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Commit ee883477 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'perf-fixes-for-linus' of... 

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
parents 609b06f3 4fe757dd

arch/x86/include/asm/perf_event_p4.h

+1 −0
Original line number Diff line number Diff line
@@ -22,6 +22,7 @@ 


#define ARCH_P4_CNTRVAL_BITS	(40)

#define ARCH_P4_CNTRVAL_MASK	((1ULL << ARCH_P4_CNTRVAL_BITS) - 1)

#define ARCH_P4_UNFLAGGED_BIT	((1ULL) << (ARCH_P4_CNTRVAL_BITS - 1))



#define P4_ESCR_EVENT_MASK	0x7e000000U

#define P4_ESCR_EVENT_SHIFT	25

arch/x86/kernel/cpu/perf_event_p4.c

+8 −3
Original line number Diff line number Diff line
@@ -770,9 +770,14 @@ static inline int p4_pmu_clear_cccr_ovf(struct hw_perf_event *hwc) 
		return 1;

	}



	/* it might be unflagged overflow */

	rdmsrl(hwc->event_base + hwc->idx, v);

	if (!(v & ARCH_P4_CNTRVAL_MASK))

	/*

	 * In some circumstances the overflow might issue an NMI but did

	 * not set P4_CCCR_OVF bit. Because a counter holds a negative value

	 * we simply check for high bit being set, if it's cleared it means

	 * the counter has reached zero value and continued counting before

	 * real NMI signal was received:

	 */

	if (!(v & ARCH_P4_UNFLAGGED_BIT))

		return 1;



	return 0;

kernel/perf_event.c

+15 −4
Original line number Diff line number Diff line
@@ -782,6 +782,10 @@ void perf_event_disable(struct perf_event *event) 
	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;