kernel/rcutree_trace.c - maze/linux - Git at Google

 /*
  * Read-Copy Update tracing for classic implementation
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  *
  * Copyright IBM Corporation, 2008
  *
  * Papers:  http://www.rdrop.com/users/paulmck/RCU
  *
  * For detailed explanation of Read-Copy Update mechanism see -
  *		Documentation/RCU
  *
  */
 #include <linux/types.h>
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/spinlock.h>
 #include <linux/smp.h>
 #include <linux/rcupdate.h>
 #include <linux/interrupt.h>
 #include <linux/sched.h>
 #include <linux/atomic.h>
 #include <linux/bitops.h>
 #include <linux/module.h>
 #include <linux/completion.h>
 #include <linux/moduleparam.h>
 #include <linux/percpu.h>
 #include <linux/notifier.h>
 #include <linux/cpu.h>
 #include <linux/mutex.h>
 #include <linux/debugfs.h>
 #include <linux/seq_file.h>

 #define RCU_TREE_NONCORE
 #include "rcutree.h"

 #ifdef CONFIG_RCU_BOOST

 DECLARE_PER_CPU(unsigned int, rcu_cpu_kthread_status);
 DECLARE_PER_CPU(unsigned int, rcu_cpu_kthread_cpu);
 DECLARE_PER_CPU(unsigned int, rcu_cpu_kthread_loops);
 DECLARE_PER_CPU(char, rcu_cpu_has_work);

 static char convert_kthread_status(unsigned int kthread_status)
 {
 	if (kthread_status > RCU_KTHREAD_MAX)
 		return '?';
 	return "SRWOY"[kthread_status];
 }

 #endif /* #ifdef CONFIG_RCU_BOOST */

 static void print_one_rcu_data(struct seq_file *m, struct rcu_data *rdp)
 {
 	if (!rdp->beenonline)
 		return;
 	seq_printf(m, "%3d%cc=%lu g=%lu pq=%d pqc=%lu qp=%d",
 		   rdp->cpu,
 		   cpu_is_offline(rdp->cpu) ? '!' : ' ',
 		   rdp->completed, rdp->gpnum,
 		   rdp->passed_quiesc, rdp->passed_quiesc_completed,
 		   rdp->qs_pending);
 #ifdef CONFIG_NO_HZ
 	seq_printf(m, " dt=%d/%d/%d df=%lu",
 		   atomic_read(&rdp->dynticks->dynticks),
 		   rdp->dynticks->dynticks_nesting,
 		   rdp->dynticks->dynticks_nmi_nesting,
 		   rdp->dynticks_fqs);
 #endif /* #ifdef CONFIG_NO_HZ */
 	seq_printf(m, " of=%lu ri=%lu", rdp->offline_fqs, rdp->resched_ipi);
 	seq_printf(m, " ql=%ld qs=%c%c%c%c",
 		   rdp->qlen,
 		   ".N"[rdp->nxttail[RCU_NEXT_READY_TAIL] !=
 			rdp->nxttail[RCU_NEXT_TAIL]],
 		   ".R"[rdp->nxttail[RCU_WAIT_TAIL] !=
 			rdp->nxttail[RCU_NEXT_READY_TAIL]],
 		   ".W"[rdp->nxttail[RCU_DONE_TAIL] !=
 			rdp->nxttail[RCU_WAIT_TAIL]],
 		   ".D"[&rdp->nxtlist != rdp->nxttail[RCU_DONE_TAIL]]);
 #ifdef CONFIG_RCU_BOOST
 	seq_printf(m, " kt=%d/%c/%d ktl=%x",
 		   per_cpu(rcu_cpu_has_work, rdp->cpu),
 		   convert_kthread_status(per_cpu(rcu_cpu_kthread_status,
 					  rdp->cpu)),
 		   per_cpu(rcu_cpu_kthread_cpu, rdp->cpu),
 		   per_cpu(rcu_cpu_kthread_loops, rdp->cpu) & 0xffff);
 #endif /* #ifdef CONFIG_RCU_BOOST */
 	seq_printf(m, " b=%ld", rdp->blimit);
 	seq_printf(m, " ci=%lu co=%lu ca=%lu\n",
 		   rdp->n_cbs_invoked, rdp->n_cbs_orphaned, rdp->n_cbs_adopted);
 }

 #define PRINT_RCU_DATA(name, func, m) \
 	do { \
 		int _p_r_d_i; \
 		\
 		for_each_possible_cpu(_p_r_d_i) \
 			func(m, &per_cpu(name, _p_r_d_i)); \
 	} while (0)

 static int show_rcudata(struct seq_file *m, void *unused)
 {
 #ifdef CONFIG_TREE_PREEMPT_RCU
 	seq_puts(m, "rcu_preempt:\n");
 	PRINT_RCU_DATA(rcu_preempt_data, print_one_rcu_data, m);
 #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
 	seq_puts(m, "rcu_sched:\n");
 	PRINT_RCU_DATA(rcu_sched_data, print_one_rcu_data, m);
 	seq_puts(m, "rcu_bh:\n");
 	PRINT_RCU_DATA(rcu_bh_data, print_one_rcu_data, m);
 	return 0;
 }

