From ede1b4290781ae82ccf0f2ecc6dada8d3dd35779 Mon Sep 17 00:00:00 2001 From: Arjan van de Ven Date: Wed, 18 Aug 2010 15:33:13 -0700 Subject: tracing: Fix timer tracing PowerTOP would like to be able to trace timers. Unfortunately, the current timer tracing is not very useful: the actual timer function is not recorded in the trace at the start of timer execution. Although this is recorded for timer "start" time (when it gets armed), this is not useful; most timers get started early, and a tracer like PowerTOP will never see this event, but will only see the actual running of the timer. This patch just adds the function to the timer tracing; I've verified with PowerTOP that now it can get useful information about timers. Signed-off-by: Arjan van de Ven Cc: xiaoguangrong@cn.fujitsu.com Cc: Steven Rostedt Cc: Frederic Weisbecker Cc: Peter Zijlstra Cc: # .35.x, .34.x, .33.x LKML-Reference: <4C6C5FA9.3000405@linux.intel.com> Signed-off-by: Ingo Molnar --- include/trace/events/timer.h | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/include/trace/events/timer.h b/include/trace/events/timer.h index c624126a9c8..425bcfe56c6 100644 --- a/include/trace/events/timer.h +++ b/include/trace/events/timer.h @@ -81,14 +81,16 @@ TRACE_EVENT(timer_expire_entry, TP_STRUCT__entry( __field( void *, timer ) __field( unsigned long, now ) + __field( void *, function) ), TP_fast_assign( __entry->timer = timer; __entry->now = jiffies; + __entry->function = timer->function; ), - TP_printk("timer=%p now=%lu", __entry->timer, __entry->now) + TP_printk("timer=%p function=%pf now=%lu", __entry->timer, __entry->function,__entry->now) ); /** @@ -200,14 +202,16 @@ TRACE_EVENT(hrtimer_expire_entry, TP_STRUCT__entry( __field( void *, hrtimer ) __field( s64, now ) + __field( void *, function) ), TP_fast_assign( __entry->hrtimer = hrtimer; __entry->now = now->tv64; + __entry->function = hrtimer->function; ), - TP_printk("hrtimer=%p now=%llu", __entry->hrtimer, + TP_printk("hrtimer=%p function=%pf now=%llu", __entry->hrtimer, __entry->function, (unsigned long long)ktime_to_ns((ktime_t) { .tv64 = __entry->now })) ); -- cgit v1.2.3-18-g5258 From c6db67cda735d8ace5f19c3831240e1408679790 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Fri, 20 Aug 2010 11:49:15 +0200 Subject: watchdog: Don't throttle the watchdog Stephane reported that when the machine locks up, the regular ticks, which are responsible to resetting the throttle count, stop too. Hence the NMI watchdog can end up being throttled before it reports on the locked up state, and we end up being sad.. Cure this by having the watchdog overflow reset its own throttle count. Reported-by: Stephane Eranian Tested-by: Stephane Eranian Cc: Don Zickus Cc: Frederic Weisbecker Signed-off-by: Peter Zijlstra LKML-Reference: <1282215916.1926.4696.camel@laptop> Signed-off-by: Ingo Molnar --- kernel/watchdog.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/watchdog.c b/kernel/watchdog.c index 613bc1f0461..0d53c8e853b 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -206,6 +206,9 @@ void watchdog_overflow_callback(struct perf_event *event, int nmi, struct perf_sample_data *data, struct pt_regs *regs) { + /* Ensure the watchdog never gets throttled */ + event->hw.interrupts = 0; + if (__get_cpu_var(watchdog_nmi_touch) == true) { __get_cpu_var(watchdog_nmi_touch) = false; return; -- cgit v1.2.3-18-g5258