From ede1b4290781ae82ccf0f2ecc6dada8d3dd35779 Mon Sep 17 00:00:00 2001
From: Arjan van de Ven <arjan@linux.intel.com>
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 <arjan@linux.intel.com>
Cc: xiaoguangrong@cn.fujitsu.com
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: <stable@kernel.org> # .35.x, .34.x, .33.x
LKML-Reference: <4C6C5FA9.3000405@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/include/trace/events/timer.h b/include/trace/events/timer.h
index c624126..425bcfe 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 v0.10.2


From c6db67cda735d8ace5f19c3831240e1408679790 Mon Sep 17 00:00:00 2001
From: Peter Zijlstra <a.p.zijlstra@chello.nl>
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 <eranian@google.com>
Tested-by: Stephane Eranian <eranian@google.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1282215916.1926.4696.camel@laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 613bc1f..0d53c8e 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 v0.10.2