 static int rcudata_open(struct inode *inode, struct file *file)
 {
 	return single_open(file, show_rcudata, NULL);
 }

 static const struct file_operations rcudata_fops = {
 	.owner = THIS_MODULE,
 	.open = rcudata_open,
 	.read = seq_read,
 	.llseek = seq_lseek,
 	.release = single_release,
 };

 static void print_one_rcu_data_csv(struct seq_file *m, struct rcu_data *rdp)
 {
 	if (!rdp->beenonline)
 		return;
 	seq_printf(m, "%d,%s,%lu,%lu,%d,%lu,%d",
 		   rdp->cpu,
 		   cpu_is_offline(rdp->cpu) ? "\"N\"" : "\"Y\"",
 		   rdp->completed, rdp->gpnum,
 		   rdp->passed_quiesc, rdp->passed_quiesc_completed,
 		   rdp->qs_pending);
 #ifdef CONFIG_NO_HZ
 	seq_printf(m, ",%d,%d,%d,%lu",
 		   atomic_read(&rdp->dynticks->dynticks),
 		   rdp->dynticks->dynticks_nesting,
 		   rdp->dynticks->dynticks_nmi_nesting,
 		   rdp->dynticks_fqs);
 #endif /* #ifdef CONFIG_NO_HZ */
 	seq_printf(m, ",%lu,%lu", rdp->offline_fqs, rdp->resched_ipi);
 	seq_printf(m, ",%ld,\"%c%c%c%c\"", rdp->qlen,
 		   ".N"[rdp->nxttail[RCU_NEXT_READY_TAIL] !=
 			rdp->nxttail[RCU_NEXT_TAIL]],
 		   ".R"[rdp->nxttail[RCU_WAIT_TAIL] !=
 			rdp->nxttail[RCU_NEXT_READY_TAIL]],
 		   ".W"[rdp->nxttail[RCU_DONE_TAIL] !=
 			rdp->nxttail[RCU_WAIT_TAIL]],
 		   ".D"[&rdp->nxtlist != rdp->nxttail[RCU_DONE_TAIL]]);
 #ifdef CONFIG_RCU_BOOST
 	seq_printf(m, ",%d,\"%c\"",
 		   per_cpu(rcu_cpu_has_work, rdp->cpu),
 		   convert_kthread_status(per_cpu(rcu_cpu_kthread_status,
 					  rdp->cpu)));
 #endif /* #ifdef CONFIG_RCU_BOOST */
 	seq_printf(m, ",%ld", rdp->blimit);
 	seq_printf(m, ",%lu,%lu,%lu\n",
 		   rdp->n_cbs_invoked, rdp->n_cbs_orphaned, rdp->n_cbs_adopted);
 }

 static int show_rcudata_csv(struct seq_file *m, void *unused)
 {
 	seq_puts(m, "\"CPU\",\"Online?\",\"c\",\"g\",\"pq\",\"pqc\",\"pq\",");
 #ifdef CONFIG_NO_HZ
 	seq_puts(m, "\"dt\",\"dt nesting\",\"dt NMI nesting\",\"df\",");
 #endif /* #ifdef CONFIG_NO_HZ */
 	seq_puts(m, "\"of\",\"ri\",\"ql\",\"qs\"");
 #ifdef CONFIG_RCU_BOOST
 	seq_puts(m, "\"kt\",\"ktl\"");
 #endif /* #ifdef CONFIG_RCU_BOOST */
 	seq_puts(m, ",\"b\",\"ci\",\"co\",\"ca\"\n");
 #ifdef CONFIG_TREE_PREEMPT_RCU
 	seq_puts(m, "\"rcu_preempt:\"\n");
 	PRINT_RCU_DATA(rcu_preempt_data, print_one_rcu_data_csv, m);
 #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
 	seq_puts(m, "\"rcu_sched:\"\n");
 	PRINT_RCU_DATA(rcu_sched_data, print_one_rcu_data_csv, m);
 	seq_puts(m, "\"rcu_bh:\"\n");
 	PRINT_RCU_DATA(rcu_bh_data, print_one_rcu_data_csv, m);
 	return 0;
 }

 static int rcudata_csv_open(struct inode *inode, struct file *file)
 {
 	return single_open(file, show_rcudata_csv, NULL);
 }

 static const struct file_operations rcudata_csv_fops = {
 	.owner = THIS_MODULE,
 	.open = rcudata_csv_open,
 	.read = seq_read,
 	.llseek = seq_lseek,
 	.release = single_release,
 };

