diff options
author | Oleg Nesterov <oleg@redhat.com> | 2013-10-19 12:18:28 -0400 |
---|---|---|
committer | Ingo Molnar <mingo@kernel.org> | 2013-10-31 06:16:18 -0400 |
commit | 6a716c90a51338009c3bc1f460829afaed8f922d (patch) | |
tree | 85e821a30e0f9350a2b67ff94d758632eec92689 | |
parent | 4c4e4f61368164f326fe59e2156c70d7faa72c17 (diff) |
hung_task debugging: Add tracepoint to report the hang
Currently check_hung_task() prints a warning if it detects the
problem, but it is not convenient to watch the system logs if
user-space wants to be notified about the hang.
Add the new trace_sched_process_hang() into check_hung_task(),
this way a user-space monitor can easily wait for the hang and
potentially resolve a problem.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Dave Sullivan <dsulliva@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20131019161828.GA7439@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
-rw-r--r-- | include/trace/events/sched.h | 19 | ||||
-rw-r--r-- | kernel/hung_task.c | 4 |
2 files changed, 23 insertions, 0 deletions
diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h index 2e7d9947a10d..2a652d124fbb 100644 --- a/include/trace/events/sched.h +++ b/include/trace/events/sched.h | |||
@@ -424,6 +424,25 @@ TRACE_EVENT(sched_pi_setprio, | |||
424 | __entry->oldprio, __entry->newprio) | 424 | __entry->oldprio, __entry->newprio) |
425 | ); | 425 | ); |
426 | 426 | ||
427 | #ifdef CONFIG_DETECT_HUNG_TASK | ||
428 | TRACE_EVENT(sched_process_hang, | ||
429 | TP_PROTO(struct task_struct *tsk), | ||
430 | TP_ARGS(tsk), | ||
431 | |||
432 | TP_STRUCT__entry( | ||
433 | __array( char, comm, TASK_COMM_LEN ) | ||
434 | __field( pid_t, pid ) | ||
435 | ), | ||
436 | |||
437 | TP_fast_assign( | ||
438 | memcpy(__entry->comm, tsk->comm, TASK_COMM_LEN); | ||
439 | __entry->pid = tsk->pid; | ||
440 | ), | ||
441 | |||
442 | TP_printk("comm=%s pid=%d", __entry->comm, __entry->pid) | ||
443 | ); | ||
444 | #endif /* CONFIG_DETECT_HUNG_TASK */ | ||
445 | |||
427 | #endif /* _TRACE_SCHED_H */ | 446 | #endif /* _TRACE_SCHED_H */ |
428 | 447 | ||
429 | /* This part must be outside protection */ | 448 | /* This part must be outside protection */ |
diff --git a/kernel/hung_task.c b/kernel/hung_task.c index 042252383fd2..8807061ca004 100644 --- a/kernel/hung_task.c +++ b/kernel/hung_task.c | |||
@@ -16,6 +16,7 @@ | |||
16 | #include <linux/export.h> | 16 | #include <linux/export.h> |
17 | #include <linux/sysctl.h> | 17 | #include <linux/sysctl.h> |
18 | #include <linux/utsname.h> | 18 | #include <linux/utsname.h> |
19 | #include <trace/events/sched.h> | ||
19 | 20 | ||
20 | /* | 21 | /* |
21 | * The number of tasks checked: | 22 | * The number of tasks checked: |
@@ -92,6 +93,9 @@ static void check_hung_task(struct task_struct *t, unsigned long timeout) | |||
92 | t->last_switch_count = switch_count; | 93 | t->last_switch_count = switch_count; |
93 | return; | 94 | return; |
94 | } | 95 | } |
96 | |||
97 | trace_sched_process_hang(t); | ||
98 | |||
95 | if (!sysctl_hung_task_warnings) | 99 | if (!sysctl_hung_task_warnings) |
96 | return; | 100 | return; |
97 | sysctl_hung_task_warnings--; | 101 | sysctl_hung_task_warnings--; |