id();
@@ -1456,8 +1445,7 @@
int sync = wake_flags & WF_SYNC;
if (sd_flag & SD_BALANCE_WAKE) {
- if (sched_feat(AFFINE_WAKEUPS) &&
- cpumask_test_cpu(cpu, &p->cpus_allowed))
+ if (cpumask_test_cpu(cpu, &p->cpus_allowed))
want_affine = 1;
new_cpu = prev_cpu;
}
@@ -1491,34 +1479,13 @@
}
/*
- * While iterating the domains looking for a spanning
- * WAKE_AFFINE domain, adjust the affine target to any idle cpu
- * in cache sharing domains along the way.
+ * If both cpu and prev_cpu are part of this domain,
+ * cpu is a valid SD_WAKE_AFFINE target.
*/
- if (want_affine) {
- int target = -1;
-
- /*
- * If both cpu and prev_cpu are part of this domain,
- * cpu is a valid SD_WAKE_AFFINE target.
- */
- if (cpumask_test_cpu(prev_cpu, sched_domain_span(tmp)))
- target = cpu;
-
- /*
- * If there's an idle sibling in this domain, make that
- * the wake_affine target instead of the current cpu.
- */
- if (tmp->flags & SD_SHARE_PKG_RESOURCES)
- target = select_idle_sibling(p, tmp, target);
-
- if (target >= 0) {
- if (tmp->flags & SD_WAKE_AFFINE) {
- affine_sd = tmp;
- want_affine = 0;
- }
- cpu = target;
- }
+ if (want_affine && (tmp->flags & SD_WAKE_AFFINE) &&
+ cpumask_test_cpu(prev_cpu, sched_domain_span(tmp))) {
+ affine_sd = tmp;
+ want_affine = 0;
}
if (!want_sd && !want_affine)
@@ -1531,22 +1498,29 @@
sd = tmp;
}
+#ifdef CONFIG_FAIR_GROUP_SCHED
if (sched_feat(LB_SHARES_UPDATE)) {
/*
* Pick the largest domain to update shares over
*/
tmp = sd;
- if (affine_sd && (!tmp ||
- cpumask_weight(sched_domain_span(affine_sd)) >
- cpumask_weight(sched_domain_span(sd))))
+ if (affine_sd && (!tmp || affine_sd->span_weight > sd->span_weight))
tmp = affine_sd;
- if (tmp)
+ if (tmp) {
+ raw_spin_unlock(&rq->lock);
update_shares(tmp);
+ raw_spin_lock(&rq->lock);
+ }
}
+#endif
- if (affine_sd && wake_affine(affine_sd, p, sync))
- return cpu;
+ if (affine_sd) {
+ if (cpu == prev_cpu || wake_affine(affine_sd, p, sync))
+ return select_idle_sibling(p, cpu);
+ else
+ return select_idle_sibling(p, prev_cpu);
+ }
while (sd) {
int load_idx = sd->forkexec_idx;
@@ -1576,10 +1550,10 @@
/* Now try balancing at a lower domain level of new_cpu */
cpu = new_cpu;
- weight = cpumask_weight(sched_domain_span(sd));
+ weight = sd->span_weight;
sd = NULL;
for_each_domain(cpu, tmp) {
- if (weight <= cpumask_weight(sched_domain_span(tmp)))
+ if (weight <= tmp->span_weight)
break;
if (tmp->flags & sd_flag)
sd = tmp;
@@ -1591,63 +1565,26 @@
}
#endif /* CONFIG_SMP */
-/*
- * Adaptive granularity
- *
- * se->avg_wakeup gives the average time a task runs until it does a wakeup,
- * with the limit of wakeup_gran -- when it never does a wakeup.
- *
- * So the smaller avg_wakeup is the faster we want this task to preempt,
- * but we don't want to treat the preemptee unfairly and therefore allow it
- * to run for at least the amount of time we'd like to run.
- *
- * NOTE: we use 2*avg_wakeup to increase the probability of actually doing one
- *
- * NOTE: we use *nr_running to scale with load, this nicely matches the
- * degrading latency on load.
- */
-static unsigned long
-adaptive_gran(struct sched_entity *curr, struct sched_entity *se)
-{
- u64 this_run = curr->sum_exec_runtime - curr->prev_sum_exec_runtime;
- u64 expected_wakeup = 2*se->avg_wakeup * cfs_rq_of(se)->nr_running;
- u64 gran = 0;
-
- if (this_run < expected_wakeup)
- gran = expected_wakeup - this_run;
-
- return min_t(s64, gran, sysctl_sched_wakeup_granularity);
-}
-
static unsigned long
wakeup_gran(struct sched_entity *curr, struct sched_entity *se)
{
unsigned long gran = sysctl_sched_wakeup_granularity;
- if (cfs_rq_of(curr)->curr && sched_feat(ADAPTIVE_GRAN))
- gran = adaptive_gran(curr, se);
-
/*
* Since its curr running now, convert the gran from real-time
* to virtual-time in his units.
+ *
+ * By using 'se' instead of 'curr' we penalize light tasks, so
+ * they get preempted easier. That is, if 'se' < 'curr' then
+ * the resulting gran will be larger, therefore penalizing the
+ * lighter, if otoh 'se' > 'curr' then the resulting gran will
+ * be smaller, again penalizing the lighter task.
+ *
+ * This is especially important for buddies when the leftmost
+ * task is higher priority than the buddy.
*/
- if (sched_feat(ASYM_GRAN)) {
- /*
- * By using 'se' instead of 'curr' we penalize light tasks, so
- * they get preempted easier. That is, if 'se' < 'curr' then
- * the resulting gran will be larger, therefore penalizing the
- * lighter, if otoh 'se' > 'curr' then the resulting gran will
- * be smaller, again penalizing the lighter task.
- *
- * This is especially important for buddies when the leftmost
- * task is higher priority than the buddy.
