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| author | Sasha Levin <levinsasha928@gmail.com> | 2012-03-15 17:47:20 -0400 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2012-04-25 12:39:25 +0200 |
| commit | 625056b65ee9a8b4caf42136e0c844c15e6ec54f (patch) | |
| tree | c9470f12694d950bf7e83c3539afa7dea02ba42f /kernel/hung_task.c | |
| parent | af3a3ab2966112c0d0a44df7eeb1e95fe32d4495 (diff) | |
| download | lwn-625056b65ee9a8b4caf42136e0c844c15e6ec54f.tar.gz lwn-625056b65ee9a8b4caf42136e0c844c15e6ec54f.zip | |
hung task debugging: Inject NMI when hung and going to panic
Send an NMI to all CPUs when a hung task is detected and the hung
task code is configured to panic. This gives us a fairly uptodate
snapshot of all CPUs in the system.
This lets us get stack trace of all CPUs which makes life easier
trying to debug a deadlock, and the NMI doesn't change anything
since the next step is a kernel panic.
Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/1331848040-1676-1-git-send-email-levinsasha928@gmail.com
[ extended the changelog a bit ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/hung_task.c')
| -rw-r--r-- | kernel/hung_task.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/kernel/hung_task.c b/kernel/hung_task.c index c21449f85a2a..6df614912b9d 100644 --- a/kernel/hung_task.c +++ b/kernel/hung_task.c @@ -108,8 +108,10 @@ static void check_hung_task(struct task_struct *t, unsigned long timeout) touch_nmi_watchdog(); - if (sysctl_hung_task_panic) + if (sysctl_hung_task_panic) { + trigger_all_cpu_backtrace(); panic("hung_task: blocked tasks"); + } } /* |