Commit 48e22d56 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

perf_counter: x86: Remove interrupt throttle 



remove the x86 specific interrupt throttle

Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
LKML-Reference: <20090525153931.616671838@chello.nl>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent ff99be57

arch/x86/kernel/apic/apic.c

+0 −2
Original line number Diff line number Diff line
@@ -763,8 +763,6 @@ static void local_apic_timer_interrupt(void) 
	inc_irq_stat(apic_timer_irqs);



	evt->event_handler(evt);



	perf_counter_unthrottle();

}



/*

arch/x86/kernel/cpu/perf_counter.c

+5 −42
Original line number Diff line number Diff line
@@ -718,11 +718,6 @@ static void intel_pmu_save_and_restart(struct perf_counter *counter) 
		intel_pmu_enable_counter(hwc, idx);

}



/*

 * Maximum interrupt frequency of 100KHz per CPU

 */

#define PERFMON_MAX_INTERRUPTS (100000/HZ)



/*

 * This handler is triggered by the local APIC, so the APIC IRQ handling

 * rules apply:
@@ -775,7 +770,6 @@ static int intel_pmu_handle_irq(struct pt_regs *regs, int nmi) 
	if (status)

		goto again;



	if (++cpuc->interrupts != PERFMON_MAX_INTERRUPTS)

	perf_enable();



	return 1;
@@ -783,7 +777,7 @@ static int intel_pmu_handle_irq(struct pt_regs *regs, int nmi) 


static int amd_pmu_handle_irq(struct pt_regs *regs, int nmi)

{

	int cpu, idx, throttle = 0, handled = 0;

	int cpu, idx, handled = 0;

	struct cpu_hw_counters *cpuc;

	struct perf_counter *counter;

	struct hw_perf_counter *hwc;
@@ -792,16 +786,7 @@ static int amd_pmu_handle_irq(struct pt_regs *regs, int nmi) 
	cpu = smp_processor_id();

	cpuc = &per_cpu(cpu_hw_counters, cpu);



	if (++cpuc->interrupts == PERFMON_MAX_INTERRUPTS) {

		throttle = 1;

		__perf_disable();

		cpuc->enabled = 0;

		barrier();

	}



	for (idx = 0; idx < x86_pmu.num_counters; idx++) {

		int disable = 0;



		if (!test_bit(idx, cpuc->active_mask))

			continue;
@@ -809,45 +794,23 @@ static int amd_pmu_handle_irq(struct pt_regs *regs, int nmi) 
		hwc = &counter->hw;



		if (counter->hw_event.nmi != nmi)

			goto next;

			continue;



		val = x86_perf_counter_update(counter, hwc, idx);

		if (val & (1ULL << (x86_pmu.counter_bits - 1)))

			goto next;

			continue;



		/* counter overflow */

		x86_perf_counter_set_period(counter, hwc, idx);

		handled = 1;

		inc_irq_stat(apic_perf_irqs);

		disable = perf_counter_overflow(counter, nmi, regs, 0);



next:

		if (disable || throttle)

		if (perf_counter_overflow(counter, nmi, regs, 0))

			amd_pmu_disable_counter(hwc, idx);

	}



	return handled;

}



void perf_counter_unthrottle(void)

{

	struct cpu_hw_counters *cpuc;



	if (!x86_pmu_initialized())

		return;



	cpuc = &__get_cpu_var(cpu_hw_counters);

	if (cpuc->interrupts >= PERFMON_MAX_INTERRUPTS) {

		/*

		 * Clear them before re-enabling irqs/NMIs again:

		 */

		cpuc->interrupts = 0;

		perf_enable();

	} else {

		cpuc->interrupts = 0;

	}

}



void smp_perf_counter_interrupt(struct pt_regs *regs)

{

	irq_enter();

include/linux/perf_counter.h

+0 −2
Original line number Diff line number Diff line
@@ -570,7 +570,6 @@ extern int perf_counter_init_task(struct task_struct *child); 
extern void perf_counter_exit_task(struct task_struct *child);

extern void perf_counter_do_pending(void);

extern void perf_counter_print_debug(void);

extern void perf_counter_unthrottle(void);

extern void __perf_disable(void);

extern bool __perf_enable(void);

extern void perf_disable(void);
@@ -635,7 +634,6 @@ static inline int perf_counter_init_task(struct task_struct *child) { } 
static inline void perf_counter_exit_task(struct task_struct *child)	{ }

static inline void perf_counter_do_pending(void)			{ }

static inline void perf_counter_print_debug(void)			{ }

static inline void perf_counter_unthrottle(void)			{ }

static inline void perf_disable(void)					{ }

static inline void perf_enable(void)					{ }

static inline int perf_counter_task_disable(void)	{ return -EINVAL; }