- */
- if (unlikely(se->load.weight != NICE_0_LOAD))
- gran = calc_delta_fair(gran, se);
- } else {
- if (unlikely(curr->load.weight != NICE_0_LOAD))
- gran = calc_delta_fair(gran, curr);
- }
+ if (unlikely(se->load.weight != NICE_0_LOAD))
+ gran = calc_delta_fair(gran, se);
return gran;
}
@@ -1705,7 +1642,6 @@
struct task_struct *curr = rq->curr;
struct sched_entity *se = &curr->se, *pse = &p->se;
struct cfs_rq *cfs_rq = task_cfs_rq(curr);
- int sync = wake_flags & WF_SYNC;
int scale = cfs_rq->nr_running >= sched_nr_latency;
if (unlikely(rt_prio(p->prio)))
@@ -1738,14 +1674,6 @@
if (unlikely(curr->policy == SCHED_IDLE))
goto preempt;
- if (sched_feat(WAKEUP_SYNC) && sync)
- goto preempt;
-
- if (sched_feat(WAKEUP_OVERLAP) &&
- se->avg_overlap < sysctl_sched_migration_cost &&
- pse->avg_overlap < sysctl_sched_migration_cost)
- goto preempt;
-
if (!sched_feat(WAKEUP_PREEMPT))
return;
@@ -1844,13 +1772,13 @@
* 3) are cache-hot on their current CPU.
*/
if (!cpumask_test_cpu(this_cpu, &p->cpus_allowed)) {
- schedstat_inc(p, se.nr_failed_migrations_affine);
+ schedstat_inc(p, se.statistics.nr_failed_migrations_affine);
return 0;
}
*all_pinned = 0;
if (task_running(rq, p)) {
- schedstat_inc(p, se.nr_failed_migrations_running);
+ schedstat_inc(p, se.statistics.nr_failed_migrations_running);
return 0;
}
@@ -1866,14 +1794,14 @@
#ifdef CONFIG_SCHEDSTATS
if (tsk_cache_hot) {
schedstat_inc(sd, lb_hot_gained[idle]);
- schedstat_inc(p, se.nr_forced_migrations);
+ schedstat_inc(p, se.statistics.nr_forced_migrations);
}
#endif
return 1;
}
if (tsk_cache_hot) {
- schedstat_inc(p, se.nr_failed_migrations_hot);
+ schedstat_inc(p, se.statistics.nr_failed_migrations_hot);
return 0;
}
return 1;
@@ -2311,7 +2239,7 @@
unsigned long default_scale_smt_power(struct sched_domain *sd, int cpu)
{
- unsigned long weight = cpumask_weight(sched_domain_span(sd));
+ unsigned long weight = sd->span_weight;
unsigned long smt_gain = sd->smt_gain;
smt_gain /= weight;
@@ -2344,7 +2272,7 @@
static void update_cpu_power(struct sched_domain *sd, int cpu)
{
- unsigned long weight = cpumask_weight(sched_domain_span(sd));
+ unsigned long weight = sd->span_weight;
unsigned long power = SCHED_LOAD_SCALE;
struct sched_group *sdg = sd->groups;
@@ -2870,6 +2798,8 @@
return unlikely(sd->nr_balance_failed > sd->cache_nice_tries+2);
}
+static int active_load_balance_cpu_stop(void *data);
+
/*
* Check this_cpu to ensure it is balanced within domain. Attempt to move
* tasks if there is an imbalance.
@@ -2959,8 +2889,9 @@
if (need_active_balance(sd, sd_idle, idle)) {
raw_spin_lock_irqsave(&busiest->lock, flags);
- /* don't kick the migration_thread, if the curr
- * task on busiest cpu can't be moved to this_cpu
+ /* don't kick the active_load_balance_cpu_stop,
+ * if the curr task on busiest cpu can't be
+ * moved to this_cpu
*/
if (!cpumask_test_cpu(this_cpu,
&busiest->curr->cpus_allowed)) {
@@ -2970,14 +2901,22 @@
goto out_one_pinned;
}
+ /*
+ * ->active_balance synchronizes accesses to
+ * ->active_balance_work. Once set, it's cleared
+ * only after active load balance is finished.
+ */
if (!busiest->active_balance) {
busiest->active_balance = 1;
busiest->push_cpu = this_cpu;
active_balance = 1;
}
raw_spin_unlock_irqrestore(&busiest->lock, flags);
+
if (active_balance)
- wake_up_process(busiest->migration_thread);
+ stop_one_cpu_nowait(cpu_of(busiest),
+ active_load_balance_cpu_stop, busiest,
+ &busiest->active_balance_work);
/*
* We've kicked active balancing, reset the failure
@@ -3084,24 +3023,29 @@
}
/*
- * active_load_balance is run by migration threads. It pushes running tasks
- * off the busiest CPU onto idle CPUs. It requires at least 1 task to be
- * running on each physical CPU where possible, and avoids physical /
- * logical imbalances.
- *
- * Called with busiest_rq locked.
+ * active_load_balance_cpu_stop is run by cpu stopper. It pushes
+ * running tasks off the busiest CPU onto idle CPUs. It requires at
+ * least 1 task to be running on each physical CPU where possible, and
+ * avoids physical / logical imbalances.