 #ifdef CONFIG_RCU_BOOST

 static void print_one_rcu_node_boost(struct seq_file *m, struct rcu_node *rnp)
 {
 	seq_printf(m,  "%d:%d tasks=%c%c%c%c kt=%c ntb=%lu neb=%lu nnb=%lu "
 		   "j=%04x bt=%04x\n",
 		   rnp->grplo, rnp->grphi,
 		   "T."[list_empty(&rnp->blkd_tasks)],
 		   "N."[!rnp->gp_tasks],
 		   "E."[!rnp->exp_tasks],
 		   "B."[!rnp->boost_tasks],
 		   convert_kthread_status(rnp->boost_kthread_status),
 		   rnp->n_tasks_boosted, rnp->n_exp_boosts,
 		   rnp->n_normal_boosts,
 		   (int)(jiffies & 0xffff),
 		   (int)(rnp->boost_time & 0xffff));
 	seq_printf(m, "%s: nt=%lu egt=%lu bt=%lu nb=%lu ny=%lu nos=%lu\n",
 		   "     balk",
 		   rnp->n_balk_blkd_tasks,
 		   rnp->n_balk_exp_gp_tasks,
 		   rnp->n_balk_boost_tasks,
 		   rnp->n_balk_notblocked,
 		   rnp->n_balk_notyet,
 		   rnp->n_balk_nos);
 }

 static int show_rcu_node_boost(struct seq_file *m, void *unused)
 {
 	struct rcu_node *rnp;

 	rcu_for_each_leaf_node(&rcu_preempt_state, rnp)
 		print_one_rcu_node_boost(m, rnp);
 	return 0;
 }

 static int rcu_node_boost_open(struct inode *inode, struct file *file)
 {
 	return single_open(file, show_rcu_node_boost, NULL);
 }

 static const struct file_operations rcu_node_boost_fops = {
 	.owner = THIS_MODULE,
 	.open = rcu_node_boost_open,
 	.read = seq_read,
 	.llseek = seq_lseek,
 	.release = single_release,
 };

 /*
  * Create the rcuboost debugfs entry.  Standard error return.
  */
 static int rcu_boost_trace_create_file(struct dentry *rcudir)
 {
 	return !debugfs_create_file("rcuboost", 0444, rcudir, NULL,
 				    &rcu_node_boost_fops);
 }

 #else /* #ifdef CONFIG_RCU_BOOST */

 static int rcu_boost_trace_create_file(struct dentry *rcudir)
 {
 	return 0;  /* There cannot be an error if we didn't create it! */
 }

 #endif /* #else #ifdef CONFIG_RCU_BOOST */

 static void print_one_rcu_state(struct seq_file *m, struct rcu_state *rsp)
 {
 	unsigned long gpnum;
 	int level = 0;
 	struct rcu_node *rnp;

 	gpnum = rsp->gpnum;
 	seq_printf(m, "c=%lu g=%lu s=%d jfq=%ld j=%x "
 		      "nfqs=%lu/nfqsng=%lu(%lu) fqlh=%lu\n",
 		   rsp->completed, gpnum, rsp->signaled,
 		   (long)(rsp->jiffies_force_qs - jiffies),
 		   (int)(jiffies & 0xffff),
 		   rsp->n_force_qs, rsp->n_force_qs_ngp,
 		   rsp->n_force_qs - rsp->n_force_qs_ngp,
 		   rsp->n_force_qs_lh);
 	for (rnp = &rsp->node[0]; rnp - &rsp->node[0] < NUM_RCU_NODES; rnp++) {
 		if (rnp->level != level) {
 			seq_puts(m, "\n");
 			level = rnp->level;
 		}
 		seq_printf(m, "%lx/%lx %c%c>%c %d:%d ^%d    ",
 			   rnp->qsmask, rnp->qsmaskinit,
 			   ".G"[rnp->gp_tasks != NULL],
 			   ".E"[rnp->exp_tasks != NULL],
 			   ".T"[!list_empty(&rnp->blkd_tasks)],
 			   rnp->grplo, rnp->grphi, rnp->grpnum);
 	}
 	seq_puts(m, "\n");
 }

 static int show_rcuhier(struct seq_file *m, void *unused)
 {
 #ifdef CONFIG_TREE_PREEMPT_RCU
 	seq_puts(m, "rcu_preempt:\n");
 	print_one_rcu_state(m, &rcu_preempt_state);
 #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
 	seq_puts(m, "rcu_sched:\n");
 	print_one_rcu_state(m, &rcu_sched_state);
 	seq_puts(m, "rcu_bh:\n");
 	print_one_rcu_state(m, &rcu_bh_state);
 	return 0;
 }

 static int rcuhier_open(struct inode *inode, struct file *file)
 {
 	return single_open(file, show_rcuhier, NULL);
 }

 static const struct file_operations rcuhier_fops = {
 	.owner = THIS_MODULE,
 	.open = rcuhier_open,
 	.read = seq_read,
 	.llseek = seq_lseek,
 	.release = single_release,
 };

 static void show_one_rcugp(struct seq_file *m, struct rcu_state *rsp)
 {
 	unsigned long flags;
 	unsigned long completed;
 	unsigned long gpnum;
 	unsigned long gpage;
 	unsigned long gpmax;
 	struct rcu_node *rnp = &rsp->node[0];

 	raw_spin_lock_irqsave(&rnp->lock, flags);
 	completed = rsp->completed;
 	gpnum = rsp->gpnum;
 	if (rsp->completed == rsp->gpnum)
 		gpage = 0;
 	else
 		gpage = jiffies - rsp->gp_start;
 	gpmax = rsp->gp_max;
 	raw_spin_unlock_irqrestore(&rnp->lock, flags);
 	seq_printf(m, "%s: completed=%ld  gpnum=%lu  age=%ld  max=%ld\n",
 		   rsp->name, completed, gpnum, gpage, gpmax);
 }

