Messages in this thread Patch in this message | | | Date | Wed, 25 Apr 2012 06:53:19 -0700 | From | tip-bot for Sasha Levin <> | Subject | [tip:core/locking] hung task debugging: Inject NMI when hung and going to panic |
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Commit-ID: 625056b65ee9a8b4caf42136e0c844c15e6ec54f Gitweb: http://git.kernel.org/tip/625056b65ee9a8b4caf42136e0c844c15e6ec54f Author: Sasha Levin <levinsasha928@gmail.com> AuthorDate: Thu, 15 Mar 2012 17:47:20 -0400 Committer: Ingo Molnar <mingo@kernel.org> CommitDate: Wed, 25 Apr 2012 12:39:25 +0200
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> --- 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 c21449f..6df6149 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"); + } } /* -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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