*/
-static void active_load_balance(struct rq *busiest_rq, int busiest_cpu)
+static int active_load_balance_cpu_stop(void *data)
{
+ struct rq *busiest_rq = data;
+ int busiest_cpu = cpu_of(busiest_rq);
int target_cpu = busiest_rq->push_cpu;
+ struct rq *target_rq = cpu_rq(target_cpu);
struct sched_domain *sd;
- struct rq *target_rq;
+
+ raw_spin_lock_irq(&busiest_rq->lock);
+
+ /* make sure the requested cpu hasn't gone down in the meantime */
+ if (unlikely(busiest_cpu != smp_processor_id() ||
+ !busiest_rq->active_balance))
+ goto out_unlock;
/* Is there any task to move? */
if (busiest_rq->nr_running <= 1)
- return;
-
- target_rq = cpu_rq(target_cpu);
+ goto out_unlock;
/*
* This condition is "impossible", if it occurs
@@ -3112,8 +3056,6 @@
/* move a task from busiest_rq to target_rq */
double_lock_balance(busiest_rq, target_rq);
- update_rq_clock(busiest_rq);
- update_rq_clock(target_rq);
/* Search for an sd spanning us and the target CPU. */
for_each_domain(target_cpu, sd) {
@@ -3132,6 +3074,10 @@
schedstat_inc(sd, alb_failed);
}
double_unlock_balance(busiest_rq, target_rq);
+out_unlock:
+ busiest_rq->active_balance = 0;
+ raw_spin_unlock_irq(&busiest_rq->lock);
+ return 0;
}
#ifdef CONFIG_NO_HZ
diff --git a/kernel/sched_features.h b/kernel/sched_features.h
index d5059fd..83c66e8 100644
--- a/kernel/sched_features.h
+++ b/kernel/sched_features.h
@@ -1,11 +1,4 @@
/*
- * Disregards a certain amount of sleep time (sched_latency_ns) and
- * considers the task to be running during that period. This gives it
- * a service deficit on wakeup, allowing it to run sooner.
- */
-SCHED_FEAT(FAIR_SLEEPERS, 1)
-
-/*
* Only give sleepers 50% of their service deficit. This allows
* them to run sooner, but does not allow tons of sleepers to
* rip the spread apart.
@@ -13,13 +6,6 @@
SCHED_FEAT(GENTLE_FAIR_SLEEPERS, 1)
/*
- * By not normalizing the sleep time, heavy tasks get an effective
- * longer period, and lighter task an effective shorter period they
- * are considered running.
- */
-SCHED_FEAT(NORMALIZED_SLEEPER, 0)
-
-/*
* Place new tasks ahead so that they do not starve already running
* tasks
*/
@@ -31,37 +17,6 @@
SCHED_FEAT(WAKEUP_PREEMPT, 1)
/*
- * Compute wakeup_gran based on task behaviour, clipped to
- * [0, sched_wakeup_gran_ns]
- */
-SCHED_FEAT(ADAPTIVE_GRAN, 1)
-
-/*
- * When converting the wakeup granularity to virtual time, do it such
- * that heavier tasks preempting a lighter task have an edge.
- */
-SCHED_FEAT(ASYM_GRAN, 1)
-
-/*
- * Always wakeup-preempt SYNC wakeups, see SYNC_WAKEUPS.
- */
-SCHED_FEAT(WAKEUP_SYNC, 0)
-
-/*
- * Wakeup preempt based on task behaviour. Tasks that do not overlap
- * don't get preempted.
- */
-SCHED_FEAT(WAKEUP_OVERLAP, 0)
-
-/*
- * Use the SYNC wakeup hint, pipes and the likes use this to indicate
- * the remote end is likely to consume the data we just wrote, and
- * therefore has cache benefit from being placed on the same cpu, see
- * also AFFINE_WAKEUPS.
- */
-SCHED_FEAT(SYNC_WAKEUPS, 1)
-
-/*
* Based on load and program behaviour, see if it makes sense to place
* a newly woken task on the same cpu as the task that woke it --
* improve cache locality. Typically used with SYNC wakeups as
@@ -70,16 +25,6 @@
SCHED_FEAT(AFFINE_WAKEUPS, 1)
/*
- * Weaken SYNC hint based on overlap
- */
-SCHED_FEAT(SYNC_LESS, 1)
-
-/*
- * Add SYNC hint based on overlap
- */
-SCHED_FEAT(SYNC_MORE, 0)
-
-/*
* Prefer to schedule the task we woke last (assuming it failed
* wakeup-preemption), since its likely going to consume data we
* touched, increases cache locality.
diff --git a/kernel/sched_idletask.c b/kernel/sched_idletask.c
index a8a6d8a..9fa0f40 100644
--- a/kernel/sched_idletask.c
+++ b/kernel/sched_idletask.c
@@ -6,7 +6,8 @@
*/
#ifdef CONFIG_SMP
-static int select_task_rq_idle(struct task_struct *p, int sd_flag, int flags)
+static int
+select_task_rq_idle(struct rq *rq, struct task_struct *p, int sd_flag, int flags)
{
return task_cpu(p); /* IDLE tasks as never migrated */
}
@@ -22,8 +23,7 @@
static struct task_struct *pick_next_task_idle(struct rq *rq)
{
schedstat_inc(rq, sched_goidle);
- /* adjust the active tasks as we might go into a long sleep */
- calc_load_account_active(rq);
+ calc_load_account_idle(rq);
return rq->idle;
}
@@ -32,7 +32,7 @@
* message if some code attempts to do it:
*/
static void
-dequeue_task_idle(struct rq *rq, struct task_struct *p, int sleep)
+dequeue_task_idle(struct rq *rq, struct task_struct *p, int flags)
{
raw_spin_unlock_irq(&rq->lock);
printk(KERN_ERR "bad: scheduling from the idle thread!\n");
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index b5b920a..8afb953 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -613,7 +613,7 @@
if (unlikely((s64)delta_exec < 0))
delta_exec = 0;
- schedstat_set(curr->se.exec_max, max(curr->se.exec_max, delta_exec));
+ schedstat_set(curr->se.statistics.exec_max, max(curr->se.statistics.exec_max, delta_exec));
curr->se.sum_exec_runtime += delta_exec;
account_group_exec_runtime(curr, delta_exec);
@@ -888,20 +888,20 @@
* Adding/removing a task to/from a priority array:
*/
static void
-enqueue_task_rt(struct rq *rq, struct task_struct *p, int wakeup, bool head)
+enqueue_task_rt(struct rq *rq, struct task_struct *p, int flags)
{
struct sched_rt_entity *rt_se = &p->rt;
- if (wakeup)
+ if (flags & ENQUEUE_WAKEUP)
rt_se->timeout = 0;
- enqueue_rt_entity(rt_se, head);
+ enqueue_rt_entity(rt_se, flags & ENQUEUE_HEAD);
if (!task_current(rq, p) && p->rt.nr_cpus_allowed > 1)
enqueue_pushable_task(rq, p);
}
-static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int sleep)
+static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int flags)
{
struct sched_rt_entity *rt_se = &p->rt;
@@ -948,10 +948,9 @@
#ifdef CONFIG_SMP
static int find_lowest_rq(struct task_struct *task);
-static int select_task_rq_rt(struct task_struct *p, int sd_flag, int flags)
+static int
+select_task_rq_rt(struct rq *rq, struct task_struct *p, int sd_flag, int flags)
{
- struct rq *rq = task_rq(p);
-
if (sd_flag != SD_BALANCE_WAKE)
return smp_processor_id();
diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
index 9bb9fb1..b4e7431 100644
--- a/kernel/stop_machine.c
+++ b/kernel/stop_machine.c
@@ -1,17 +1,384 @@
-/* Copyright 2008, 2005 Rusty Russell rusty@rustcorp.com.au IBM Corporation.