 static int show_rcugp(struct seq_file *m, void *unused)
 {
 #ifdef CONFIG_TREE_PREEMPT_RCU
 	show_one_rcugp(m, &rcu_preempt_state);
 #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
 	show_one_rcugp(m, &rcu_sched_state);
 	show_one_rcugp(m, &rcu_bh_state);
 	return 0;
 }

 static int rcugp_open(struct inode *inode, struct file *file)
 {
 	return single_open(file, show_rcugp, NULL);
 }

 static const struct file_operations rcugp_fops = {
 	.owner = THIS_MODULE,
 	.open = rcugp_open,
 	.read = seq_read,
 	.llseek = seq_lseek,
 	.release = single_release,
 };

 static void print_one_rcu_pending(struct seq_file *m, struct rcu_data *rdp)
 {
 	seq_printf(m, "%3d%cnp=%ld "
 		   "qsp=%ld rpq=%ld cbr=%ld cng=%ld "
 		   "gpc=%ld gps=%ld nf=%ld nn=%ld\n",
 		   rdp->cpu,
 		   cpu_is_offline(rdp->cpu) ? '!' : ' ',
 		   rdp->n_rcu_pending,
 		   rdp->n_rp_qs_pending,
 		   rdp->n_rp_report_qs,
 		   rdp->n_rp_cb_ready,
 		   rdp->n_rp_cpu_needs_gp,
 		   rdp->n_rp_gp_completed,
 		   rdp->n_rp_gp_started,
 		   rdp->n_rp_need_fqs,
 		   rdp->n_rp_need_nothing);
 }

 static void print_rcu_pendings(struct seq_file *m, struct rcu_state *rsp)
 {
 	int cpu;
 	struct rcu_data *rdp;

 	for_each_possible_cpu(cpu) {
 		rdp = per_cpu_ptr(rsp->rda, cpu);
 		if (rdp->beenonline)
 			print_one_rcu_pending(m, rdp);
 	}
 }

 static int show_rcu_pending(struct seq_file *m, void *unused)
 {
 #ifdef CONFIG_TREE_PREEMPT_RCU
 	seq_puts(m, "rcu_preempt:\n");
 	print_rcu_pendings(m, &rcu_preempt_state);
 #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
 	seq_puts(m, "rcu_sched:\n");
 	print_rcu_pendings(m, &rcu_sched_state);
 	seq_puts(m, "rcu_bh:\n");
 	print_rcu_pendings(m, &rcu_bh_state);
 	return 0;
 }

 static int rcu_pending_open(struct inode *inode, struct file *file)
 {
 	return single_open(file, show_rcu_pending, NULL);
 }

 static const struct file_operations rcu_pending_fops = {
 	.owner = THIS_MODULE,
 	.open = rcu_pending_open,
 	.read = seq_read,
 	.llseek = seq_lseek,
 	.release = single_release,
 };

 static int show_rcutorture(struct seq_file *m, void *unused)
 {
 	seq_printf(m, "rcutorture test sequence: %lu %s\n",
 		   rcutorture_testseq >> 1,
 		   (rcutorture_testseq & 0x1) ? "(test in progress)" : "");
 	seq_printf(m, "rcutorture update version number: %lu\n",
 		   rcutorture_vernum);
 	return 0;
 }

 static int rcutorture_open(struct inode *inode, struct file *file)
 {
 	return single_open(file, show_rcutorture, NULL);
 }

 static const struct file_operations rcutorture_fops = {
 	.owner = THIS_MODULE,
 	.open = rcutorture_open,
 	.read = seq_read,
 	.llseek = seq_lseek,
 	.release = single_release,
 };

 static struct dentry *rcudir;

 static int __init rcutree_trace_init(void)
 {
 	struct dentry *retval;

 	rcudir = debugfs_create_dir("rcu", NULL);
 	if (!rcudir)
 		goto free_out;

 	retval = debugfs_create_file("rcudata", 0444, rcudir,
 						NULL, &rcudata_fops);
 	if (!retval)
 		goto free_out;

 	retval = debugfs_create_file("rcudata.csv", 0444, rcudir,
 						NULL, &rcudata_csv_fops);
 	if (!retval)
 		goto free_out;

 	if (rcu_boost_trace_create_file(rcudir))
 		goto free_out;

 	retval = debugfs_create_file("rcugp", 0444, rcudir, NULL, &rcugp_fops);
 	if (!retval)
 		goto free_out;

 	retval = debugfs_create_file("rcuhier", 0444, rcudir,
 						NULL, &rcuhier_fops);
 	if (!retval)
 		goto free_out;

 	retval = debugfs_create_file("rcu_pending", 0444, rcudir,
 						NULL, &rcu_pending_fops);
 	if (!retval)
 		goto free_out;

 	retval = debugfs_create_file("rcutorture", 0444, rcudir,
 						NULL, &rcutorture_fops);
 	if (!retval)
 		goto free_out;
 	return 0;
 free_out:
 	debugfs_remove_recursive(rcudir);
 	return 1;
 }

 static void __exit rcutree_trace_cleanup(void)
 {
 	debugfs_remove_recursive(rcudir);
 }


 module_init(rcutree_trace_init);
 module_exit(rcutree_trace_cleanup);

