Ingo Molnar 126e01bf92 softlockup: fix NOHZ wakeup ... David Miller reported: |---------------> the following commit: | commit 27ec440779 | Author: Ingo Molnar <mingo@elte.hu> | Date: Thu Feb 28 21:00:21 2008 +0100 | | sched: make cpu_clock() globally synchronous | | Alexey Zaytsev reported (and bisected) that the introduction of | cpu_clock() in printk made the timestamps jump back and forth. | | Make cpu_clock() more reliable while still keeping it fast when it's | called frequently. | | Signed-off-by: Ingo Molnar <mingo@elte.hu> causes watchdog triggers when a cpu exits NOHZ state when it has been there for >= the soft lockup threshold, for example here are some messages from a 128 cpu Niagara2 box: [ 168.106406] BUG: soft lockup - CPU#11 stuck for 128s! [dd:3239] [ 168.989592] BUG: soft lockup - CPU#21 stuck for 86s! [swapper:0] [ 168.999587] BUG: soft lockup - CPU#29 stuck for 91s! [make:4511] [ 168.999615] BUG: soft lockup - CPU#2 stuck for 85s! [swapper:0] [ 169.020514] BUG: soft lockup - CPU#37 stuck for 91s! [swapper:0] [ 169.020514] BUG: soft lockup - CPU#45 stuck for 91s! [sh:4515] [ 169.020515] BUG: soft lockup - CPU#69 stuck for 92s! [swapper:0] [ 169.020515] BUG: soft lockup - CPU#77 stuck for 92s! [swapper:0] [ 169.020515] BUG: soft lockup - CPU#61 stuck for 92s! [swapper:0] [ 169.112554] BUG: soft lockup - CPU#85 stuck for 92s! [swapper:0] [ 169.112554] BUG: soft lockup - CPU#101 stuck for 92s! [swapper:0] [ 169.112554] BUG: soft lockup - CPU#109 stuck for 92s! [swapper:0] [ 169.112554] BUG: soft lockup - CPU#117 stuck for 92s! [swapper:0] [ 169.171483] BUG: soft lockup - CPU#40 stuck for 80s! [dd:3239] [ 169.331483] BUG: soft lockup - CPU#13 stuck for 86s! [swapper:0] [ 169.351500] BUG: soft lockup - CPU#43 stuck for 101s! [dd:3239] [ 169.531482] BUG: soft lockup - CPU#9 stuck for 129s! [mkdir:4565] [ 169.595754] BUG: soft lockup - CPU#20 stuck for 93s! [swapper:0] [ 169.626787] BUG: soft lockup - CPU#52 stuck for 93s! [swapper:0] [ 169.626787] BUG: soft lockup - CPU#84 stuck for 92s! [swapper:0] [ 169.636812] BUG: soft lockup - CPU#116 stuck for 94s! [swapper:0] It's simple enough to trigger this by doing a 10 minute sleep after a fresh bootup then starting a parallel kernel build. I suspect this might be reintroducing a problem we've had and fixed before, see the thread: http://marc.info/?l=linux-kernel&m=119546414004065&w=2 <---------------| touch the softlockup watchdog when exiting NOHZ state - we are obviously not locked up. Signed-off-by: Ingo Molnar <mingo@elte.hu>		2008-04-25 00:25:08 +02:00
..
clockevents.c
clocksource.c	Merge git://git.kernel.org/pub/scm/linux/kernel/git/tglx/linux-2.6-hrt	2008-04-18 08:37:41 -07:00
jiffies.c
Kconfig
Makefile
ntp.c	time: remove obsolete CLOCK_TICK_ADJUST	2008-03-09 08:42:57 +01:00
tick-broadcast.c	clockevents: fix typo in tick-broadcast.c	2008-04-21 07:59:51 +02:00
tick-common.c	[S390] genirq/clockevents: move irq affinity prototypes/inlines to interrupt.h	2008-04-17 07:47:05 +02:00
tick-internal.h
tick-oneshot.c	[S390] genirq/clockevents: move irq affinity prototypes/inlines to interrupt.h	2008-04-17 07:47:05 +02:00
tick-sched.c	softlockup: fix NOHZ wakeup	2008-04-25 00:25:08 +02:00
timekeeping.c	x86: tsc prevent time going backwards	2008-04-19 19:19:55 +02:00
timer_list.c
timer_stats.c