- * GPL v2 and any later version.
+/*
+ * kernel/stop_machine.c
+ *
+ * Copyright (C) 2008, 2005 IBM Corporation.
+ * Copyright (C) 2008, 2005 Rusty Russell rusty@rustcorp.com.au
+ * Copyright (C) 2010 SUSE Linux Products GmbH
+ * Copyright (C) 2010 Tejun Heo <tj@kernel.org>
+ *
+ * This file is released under the GPLv2 and any later version.
*/
+#include <linux/completion.h>
#include <linux/cpu.h>
-#include <linux/err.h>
+#include <linux/init.h>
#include <linux/kthread.h>
#include <linux/module.h>
+#include <linux/percpu.h>
#include <linux/sched.h>
#include <linux/stop_machine.h>
-#include <linux/syscalls.h>
#include <linux/interrupt.h>
+#include <linux/kallsyms.h>
#include <asm/atomic.h>
-#include <asm/uaccess.h>
+
+/*
+ * Structure to determine completion condition and record errors. May
+ * be shared by works on different cpus.
+ */
+struct cpu_stop_done {
+ atomic_t nr_todo; /* nr left to execute */
+ bool executed; /* actually executed? */
+ int ret; /* collected return value */
+ struct completion completion; /* fired if nr_todo reaches 0 */
+};
+
+/* the actual stopper, one per every possible cpu, enabled on online cpus */
+struct cpu_stopper {
+ spinlock_t lock;
+ struct list_head works; /* list of pending works */
+ struct task_struct *thread; /* stopper thread */
+ bool enabled; /* is this stopper enabled? */
+};
+
+static DEFINE_PER_CPU(struct cpu_stopper, cpu_stopper);
+
+static void cpu_stop_init_done(struct cpu_stop_done *done, unsigned int nr_todo)
+{
+ memset(done, 0, sizeof(*done));
+ atomic_set(&done->nr_todo, nr_todo);
+ init_completion(&done->completion);
+}
+
+/* signal completion unless @done is NULL */
+static void cpu_stop_signal_done(struct cpu_stop_done *done, bool executed)
+{
+ if (done) {
+ if (executed)
+ done->executed = true;
+ if (atomic_dec_and_test(&done->nr_todo))
+ complete(&done->completion);
+ }
+}
+
+/* queue @work to @stopper. if offline, @work is completed immediately */
+static void cpu_stop_queue_work(struct cpu_stopper *stopper,
+ struct cpu_stop_work *work)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&stopper->lock, flags);
+
+ if (stopper->enabled) {
+ list_add_tail(&work->list, &stopper->works);
+ wake_up_process(stopper->thread);
+ } else
+ cpu_stop_signal_done(work->done, false);
+
+ spin_unlock_irqrestore(&stopper->lock, flags);
+}
+
+/**
+ * stop_one_cpu - stop a cpu
+ * @cpu: cpu to stop
+ * @fn: function to execute
+ * @arg: argument to @fn
+ *
+ * Execute @fn(@arg) on @cpu. @fn is run in a process context with
+ * the highest priority preempting any task on the cpu and
+ * monopolizing it. This function returns after the execution is
+ * complete.
+ *
+ * This function doesn't guarantee @cpu stays online till @fn
+ * completes. If @cpu goes down in the middle, execution may happen
+ * partially or fully on different cpus. @fn should either be ready
+ * for that or the caller should ensure that @cpu stays online until
+ * this function completes.
+ *
+ * CONTEXT:
+ * Might sleep.
+ *
+ * RETURNS:
+ * -ENOENT if @fn(@arg) was not executed because @cpu was offline;
+ * otherwise, the return value of @fn.
+ */
+int stop_one_cpu(unsigned int cpu, cpu_stop_fn_t fn, void *arg)
+{
+ struct cpu_stop_done done;
+ struct cpu_stop_work work = { .fn = fn, .arg = arg, .done = &done };
+
+ cpu_stop_init_done(&done, 1);
+ cpu_stop_queue_work(&per_cpu(cpu_stopper, cpu), &work);
+ wait_for_completion(&done.completion);
+ return done.executed ? done.ret : -ENOENT;
+}
+
+/**
+ * stop_one_cpu_nowait - stop a cpu but don't wait for completion
+ * @cpu: cpu to stop
+ * @fn: function to execute
+ * @arg: argument to @fn
+ *
+ * Similar to stop_one_cpu() but doesn't wait for completion. The
+ * caller is responsible for ensuring @work_buf is currently unused
+ * and will remain untouched until stopper starts executing @fn.
+ *
+ * CONTEXT:
+ * Don't care.