 MODULE_AUTHOR("Paul E. McKenney");
 MODULE_DESCRIPTION("Read-Copy Update tracing for hierarchical implementation");
 MODULE_LICENSE("GPL");
	/*
	* Read-Copy Update tracing for classic implementation
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or
	* (at your option) any later version.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
	*
	* Copyright IBM Corporation, 2008
	*
	* Papers: http://www.rdrop.com/users/paulmck/RCU
	*
	* For detailed explanation of Read-Copy Update mechanism see -
	* Documentation/RCU
	*
	*/
	#include <linux/types.h>
	#include <linux/kernel.h>
	#include <linux/init.h>
	#include <linux/spinlock.h>
	#include <linux/smp.h>
	#include <linux/rcupdate.h>
	#include <linux/interrupt.h>
	#include <linux/sched.h>
	#include <linux/atomic.h>
	#include <linux/bitops.h>
	#include <linux/module.h>
	#include <linux/completion.h>
	#include <linux/moduleparam.h>
	#include <linux/percpu.h>
	#include <linux/notifier.h>
	#include <linux/cpu.h>
	#include <linux/mutex.h>
	#include <linux/debugfs.h>
	#include <linux/seq_file.h>

	#define RCU_TREE_NONCORE
	#include "rcutree.h"

	#ifdef CONFIG_RCU_BOOST

	DECLARE_PER_CPU(unsigned int, rcu_cpu_kthread_status);
	DECLARE_PER_CPU(unsigned int, rcu_cpu_kthread_cpu);
	DECLARE_PER_CPU(unsigned int, rcu_cpu_kthread_loops);
	DECLARE_PER_CPU(char, rcu_cpu_has_work);

	static char convert_kthread_status(unsigned int kthread_status)
	{
	if (kthread_status > RCU_KTHREAD_MAX)
	return '?';
	return "SRWOY"[kthread_status];
	}

	#endif /* #ifdef CONFIG_RCU_BOOST */

	static void print_one_rcu_data(struct seq_file m, struct rcu_data rdp)
	{
	if (!rdp->beenonline)
	return;
	seq_printf(m, "%3d%cc=%lu g=%lu pq=%d pqc=%lu qp=%d",
	rdp->cpu,
	cpu_is_offline(rdp->cpu) ? '!' : ' ',
	rdp->completed, rdp->gpnum,
	rdp->passed_quiesc, rdp->passed_quiesc_completed,
	rdp->qs_pending);
	#ifdef CONFIG_NO_HZ
	seq_printf(m, " dt=%d/%d/%d df=%lu",
	atomic_read(&rdp->dynticks->dynticks),
	rdp->dynticks->dynticks_nesting,
	rdp->dynticks->dynticks_nmi_nesting,
	rdp->dynticks_fqs);
	#endif /* #ifdef CONFIG_NO_HZ */
	seq_printf(m, " of=%lu ri=%lu", rdp->offline_fqs, rdp->resched_ipi);
	seq_printf(m, " ql=%ld qs=%c%c%c%c",
	rdp->qlen,
	".N"[rdp->nxttail[RCU_NEXT_READY_TAIL] !=
	rdp->nxttail[RCU_NEXT_TAIL]],
	".R"[rdp->nxttail[RCU_WAIT_TAIL] !=
	rdp->nxttail[RCU_NEXT_READY_TAIL]],
	".W"[rdp->nxttail[RCU_DONE_TAIL] !=
	rdp->nxttail[RCU_WAIT_TAIL]],
	".D"[&rdp->nxtlist != rdp->nxttail[RCU_DONE_TAIL]]);
	#ifdef CONFIG_RCU_BOOST
	seq_printf(m, " kt=%d/%c/%d ktl=%x",
	per_cpu(rcu_cpu_has_work, rdp->cpu),
	convert_kthread_status(per_cpu(rcu_cpu_kthread_status,
	rdp->cpu)),
	per_cpu(rcu_cpu_kthread_cpu, rdp->cpu),
	per_cpu(rcu_cpu_kthread_loops, rdp->cpu) & 0xffff);
	#endif /* #ifdef CONFIG_RCU_BOOST */
	seq_printf(m, " b=%ld", rdp->blimit);
	seq_printf(m, " ci=%lu co=%lu ca=%lu\n",
	rdp->n_cbs_invoked, rdp->n_cbs_orphaned, rdp->n_cbs_adopted);
	}

