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| author | Ingo Molnar <mingo@elte.hu> | 2005-09-07 00:16:27 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-09-08 01:57:17 +0200 |
| commit | 8446f1d391f3d27e6bf9c43d4cbcdac0ca720417 (patch) | |
| tree | 738853af877c9a391b4f2db467e7f90c6e2e38ed /lib | |
| parent | [PATCH] FUTEX_WAKE_OP: pthread_cond_signal() speedup (diff) | |
| download | linux-8446f1d391f3d27e6bf9c43d4cbcdac0ca720417.tar.xz linux-8446f1d391f3d27e6bf9c43d4cbcdac0ca720417.zip | |
[PATCH] detect soft lockups
This patch adds a new kernel debug feature: CONFIG_DETECT_SOFTLOCKUP.
When enabled then per-CPU watchdog threads are started, which try to run
once per second. If they get delayed for more than 10 seconds then a
callback from the timer interrupt detects this condition and prints out a
warning message and a stack dump (once per lockup incident). The feature
is otherwise non-intrusive, it doesnt try to unlock the box in any way, it
only gets the debug info out, automatically, and on all CPUs affected by
the lockup.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-Off-By: Matthias Urlichs <smurf@smurf.noris.de>
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Kconfig.debug | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 299f7f3b5b08..3754c9a8f5c8 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -46,6 +46,25 @@ config LOG_BUF_SHIFT 13 => 8 KB 12 => 4 KB +config DETECT_SOFTLOCKUP + bool "Detect Soft Lockups" + depends on DEBUG_KERNEL + default y + help + Say Y here to enable the kernel to detect "soft lockups", + which are bugs that cause the kernel to loop in kernel + mode for more than 10 seconds, without giving other tasks a + chance to run. + + When a soft-lockup is detected, the kernel will print the + current stack trace (which you should report), but the + system will stay locked up. This feature has negligible + overhead. + + (Note that "hard lockups" are separate type of bugs that + can be detected via the NMI-watchdog, on platforms that + support it.) + config SCHEDSTATS bool "Collect scheduler statistics" depends on DEBUG_KERNEL && PROC_FS |