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authorLinus Torvalds <torvalds@linux-foundation.org>2011-02-22 09:25:55 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2011-02-22 09:25:55 -0800
commitee88347755460e8ceb37e8453adcf5fd7ca5ff00 (patch)
tree6a604503807d1a342b4e58ffabe11bd2a26661ff /kernel
parent609b06f33506d92693cb89c303026f830f769c0d (diff)
parent4fe757dd48a9e95e1a071291f15dda5421dacb66 (diff)
downloadlinux-linaro-stable-ee88347755460e8ceb37e8453adcf5fd7ca5ff00.tar.gz
Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: perf: Fix throttle logic perf, x86: P4 PMU: Fix spurious NMI messages
Diffstat (limited to 'kernel')
-rw-r--r--kernel/perf_event.c19
1 files changed, 15 insertions, 4 deletions
diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index 999835b6112b..656222fcf767 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -782,6 +782,10 @@ retry:
raw_spin_unlock_irq(&ctx->lock);
}
+#define MAX_INTERRUPTS (~0ULL)
+
+static void perf_log_throttle(struct perf_event *event, int enable);
+
static int
event_sched_in(struct perf_event *event,
struct perf_cpu_context *cpuctx,
@@ -794,6 +798,17 @@ event_sched_in(struct perf_event *event,
event->state = PERF_EVENT_STATE_ACTIVE;
event->oncpu = smp_processor_id();
+
+ /*
+ * Unthrottle events, since we scheduled we might have missed several
+ * ticks already, also for a heavily scheduling task there is little
+ * guarantee it'll get a tick in a timely manner.
+ */
+ if (unlikely(event->hw.interrupts == MAX_INTERRUPTS)) {
+ perf_log_throttle(event, 1);
+ event->hw.interrupts = 0;
+ }
+
/*
* The new state must be visible before we turn it on in the hardware:
*/
@@ -1596,10 +1611,6 @@ void __perf_event_task_sched_in(struct task_struct *task)
}
}
-#define MAX_INTERRUPTS (~0ULL)
-
-static void perf_log_throttle(struct perf_event *event, int enable);
-
static u64 perf_calculate_period(struct perf_event *event, u64 nsec, u64 count)
{
u64 frequency = event->attr.sample_freq;