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Commit fe4a3308 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
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perf, x86: Implement user-space RDPMC support, to allow fast, user-space... 


perf, x86: Implement user-space RDPMC support, to allow fast, user-space access to self-monitoring counters

Implement a correct pmu::event_idx for the x86 counter index rules and
set CR4.PCE on CPU_STARTING.

Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Cc: Arun Sharma <asharma@fb.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: http://lkml.kernel.org/n/tip-mwxab34dibqgzk5zywutfnha@git.kernel.org


Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 365a4038

arch/x86/kernel/cpu/perf_event.c

+15 −0
Original line number Diff line number Diff line
@@ -1210,6 +1210,7 @@ x86_pmu_notifier(struct notifier_block *self, unsigned long action, void *hcpu) 
		break;



	case CPU_STARTING:

		set_in_cr4(X86_CR4_PCE);

		if (x86_pmu.cpu_starting)

			x86_pmu.cpu_starting(cpu);

		break;
@@ -1542,6 +1543,18 @@ static int x86_pmu_event_init(struct perf_event *event) 
	return err;

}



static int x86_pmu_event_idx(struct perf_event *event)

{

	int idx = event->hw.idx;



	if (x86_pmu.num_counters_fixed && idx >= X86_PMC_IDX_FIXED) {

		idx -= X86_PMC_IDX_FIXED;

		idx |= 1 << 30;

	}



	return idx + 1;

}



static struct pmu pmu = {

	.pmu_enable	= x86_pmu_enable,

	.pmu_disable	= x86_pmu_disable,
@@ -1557,6 +1570,8 @@ static struct pmu pmu = { 
	.start_txn	= x86_pmu_start_txn,

	.cancel_txn	= x86_pmu_cancel_txn,

	.commit_txn	= x86_pmu_commit_txn,



	.event_idx	= x86_pmu_event_idx,

};



/*