	#define PRINT_RCU_DATA(name, func, m) \
	do { \
	int _p_r_d_i; \
	\
	for_each_possible_cpu(_p_r_d_i) \
	func(m, &per_cpu(name, _p_r_d_i)); \
	} while (0)

	static int show_rcudata(struct seq_file m, void unused)
	{
	#ifdef CONFIG_TREE_PREEMPT_RCU
	seq_puts(m, "rcu_preempt:\n");
	PRINT_RCU_DATA(rcu_preempt_data, print_one_rcu_data, m);
	#endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
	seq_puts(m, "rcu_sched:\n");
	PRINT_RCU_DATA(rcu_sched_data, print_one_rcu_data, m);
	seq_puts(m, "rcu_bh:\n");
	PRINT_RCU_DATA(rcu_bh_data, print_one_rcu_data, m);
	return 0;
	}

	static int rcudata_open(struct inode inode, struct file file)
	{
	return single_open(file, show_rcudata, NULL);
	}

	static const struct file_operations rcudata_fops = {
	.owner = THIS_MODULE,
	.open = rcudata_open,
	.read = seq_read,
	.llseek = seq_lseek,
	.release = single_release,
	};

	static void print_one_rcu_data_csv(struct seq_file m, struct rcu_data rdp)
	{
	if (!rdp->beenonline)
	return;
	seq_printf(m, "%d,%s,%lu,%lu,%d,%lu,%d",
	rdp->cpu,
	cpu_is_offline(rdp->cpu) ? "\"N\"" : "\"Y\"",
	rdp->completed, rdp->gpnum,
	rdp->passed_quiesc, rdp->passed_quiesc_completed,
	rdp->qs_pending);
	#ifdef CONFIG_NO_HZ
	seq_printf(m, ",%d,%d,%d,%lu",
	atomic_read(&rdp->dynticks->dynticks),
	rdp->dynticks->dynticks_nesting,
	rdp->dynticks->dynticks_nmi_nesting,
	rdp->dynticks_fqs);
	#endif /* #ifdef CONFIG_NO_HZ */
	seq_printf(m, ",%lu,%lu", rdp->offline_fqs, rdp->resched_ipi);
	seq_printf(m, ",%ld,\"%c%c%c%c\"", rdp->qlen,
	".N"[rdp->nxttail[RCU_NEXT_READY_TAIL] !=
	rdp->nxttail[RCU_NEXT_TAIL]],
	".R"[rdp->nxttail[RCU_WAIT_TAIL] !=
	rdp->nxttail[RCU_NEXT_READY_TAIL]],
	".W"[rdp->nxttail[RCU_DONE_TAIL] !=
	rdp->nxttail[RCU_WAIT_TAIL]],
	".D"[&rdp->nxtlist != rdp->nxttail[RCU_DONE_TAIL]]);
	#ifdef CONFIG_RCU_BOOST
	seq_printf(m, ",%d,\"%c\"",
	per_cpu(rcu_cpu_has_work, rdp->cpu),
	convert_kthread_status(per_cpu(rcu_cpu_kthread_status,
	rdp->cpu)));
	#endif /* #ifdef CONFIG_RCU_BOOST */
	seq_printf(m, ",%ld", rdp->blimit);
	seq_printf(m, ",%lu,%lu,%lu\n",
	rdp->n_cbs_invoked, rdp->n_cbs_orphaned, rdp->n_cbs_adopted);
	}

	static int show_rcudata_csv(struct seq_file m, void unused)
	{
	seq_puts(m, "\"CPU\",\"Online?\",\"c\",\"g\",\"pq\",\"pqc\",\"pq\",");
	#ifdef CONFIG_NO_HZ
	seq_puts(m, "\"dt\",\"dt nesting\",\"dt NMI nesting\",\"df\",");
	#endif /* #ifdef CONFIG_NO_HZ */
	seq_puts(m, "\"of\",\"ri\",\"ql\",\"qs\"");
	#ifdef CONFIG_RCU_BOOST
	seq_puts(m, "\"kt\",\"ktl\"");
	#endif /* #ifdef CONFIG_RCU_BOOST */
	seq_puts(m, ",\"b\",\"ci\",\"co\",\"ca\"\n");
	#ifdef CONFIG_TREE_PREEMPT_RCU
	seq_puts(m, "\"rcu_preempt:\"\n");
	PRINT_RCU_DATA(rcu_preempt_data, print_one_rcu_data_csv, m);
	#endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
	seq_puts(m, "\"rcu_sched:\"\n");
	PRINT_RCU_DATA(rcu_sched_data, print_one_rcu_data_csv, m);
	seq_puts(m, "\"rcu_bh:\"\n");
	PRINT_RCU_DATA(rcu_bh_data, print_one_rcu_data_csv, m);
	return 0;
	}

	static int rcudata_csv_open(struct inode inode, struct file file)
	{
	return single_open(file, show_rcudata_csv, NULL);
	}

	static const struct file_operations rcudata_csv_fops = {
	.owner = THIS_MODULE,
	.open = rcudata_csv_open,
	.read = seq_read,
	.llseek = seq_lseek,
	.release = single_release,
	};