+ */
+void stop_one_cpu_nowait(unsigned int cpu, cpu_stop_fn_t fn, void *arg,
+ struct cpu_stop_work *work_buf)
+{
+ *work_buf = (struct cpu_stop_work){ .fn = fn, .arg = arg, };
+ cpu_stop_queue_work(&per_cpu(cpu_stopper, cpu), work_buf);
+}
+
+/* static data for stop_cpus */
+static DEFINE_MUTEX(stop_cpus_mutex);
+static DEFINE_PER_CPU(struct cpu_stop_work, stop_cpus_work);
+
+int __stop_cpus(const struct cpumask *cpumask, cpu_stop_fn_t fn, void *arg)
+{
+ struct cpu_stop_work *work;
+ struct cpu_stop_done done;
+ unsigned int cpu;
+
+ /* initialize works and done */
+ for_each_cpu(cpu, cpumask) {
+ work = &per_cpu(stop_cpus_work, cpu);
+ work->fn = fn;
+ work->arg = arg;
+ work->done = &done;
+ }
+ cpu_stop_init_done(&done, cpumask_weight(cpumask));
+
+ /*
+ * Disable preemption while queueing to avoid getting
+ * preempted by a stopper which might wait for other stoppers
+ * to enter @fn which can lead to deadlock.
+ */
+ preempt_disable();
+ for_each_cpu(cpu, cpumask)
+ cpu_stop_queue_work(&per_cpu(cpu_stopper, cpu),
+ &per_cpu(stop_cpus_work, cpu));
+ preempt_enable();
+
+ wait_for_completion(&done.completion);
+ return done.executed ? done.ret : -ENOENT;
+}
+
+/**
+ * stop_cpus - stop multiple cpus
+ * @cpumask: cpus to stop
+ * @fn: function to execute
+ * @arg: argument to @fn
+ *
+ * Execute @fn(@arg) on online cpus in @cpumask. On each target cpu,
+ * @fn is run in a process context with the highest priority
+ * preempting any task on the cpu and monopolizing it. This function
+ * returns after all executions are complete.
+ *
+ * This function doesn't guarantee the cpus in @cpumask stay online
+ * till @fn completes. If some cpus go down in the middle, execution
+ * on the cpu may happen partially or fully on different cpus. @fn
+ * should either be ready for that or the caller should ensure that
+ * the cpus stay online until this function completes.
+ *
+ * All stop_cpus() calls are serialized making it safe for @fn to wait
+ * for all cpus to start executing it.
+ *
+ * CONTEXT:
+ * Might sleep.
+ *
+ * RETURNS:
+ * -ENOENT if @fn(@arg) was not executed at all because all cpus in
+ * @cpumask were offline; otherwise, 0 if all executions of @fn
+ * returned 0, any non zero return value if any returned non zero.
+ */
+int stop_cpus(const struct cpumask *cpumask, cpu_stop_fn_t fn, void *arg)
+{
+ int ret;
+
+ /* static works are used, process one request at a time */
+ mutex_lock(&stop_cpus_mutex);
+ ret = __stop_cpus(cpumask, fn, arg);
+ mutex_unlock(&stop_cpus_mutex);
+ return ret;
+}
+
+/**
+ * try_stop_cpus - try to stop multiple cpus
+ * @cpumask: cpus to stop
+ * @fn: function to execute
+ * @arg: argument to @fn
+ *
+ * Identical to stop_cpus() except that it fails with -EAGAIN if
+ * someone else is already using the facility.
+ *
+ * CONTEXT:
+ * Might sleep.
+ *
+ * RETURNS:
+ * -EAGAIN if someone else is already stopping cpus, -ENOENT if
+ * @fn(@arg) was not executed at all because all cpus in @cpumask were
+ * offline; otherwise, 0 if all executions of @fn returned 0, any non
+ * zero return value if any returned non zero.
+ */
+int try_stop_cpus(const struct cpumask *cpumask, cpu_stop_fn_t fn, void *arg)
+{
+ int ret;
+
+ /* static works are used, process one request at a time */
+ if (!mutex_trylock(&stop_cpus_mutex))
+ return -EAGAIN;
+ ret = __stop_cpus(cpumask, fn, arg);
+ mutex_unlock(&stop_cpus_mutex);
+ return ret;
+}
+
+static int cpu_stopper_thread(void *data)
+{
+ struct cpu_stopper *stopper = data;
+ struct cpu_stop_work *work;
+ int ret;
+
+repeat:
+ set_current_state(TASK_INTERRUPTIBLE); /* mb paired w/ kthread_stop */
+
+ if (kthread_should_stop()) {
+ __set_current_state(TASK_RUNNING);
+ return 0;
+ }
+
+ work = NULL;
+ spin_lock_irq(&stopper->lock);
+ if (!list_empty(&stopper->works)) {
+ work = list_first_entry(&stopper->works,
+ struct cpu_stop_work, list);
+ list_del_init(&work->list);
+ }
+ spin_unlock_irq(&stopper->lock);
+
+ if (work) {
+ cpu_stop_fn_t fn = work->fn;
+ void *arg = work->arg;
+ struct cpu_stop_done *done = work->done;
+ char ksym_buf[KSYM_NAME_LEN];
+
+ __set_current_state(TASK_RUNNING);
+
+ /* cpu stop callbacks are not allowed to sleep */
+ preempt_disable();
+
+ ret = fn(arg);
+ if (ret)
+ done->ret = ret;
+
+ /* restore preemption and check it's still balanced */
+ preempt_enable();
+ WARN_ONCE(preempt_count(),
+ "cpu_stop: %s(%p) leaked preempt count\n",
+ kallsyms_lookup((unsigned long)fn, NULL, NULL, NULL,
+ ksym_buf), arg);
+
+ cpu_stop_signal_done(done, true);
+ } else
+ schedule();
+
+ goto repeat;
+}
+
+/* manage stopper for a cpu, mostly lifted from sched migration thread mgmt */
+static int __cpuinit cpu_stop_cpu_callback(struct notifier_block *nfb,
+ unsigned long action, void *hcpu)
+{
+ struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 };
+ unsigned int cpu = (unsigned long)hcpu;
+ struct cpu_stopper *stopper = &per_cpu(cpu_stopper, cpu);
+ struct task_struct *p;
+
+ switch (action & ~CPU_TASKS_FROZEN) {
+ case CPU_UP_PREPARE:
+ BUG_ON(stopper->thread || stopper->enabled ||
+ !list_empty(&stopper->works));
+ p = kthread_create(cpu_stopper_thread, stopper, "migration/%d",
+ cpu);
+ if (IS_ERR(p))
+ return NOTIFY_BAD;
+ sched_setscheduler_nocheck(p, SCHED_FIFO, ¶m);
+ get_task_struct(p);
+ stopper->thread = p;
+ break;
+
+ case CPU_ONLINE:
+ kthread_bind(stopper->thread, cpu);
+ /* strictly unnecessary, as first user will wake it */
+ wake_up_process(stopper->thread);
+ /* mark enabled */
+ spin_lock_irq(&stopper->lock);
+ stopper->enabled = true;
+ spin_unlock_irq(&stopper->lock);
+ break;
+
+#ifdef CONFIG_HOTPLUG_CPU
+ case CPU_UP_CANCELED:
+ case CPU_DEAD:
+ {
+ struct cpu_stop_work *work;
+
+ /* kill the stopper */
+ kthread_stop(stopper->thread);
+ /* drain remaining works */
+ spin_lock_irq(&stopper->lock);
+ list_for_each_entry(work, &stopper->works, list)
+ cpu_stop_signal_done(work->done, false);
+ stopper->enabled = false;
+ spin_unlock_irq(&stopper->lock);
+ /* release the stopper */
+ put_task_struct(stopper->thread);
+ stopper->thread = NULL;
+ break;
+ }
+#endif
+ }
+
+ return NOTIFY_OK;
+}
+
+/*
+ * Give it a higher priority so that cpu stopper is available to other
+ * cpu notifiers. It currently shares the same priority as sched
+ * migration_notifier.
+ */
+static struct notifier_block __cpuinitdata cpu_stop_cpu_notifier = {
+ .notifier_call = cpu_stop_cpu_callback,
+ .priority = 10,
+};
+
+static int __init cpu_stop_init(void)
+{
+ void *bcpu = (void *)(long)smp_processor_id();
+ unsigned int cpu;
+ int err;
+
+ for_each_possible_cpu(cpu) {
+ struct cpu_stopper *stopper = &per_cpu(cpu_stopper, cpu);
+
+ spin_lock_init(&stopper->lock);
+ INIT_LIST_HEAD(&stopper->works);
+ }
+
+ /* start one for the boot cpu */
+ err = cpu_stop_cpu_callback(&cpu_stop_cpu_notifier, CPU_UP_PREPARE,
+ bcpu);
+ BUG_ON(err == NOTIFY_BAD);
+ cpu_stop_cpu_callback(&cpu_stop_cpu_notifier, CPU_ONLINE, bcpu);
+ register_cpu_notifier(&cpu_stop_cpu_notifier);
+
+ return 0;
+}
+early_initcall(cpu_stop_init);
+
+#ifdef CONFIG_STOP_MACHINE
/* This controls the threads on each CPU. */
enum stopmachine_state {
@@ -26,174 +393,94 @@
/* Exit */
STOPMACHINE_EXIT,
};
-static enum stopmachine_state state;
struct stop_machine_data {
- int (*fn)(void *);
- void *data;
- int fnret;
+ int (*fn)(void *);
+ void *data;
+ /* Like num_online_cpus(), but hotplug cpu uses us, so we need this. */
+ unsigned int num_threads;
+ const struct cpumask *active_cpus;
+
+ enum stopmachine_state state;
+ atomic_t thread_ack;
};
-/* Like num_online_cpus(), but hotplug cpu uses us, so we need this. */
-static unsigned int num_threads;
-static atomic_t thread_ack;
-static DEFINE_MUTEX(lock);
-/* setup_lock protects refcount, stop_machine_wq and stop_machine_work. */
-static DEFINE_MUTEX(setup_lock);
-/* Users of stop_machine. */
-static int refcount;
-static struct workqueue_struct *stop_machine_wq;
-static struct stop_machine_data active, idle;
-static const struct cpumask *active_cpus;
-static void __percpu *stop_machine_work;
-
-static void set_state(enum stopmachine_state newstate)
+static void set_state(struct stop_machine_data *smdata,
+ enum stopmachine_state newstate)
{
/* Reset ack counter. */
- atomic_set(&thread_ack, num_threads);
+ atomic_set(&smdata->thread_ack, smdata->num_threads);
smp_wmb();
- state = newstate;
+ smdata->state = newstate;
}
/* Last one to ack a state moves to the next state. */
-static void ack_state(void)
+static void ack_state(struct stop_machine_data *smdata)
{
- if (atomic_dec_and_test(&thread_ack))
- set_state(state + 1);
+ if (atomic_dec_and_test(&smdata->thread_ack))
+ set_state(smdata, smdata->state + 1);
}
-/* This is the actual function which stops the CPU. It runs
- * in the context of a dedicated stopmachine workqueue. */
-static void stop_cpu(struct work_struct *unused)
+/* This is the cpu_stop function which stops the CPU. */
+static int stop_machine_cpu_stop(void *data)
{
+ struct stop_machine_data *smdata = data;
enum stopmachine_state curstate = STOPMACHINE_NONE;
- struct stop_machine_data *smdata = &idle;
- int cpu = smp_processor_id();
- int err;
+ int cpu = smp_processor_id(), err = 0;
+ bool is_active;
- if (!active_cpus) {
- if (cpu == cpumask_first(cpu_online_mask))
- smdata = &active;
- } else {
- if (cpumask_test_cpu(cpu, active_cpus))
- smdata = &active;
- }
+ if (!smdata->active_cpus)
+ is_active = cpu == cpumask_first(cpu_online_mask);
+ else
+ is_active = cpumask_test_cpu(cpu, smdata->active_cpus);
+
/* Simple state machine */
do {
/* Chill out and ensure we re-read stopmachine_state. */
