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Commit 09534238 authored by Robert Richter's avatar Robert Richter Committed by Ingo Molnar
Browse files

perf_counter, x86: generic use of cpuc->active 



cpuc->active will now be used to indicate an enabled counter which
implies also valid pointers of cpuc->counters[]. In contrast,
cpuc->used only locks the counter, but it can be still uninitialized.

[ Impact: refactor and generalize code ]

Signed-off-by: default avatarRobert Richter <robert.richter@amd.com>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1241002046-8832-20-git-send-email-robert.richter@amd.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 93904966

arch/x86/kernel/cpu/perf_counter.c

+9 −11
Original line number Diff line number Diff line
@@ -424,7 +424,6 @@ static void amd_pmu_enable_counter(int idx, u64 config) 
{

	struct cpu_hw_counters *cpuc = &__get_cpu_var(cpu_hw_counters);



	set_bit(idx, cpuc->active);

	if (cpuc->enabled)

		config |= ARCH_PERFMON_EVENTSEL0_ENABLE;
@@ -446,9 +445,6 @@ static void intel_pmu_disable_counter(int idx, u64 config) 


static void amd_pmu_disable_counter(int idx, u64 config)

{

	struct cpu_hw_counters *cpuc = &__get_cpu_var(cpu_hw_counters);



	clear_bit(idx, cpuc->active);

	wrmsrl(MSR_K7_EVNTSEL0 + idx, config);



}
@@ -633,10 +629,7 @@ static int x86_pmu_enable(struct perf_counter *counter) 
	__x86_pmu_disable(counter, hwc, idx);



	cpuc->counters[idx] = counter;

	/*

	 * Make it visible before enabling the hw:

	 */

	barrier();

	set_bit(idx, cpuc->active);



	x86_perf_counter_set_period(counter, hwc, idx);

	__x86_pmu_enable(counter, hwc, idx);
@@ -700,10 +693,13 @@ static void x86_pmu_disable(struct perf_counter *counter) 
	struct hw_perf_counter *hwc = &counter->hw;

	unsigned int idx = hwc->idx;



	/*

	 * Must be done before we disable, otherwise the nmi handler

	 * could reenable again:

	 */

	clear_bit(idx, cpuc->active);

	__x86_pmu_disable(counter, hwc, idx);



	clear_bit(idx, cpuc->used);

	cpuc->counters[idx] = NULL;

	/*

	 * Make sure the cleared pointer becomes visible before we

	 * (potentially) free the counter:
@@ -715,6 +711,8 @@ static void x86_pmu_disable(struct perf_counter *counter) 
	 * that we are disabling:

	 */

	x86_perf_counter_update(counter, hwc, idx);

	cpuc->counters[idx] = NULL;

	clear_bit(idx, cpuc->used);

}



/*
@@ -763,7 +761,7 @@ static int intel_pmu_handle_irq(struct pt_regs *regs, int nmi) 
		struct perf_counter *counter = cpuc->counters[bit];



		clear_bit(bit, (unsigned long *) &status);

		if (!counter)

		if (!test_bit(bit, cpuc->active))

			continue;



		intel_pmu_save_and_restart(counter);