tracing/function-graph-tracer: more output tweaks
Impact: prettify the output some more
Before:
0) | sys_read() {
0) 0.796 us | fget_light();
0) | vfs_read() {
0) | rw_verify_area() {
0) | security_file_permission() {
------------8<---------- thread sshd-1755 ------------8<----------
After:
0) | sys_read() {
0) 0.796 us | fget_light();
0) | vfs_read() {
0) | rw_verify_area() {
0) | security_file_permission() {
------------------------------------------
| 1) migration/0--1 => sshd-1755
------------------------------------------
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index 596a3ee..894b50b 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -79,6 +79,19 @@
int log10_all = log10_cpu(cpus_weight_nr(cpu_online_map));
+ /*
+ * Start with a space character - to make it stand out
+ * to the right a bit when trace output is pasted into
+ * email:
+ */
+ ret = trace_seq_printf(s, " ");
+
+ /*
+ * Tricky - we space the CPU field according to the max
+ * number of online CPUs. On a 2-cpu system it would take
+ * a maximum of 1 digit - on a 128 cpu system it would
+ * take up to 3 digits:
+ */
for (i = 0; i < log10_all - log10_this; i++) {
ret = trace_seq_printf(s, " ");
if (!ret)
@@ -86,7 +99,8 @@
}
ret = trace_seq_printf(s, "%d) ", cpu);
if (!ret)
- return TRACE_TYPE_PARTIAL_LINE;
+ return TRACE_TYPE_PARTIAL_LINE;
+
return TRACE_TYPE_HANDLED;
}
@@ -94,17 +108,34 @@
/* If the pid changed since the last trace, output this event */
static int verif_pid(struct trace_seq *s, pid_t pid, int cpu)
{
- char *comm;
+ char *comm, *prev_comm;
+ pid_t prev_pid;
+ int ret;
if (last_pid[cpu] != -1 && last_pid[cpu] == pid)
return 1;
+ prev_pid = last_pid[cpu];
last_pid[cpu] = pid;
- comm = trace_find_cmdline(pid);
- return trace_seq_printf(s, "\n------------8<---------- thread %s-%d"
- " ------------8<----------\n\n",
- cpu, comm, pid);
+ comm = trace_find_cmdline(pid);
+ prev_comm = trace_find_cmdline(prev_pid);
+
+/*
+ * Context-switch trace line:
+
+ ------------------------------------------
+ | 1) migration/0--1 => sshd-1755
+ ------------------------------------------
+
+ */
+ ret = trace_seq_printf(s,
+ " ------------------------------------------\n");
+ ret += trace_seq_printf(s, " | %d) %s-%d => %s-%d\n",
+ cpu, prev_comm, prev_pid, comm, pid);
+ ret += trace_seq_printf(s,
+ " ------------------------------------------\n\n");
+ return ret;
}
static bool
@@ -142,7 +173,7 @@
print_graph_duration(unsigned long long duration, struct trace_seq *s)
{
unsigned long nsecs_rem = do_div(duration, 1000);
- return trace_seq_printf(s, "%4llu.%3lu us | ", duration, nsecs_rem);
+ return trace_seq_printf(s, "%4llu.%3lu us | ", duration, nsecs_rem);
}
/* Signal a overhead of time execution to the output */
@@ -229,7 +260,7 @@
}
/* No time */
- ret = trace_seq_printf(s, " | ");
+ ret = trace_seq_printf(s, " | ");
/* Function */
for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