cpu_relax();
- if (state != curstate) {
- curstate = state;
+ if (smdata->state != curstate) {
+ curstate = smdata->state;
switch (curstate) {
case STOPMACHINE_DISABLE_IRQ:
local_irq_disable();
hard_irq_disable();
break;
case STOPMACHINE_RUN:
- /* On multiple CPUs only a single error code
- * is needed to tell that something failed. */
- err = smdata->fn(smdata->data);
- if (err)
- smdata->fnret = err;
+ if (is_active)
+ err = smdata->fn(smdata->data);
break;
default:
break;
}
- ack_state();
+ ack_state(smdata);
}
} while (curstate != STOPMACHINE_EXIT);
local_irq_enable();
+ return err;
}
-/* Callback for CPUs which aren't supposed to do anything. */
-static int chill(void *unused)
-{
- return 0;
-}
-
-int stop_machine_create(void)
-{
- mutex_lock(&setup_lock);
- if (refcount)
- goto done;
- stop_machine_wq = create_rt_workqueue("kstop");
- if (!stop_machine_wq)
- goto err_out;
- stop_machine_work = alloc_percpu(struct work_struct);
- if (!stop_machine_work)
- goto err_out;
-done:
- refcount++;
- mutex_unlock(&setup_lock);
- return 0;
-
-err_out:
- if (stop_machine_wq)
- destroy_workqueue(stop_machine_wq);
- mutex_unlock(&setup_lock);
- return -ENOMEM;
-}
-EXPORT_SYMBOL_GPL(stop_machine_create);
-
-void stop_machine_destroy(void)
-{
- mutex_lock(&setup_lock);
- refcount--;
- if (refcount)
- goto done;
- destroy_workqueue(stop_machine_wq);
- free_percpu(stop_machine_work);
-done:
- mutex_unlock(&setup_lock);
-}
-EXPORT_SYMBOL_GPL(stop_machine_destroy);
-
int __stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus)
{
- struct work_struct *sm_work;
- int i, ret;
+ struct stop_machine_data smdata = { .fn = fn, .data = data,
+ .num_threads = num_online_cpus(),
+ .active_cpus = cpus };
- /* Set up initial state. */
- mutex_lock(&lock);
- num_threads = num_online_cpus();
- active_cpus = cpus;
- active.fn = fn;
- active.data = data;
- active.fnret = 0;
- idle.fn = chill;
- idle.data = NULL;
-
- set_state(STOPMACHINE_PREPARE);
-
- /* Schedule the stop_cpu work on all cpus: hold this CPU so one
- * doesn't hit this CPU until we're ready. */
- get_cpu();
- for_each_online_cpu(i) {
- sm_work = per_cpu_ptr(stop_machine_work, i);
- INIT_WORK(sm_work, stop_cpu);
- queue_work_on(i, stop_machine_wq, sm_work);
- }
- /* This will release the thread on our CPU. */
- put_cpu();
- flush_workqueue(stop_machine_wq);
- ret = active.fnret;
- mutex_unlock(&lock);
- return ret;
+ /* Set the initial state and stop all online cpus. */
+ set_state(&smdata, STOPMACHINE_PREPARE);
+ return stop_cpus(cpu_online_mask, stop_machine_cpu_stop, &smdata);
}
int stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus)
{
int ret;
- ret = stop_machine_create();
- if (ret)
- return ret;
/* No CPUs can come up or down during this. */
get_online_cpus();
ret = __stop_machine(fn, data, cpus);
put_online_cpus();
- stop_machine_destroy();
return ret;
}
EXPORT_SYMBOL_GPL(stop_machine);
+
+#endif /* CONFIG_STOP_MACHINE */
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index f992762..1d7b9bc 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -150,14 +150,32 @@
touch_softlockup_watchdog();
}
+/*
+ * Updates the per cpu time idle statistics counters
+ */
+static void
+update_ts_time_stats(struct tick_sched *ts, ktime_t now, u64 *last_update_time)
+{
+ ktime_t delta;
+
+ if (ts->idle_active) {
+ delta = ktime_sub(now, ts->idle_entrytime);
+ ts->idle_sleeptime = ktime_add(ts->idle_sleeptime, delta);
+ if (nr_iowait_cpu() > 0)
+ ts->iowait_sleeptime = ktime_add(ts->iowait_sleeptime, delta);
+ ts->idle_entrytime = now;
+ }
+
+ if (last_update_time)
+ *last_update_time = ktime_to_us(now);
+
+}
+
static void tick_nohz_stop_idle(int cpu, ktime_t now)
{
struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
- ktime_t delta;
- delta = ktime_sub(now, ts->idle_entrytime);
- ts->idle_lastupdate = now;
- ts->idle_sleeptime = ktime_add(ts->idle_sleeptime, delta);
+ update_ts_time_stats(ts, now, NULL);
ts->idle_active = 0;
sched_clock_idle_wakeup_event(0);
@@ -165,20 +183,32 @@
static ktime_t tick_nohz_start_idle(struct tick_sched *ts)
{
- ktime_t now, delta;
+ ktime_t now;
now = ktime_get();
- if (ts->idle_active) {
- delta = ktime_sub(now, ts->idle_entrytime);
- ts->idle_lastupdate = now;
- ts->idle_sleeptime = ktime_add(ts->idle_sleeptime, delta);
- }
+
+ update_ts_time_stats(ts, now, NULL);
+
ts->idle_entrytime = now;
ts->idle_active = 1;
sched_clock_idle_sleep_event();
return now;
}
+/**
+ * get_cpu_idle_time_us - get the total idle time of a cpu
+ * @cpu: CPU number to query
+ * @last_update_time: variable to store update time in
+ *
+ * Return the cummulative idle time (since boot) for a given
+ * CPU, in microseconds. The idle time returned includes
+ * the iowait time (unlike what "top" and co report).
