| Message ID | 20110706231337.327165192@samba.org (mailing list archive) |
|---|---|
| State | Accepted, archived |
| Commit | 7a0200f66b0b9ad7c4eb8d3f4d3ebdf3c89a55cc |
| Headers | show |
> As a result of changes to Kconfig files, we no longer enable > the lockup and hung task detectors. Both are very light weight > and provide useful information in the event of a hang, so > reenable them. ... > +CONFIG_LOCKUP_DETECTOR=y > +CONFIG_DETECT_HUNG_TASK=y Is one of thise responsible for generating a kernel stack traceback when a process has been sleeping uninterruptably for a 'long' time? We have a kernel subsystem that has several 'worker' threads, these always sleep uninterruptable (they are shut down by explicit request) and, at times, can be idle for long periods. Perhaps it should be possible to disable the check either on a per-process of per sleep basis? David
Hi David, > > As a result of changes to Kconfig files, we no longer enable > > the lockup and hung task detectors. Both are very light weight > > and provide useful information in the event of a hang, so > > reenable them. > ... > > +CONFIG_LOCKUP_DETECTOR=y > > +CONFIG_DETECT_HUNG_TASK=y > > Is one of thise responsible for generating a kernel stack traceback > when a process has been sleeping uninterruptably for a 'long' time? > > We have a kernel subsystem that has several 'worker' threads, > these always sleep uninterruptable (they are shut down by explicit > request) and, at times, can be idle for long periods. > > Perhaps it should be possible to disable the check either on > a per-process of per sleep basis? I don't see any runtime options other than disabling it completely via: /proc/sys/kernel/hung_task_timeout_secs Anton
Index: linux-powerpc/arch/powerpc/configs/ppc64_defconfig =================================================================== --- linux-powerpc.orig/arch/powerpc/configs/ppc64_defconfig 2011-07-07 09:07:31.242982461 +1000 +++ linux-powerpc/arch/powerpc/configs/ppc64_defconfig 2011-07-07 09:07:32.693008109 +1000 @@ -443,6 +443,8 @@ CONFIG_NLS_KOI8_U=m CONFIG_CRC_T10DIF=y CONFIG_MAGIC_SYSRQ=y CONFIG_DEBUG_KERNEL=y +CONFIG_LOCKUP_DETECTOR=y +CONFIG_DETECT_HUNG_TASK=y CONFIG_DEBUG_MUTEXES=y # CONFIG_RCU_CPU_STALL_DETECTOR is not set CONFIG_LATENCYTOP=y Index: linux-powerpc/arch/powerpc/configs/pseries_defconfig =================================================================== --- linux-powerpc.orig/arch/powerpc/configs/pseries_defconfig 2011-07-07 09:07:31.242982461 +1000 +++ linux-powerpc/arch/powerpc/configs/pseries_defconfig 2011-07-07 09:07:32.693008109 +1000 @@ -321,6 +321,8 @@ CONFIG_NLS_ISO8859_1=y CONFIG_CRC_T10DIF=y CONFIG_MAGIC_SYSRQ=y CONFIG_DEBUG_KERNEL=y +CONFIG_LOCKUP_DETECTOR=y +CONFIG_DETECT_HUNG_TASK=y # CONFIG_RCU_CPU_STALL_DETECTOR is not set CONFIG_LATENCYTOP=y CONFIG_SYSCTL_SYSCALL_CHECK=y
As a result of changes to Kconfig files, we no longer enable the lockup and hung task detectors. Both are very light weight and provide useful information in the event of a hang, so reenable them. Signed-off-by: Anton Blanchard <anton@samba.org> ---