	#ifdef CONFIG_RCU_BOOST

	static void print_one_rcu_node_boost(struct seq_file m, struct rcu_node rnp)
	{
	seq_printf(m, "%d:%d tasks=%c%c%c%c kt=%c ntb=%lu neb=%lu nnb=%lu "
	"j=%04x bt=%04x\n",
	rnp->grplo, rnp->grphi,
	"T."[list_empty(&rnp->blkd_tasks)],
	"N."[!rnp->gp_tasks],
	"E."[!rnp->exp_tasks],
	"B."[!rnp->boost_tasks],
	convert_kthread_status(rnp->boost_kthread_status),
	rnp->n_tasks_boosted, rnp->n_exp_boosts,
	rnp->n_normal_boosts,
	(int)(jiffies & 0xffff),
	(int)(rnp->boost_time & 0xffff));
	seq_printf(m, "%s: nt=%lu egt=%lu bt=%lu nb=%lu ny=%lu nos=%lu\n",
	" balk",
	rnp->n_balk_blkd_tasks,
	rnp->n_balk_exp_gp_tasks,
	rnp->n_balk_boost_tasks,
	rnp->n_balk_notblocked,
	rnp->n_balk_notyet,
	rnp->n_balk_nos);
	}

	static int show_rcu_node_boost(struct seq_file m, void unused)
	{
	struct rcu_node *rnp;

	rcu_for_each_leaf_node(&rcu_preempt_state, rnp)
	print_one_rcu_node_boost(m, rnp);
	return 0;
	}

	static int rcu_node_boost_open(struct inode inode, struct file file)
	{
	return single_open(file, show_rcu_node_boost, NULL);
	}

	static const struct file_operations rcu_node_boost_fops = {
	.owner = THIS_MODULE,
	.open = rcu_node_boost_open,
	.read = seq_read,
	.llseek = seq_lseek,
	.release = single_release,
	};

	/*
	* Create the rcuboost debugfs entry. Standard error return.
	*/
	static int rcu_boost_trace_create_file(struct dentry *rcudir)
	{
	return !debugfs_create_file("rcuboost", 0444, rcudir, NULL,
	&rcu_node_boost_fops);
	}

	#else /* #ifdef CONFIG_RCU_BOOST */

	static int rcu_boost_trace_create_file(struct dentry *rcudir)
	{
	return 0; /* There cannot be an error if we didn't create it! */
	}

	#endif /* #else #ifdef CONFIG_RCU_BOOST */

	static void print_one_rcu_state(struct seq_file m, struct rcu_state rsp)
	{
	unsigned long gpnum;
	int level = 0;
	struct rcu_node *rnp;

	gpnum = rsp->gpnum;
	seq_printf(m, "c=%lu g=%lu s=%d jfq=%ld j=%x "
	"nfqs=%lu/nfqsng=%lu(%lu) fqlh=%lu\n",
	rsp->completed, gpnum, rsp->signaled,
	(long)(rsp->jiffies_force_qs - jiffies),
	(int)(jiffies & 0xffff),
	rsp->n_force_qs, rsp->n_force_qs_ngp,
	rsp->n_force_qs - rsp->n_force_qs_ngp,
	rsp->n_force_qs_lh);
	for (rnp = &rsp->node[0]; rnp - &rsp->node[0] < NUM_RCU_NODES; rnp++) {
	if (rnp->level != level) {
	seq_puts(m, "\n");
	level = rnp->level;
	}
	seq_printf(m, "%lx/%lx %c%c>%c %d:%d ^%d ",
	rnp->qsmask, rnp->qsmaskinit,
	".G"[rnp->gp_tasks != NULL],
	".E"[rnp->exp_tasks != NULL],
	".T"[!list_empty(&rnp->blkd_tasks)],
	rnp->grplo, rnp->grphi, rnp->grpnum);
	}
	seq_puts(m, "\n");
	}

	static int show_rcuhier(struct seq_file m, void unused)
	{
	#ifdef CONFIG_TREE_PREEMPT_RCU
	seq_puts(m, "rcu_preempt:\n");
	print_one_rcu_state(m, &rcu_preempt_state);
	#endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
	seq_puts(m, "rcu_sched:\n");
	print_one_rcu_state(m, &rcu_sched_state);
	seq_puts(m, "rcu_bh:\n");
	print_one_rcu_state(m, &rcu_bh_state);
	return 0;
	}

	static int rcuhier_open(struct inode inode, struct file file)
	{
	return single_open(file, show_rcuhier, NULL);
	}

	static const struct file_operations rcuhier_fops = {
	.owner = THIS_MODULE,
	.open = rcuhier_open,
	.read = seq_read,
	.llseek = seq_lseek,
	.release = single_release,
	};

	static void show_one_rcugp(struct seq_file m, struct rcu_state rsp)
	{
	unsigned long flags;
	unsigned long completed;
	unsigned long gpnum;
	unsigned long gpage;
	unsigned long gpmax;
	struct rcu_node *rnp = &rsp->node[0];

	raw_spin_lock_irqsave(&rnp->lock, flags);
	completed = rsp->completed;
	gpnum = rsp->gpnum;
	if (rsp->completed == rsp->gpnum)
	gpage = 0;
	else
	gpage = jiffies - rsp->gp_start;
	gpmax = rsp->gp_max;
	raw_spin_unlock_irqrestore(&rnp->lock, flags);
	seq_printf(m, "%s: completed=%ld gpnum=%lu age=%ld max=%ld\n",
	rsp->name, completed, gpnum, gpage, gpmax);
	}