+ *
+ * This time is measured via accounting rather than sampling,
+ * and is as accurate as ktime_get() is.
+ *
+ * This function returns -1 if NOHZ is not enabled.
+ */
u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time)
{
struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
@@ -186,15 +216,38 @@
if (!tick_nohz_enabled)
return -1;
- if (ts->idle_active)
- *last_update_time = ktime_to_us(ts->idle_lastupdate);
- else
- *last_update_time = ktime_to_us(ktime_get());
+ update_ts_time_stats(ts, ktime_get(), last_update_time);
return ktime_to_us(ts->idle_sleeptime);
}
EXPORT_SYMBOL_GPL(get_cpu_idle_time_us);
+/*
+ * get_cpu_iowait_time_us - get the total iowait time of a cpu
+ * @cpu: CPU number to query
+ * @last_update_time: variable to store update time in
+ *
+ * Return the cummulative iowait time (since boot) for a given
+ * CPU, in microseconds.
+ *
+ * This time is measured via accounting rather than sampling,
+ * and is as accurate as ktime_get() is.
+ *
+ * This function returns -1 if NOHZ is not enabled.
+ */
+u64 get_cpu_iowait_time_us(int cpu, u64 *last_update_time)
+{
+ struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
+
+ if (!tick_nohz_enabled)
+ return -1;
+
+ update_ts_time_stats(ts, ktime_get(), last_update_time);
+
+ return ktime_to_us(ts->iowait_sleeptime);
+}
+EXPORT_SYMBOL_GPL(get_cpu_iowait_time_us);
+
/**
* tick_nohz_stop_sched_tick - stop the idle tick from the idle task
*
@@ -262,6 +315,9 @@
goto end;
}
+ if (nohz_ratelimit(cpu))
+ goto end;
+
ts->idle_calls++;
/* Read jiffies and the time when jiffies were updated last */
do {
diff --git a/kernel/time/timer_list.c b/kernel/time/timer_list.c
index 1a4a7dd..ab8f5e3 100644
--- a/kernel/time/timer_list.c
+++ b/kernel/time/timer_list.c
@@ -176,6 +176,7 @@
P_ns(idle_waketime);
P_ns(idle_exittime);
P_ns(idle_sleeptime);
+ P_ns(iowait_sleeptime);
P(last_jiffies);
P(next_jiffies);
P_ns(idle_expires);
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 2404b59..aa3a92b 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -3212,8 +3212,7 @@
}
static void
-ftrace_graph_probe_sched_switch(struct rq *__rq, struct task_struct *prev,
- struct task_struct *next)
+ftrace_graph_probe_sched_switch(struct task_struct *prev, struct task_struct *next)
{
unsigned long long timestamp;
int index;
diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c
index 5fca0f5..a55fccf 100644
--- a/kernel/trace/trace_sched_switch.c
+++ b/kernel/trace/trace_sched_switch.c
@@ -50,8 +50,7 @@
}
static void
-probe_sched_switch(struct rq *__rq, struct task_struct *prev,
- struct task_struct *next)
+probe_sched_switch(struct task_struct *prev, struct task_struct *next)
{
struct trace_array_cpu *data;
unsigned long flags;
@@ -109,7 +108,7 @@
}
static void
-probe_sched_wakeup(struct rq *__rq, struct task_struct *wakee, int success)
+probe_sched_wakeup(struct task_struct *wakee, int success)
{
struct trace_array_cpu *data;
unsigned long flags;
diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c
index 0271742..8052446 100644
--- a/kernel/trace/trace_sched_wakeup.c
+++ b/kernel/trace/trace_sched_wakeup.c
@@ -107,8 +107,7 @@
}
static void notrace
-probe_wakeup_sched_switch(struct rq *rq, struct task_struct *prev,
- struct task_struct *next)
+probe_wakeup_sched_switch(struct task_struct *prev, struct task_struct *next)
{
struct trace_array_cpu *data;
cycle_t T0, T1, delta;
@@ -200,7 +199,7 @@
}
static void
-probe_wakeup(struct rq *rq, struct task_struct *p, int success)
+probe_wakeup(struct task_struct *p, int success)
{
struct trace_array_cpu *data;
int cpu = smp_processor_id();
diff --git a/kernel/user.c b/kernel/user.c
index 766467b..7e72614 100644
--- a/kernel/user.c
+++ b/kernel/user.c
@@ -16,7 +16,6 @@
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/user_namespace.h>
-#include "cred-internals.h"
struct user_namespace init_user_ns = {
.kref = {
@@ -137,9 +136,6 @@
struct hlist_head *hashent = uidhashentry(ns, uid);
struct user_struct *up, *new;
- /* Make uid_hash_find() + uids_user_create() + uid_hash_insert()
- * atomic.
- */
spin_lock_irq(&uidhash_lock);
up = uid_hash_find(uid, hashent);
spin_unlock_irq(&uidhash_lock);
@@ -161,11 +157,6 @@
spin_lock_irq(&uidhash_lock);
up = uid_hash_find(uid, hashent);
if (up) {
- /* This case is not possible when CONFIG_USER_SCHED
- * is defined, since we serialize alloc_uid() using
- * uids_mutex. Hence no need to call
- * sched_destroy_user() or remove_user_sysfs_dir().
- */
key_put(new->uid_keyring);
key_put(new->session_keyring);
kmem_cache_free(uid_cachep, new);
@@ -178,8 +169,6 @@
return up;
- put_user_ns(new->user_ns);
- kmem_cache_free(uid_cachep, new);
out_unlock:
return NULL;
}