	static int show_rcugp(struct seq_file m, void unused)
	{
	#ifdef CONFIG_TREE_PREEMPT_RCU
	show_one_rcugp(m, &rcu_preempt_state);
	#endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
	show_one_rcugp(m, &rcu_sched_state);
	show_one_rcugp(m, &rcu_bh_state);
	return 0;
	}

	static int rcugp_open(struct inode inode, struct file file)
	{
	return single_open(file, show_rcugp, NULL);
	}

	static const struct file_operations rcugp_fops = {
	.owner = THIS_MODULE,
	.open = rcugp_open,
	.read = seq_read,
	.llseek = seq_lseek,
	.release = single_release,
	};

	static void print_one_rcu_pending(struct seq_file m, struct rcu_data rdp)
	{
	seq_printf(m, "%3d%cnp=%ld "
	"qsp=%ld rpq=%ld cbr=%ld cng=%ld "
	"gpc=%ld gps=%ld nf=%ld nn=%ld\n",
	rdp->cpu,
	cpu_is_offline(rdp->cpu) ? '!' : ' ',
	rdp->n_rcu_pending,
	rdp->n_rp_qs_pending,
	rdp->n_rp_report_qs,
	rdp->n_rp_cb_ready,
	rdp->n_rp_cpu_needs_gp,
	rdp->n_rp_gp_completed,
	rdp->n_rp_gp_started,
	rdp->n_rp_need_fqs,
	rdp->n_rp_need_nothing);
	}

	static void print_rcu_pendings(struct seq_file m, struct rcu_state rsp)
	{
	int cpu;
	struct rcu_data *rdp;

	for_each_possible_cpu(cpu) {
	rdp = per_cpu_ptr(rsp->rda, cpu);
	if (rdp->beenonline)
	print_one_rcu_pending(m, rdp);
	}
	}

	static int show_rcu_pending(struct seq_file m, void unused)
	{
	#ifdef CONFIG_TREE_PREEMPT_RCU
	seq_puts(m, "rcu_preempt:\n");
	print_rcu_pendings(m, &rcu_preempt_state);
	#endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
	seq_puts(m, "rcu_sched:\n");
	print_rcu_pendings(m, &rcu_sched_state);
	seq_puts(m, "rcu_bh:\n");
	print_rcu_pendings(m, &rcu_bh_state);
	return 0;
	}

	static int rcu_pending_open(struct inode inode, struct file file)
	{
	return single_open(file, show_rcu_pending, NULL);
	}

	static const struct file_operations rcu_pending_fops = {
	.owner = THIS_MODULE,
	.open = rcu_pending_open,
	.read = seq_read,
	.llseek = seq_lseek,
	.release = single_release,
	};

	static int show_rcutorture(struct seq_file m, void unused)
	{
	seq_printf(m, "rcutorture test sequence: %lu %s\n",
	rcutorture_testseq >> 1,
	(rcutorture_testseq & 0x1) ? "(test in progress)" : "");
	seq_printf(m, "rcutorture update version number: %lu\n",
	rcutorture_vernum);
	return 0;
	}

	static int rcutorture_open(struct inode inode, struct file file)
	{
	return single_open(file, show_rcutorture, NULL);
	}

	static const struct file_operations rcutorture_fops = {
	.owner = THIS_MODULE,
	.open = rcutorture_open,
	.read = seq_read,
	.llseek = seq_lseek,
	.release = single_release,
	};

	static struct dentry *rcudir;

	static int __init rcutree_trace_init(void)
	{
	struct dentry *retval;

	rcudir = debugfs_create_dir("rcu", NULL);
	if (!rcudir)
	goto free_out;

	retval = debugfs_create_file("rcudata", 0444, rcudir,
	NULL, &rcudata_fops);
	if (!retval)
	goto free_out;

	retval = debugfs_create_file("rcudata.csv", 0444, rcudir,
	NULL, &rcudata_csv_fops);
	if (!retval)
	goto free_out;

	if (rcu_boost_trace_create_file(rcudir))
	goto free_out;

	retval = debugfs_create_file("rcugp", 0444, rcudir, NULL, &rcugp_fops);
	if (!retval)
	goto free_out;

	retval = debugfs_create_file("rcuhier", 0444, rcudir,
	NULL, &rcuhier_fops);
	if (!retval)
	goto free_out;

	retval = debugfs_create_file("rcu_pending", 0444, rcudir,
	NULL, &rcu_pending_fops);
	if (!retval)
	goto free_out;

	retval = debugfs_create_file("rcutorture", 0444, rcudir,
	NULL, &rcutorture_fops);
	if (!retval)
	goto free_out;
	return 0;
	free_out:
	debugfs_remove_recursive(rcudir);
	return 1;
	}

	static void __exit rcutree_trace_cleanup(void)
	{
	debugfs_remove_recursive(rcudir);
	}


	module_init(rcutree_trace_init);
	module_exit(rcutree_trace_cleanup);

	MODULE_AUTHOR("Paul E. McKenney");
	MODULE_DESCRIPTION("Read-Copy Update tracing for hierarchical implementation");
	MODULE_LICENSE("GPL");