Commit c079c791 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

perf, amd: Remove the nb lock 



Since all the hotplug stuff is serialized by the hotplug mutex,
do away with the amd_nb_lock.

Cc: Stephane Eranian <eranian@google.com>
Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent b38aa896

arch/x86/kernel/cpu/perf_event_amd.c

+3 −13
Original line number Diff line number Diff line 
#ifdef CONFIG_CPU_SUP_AMD



static DEFINE_RAW_SPINLOCK(amd_nb_lock);



static __initconst const u64 amd_hw_cache_event_ids

				[PERF_COUNT_HW_CACHE_MAX]

				[PERF_COUNT_HW_CACHE_OP_MAX]
@@ -275,7 +273,7 @@ done: 
	return &emptyconstraint;

}



static struct amd_nb *amd_alloc_nb(int cpu, int nb_id)

static struct amd_nb *amd_alloc_nb(int cpu)

{

	struct amd_nb *nb;

	int i;
@@ -285,7 +283,7 @@ static struct amd_nb *amd_alloc_nb(int cpu, int nb_id) 
	if (!nb)

		return NULL;



	nb->nb_id = nb_id;

	nb->nb_id = -1;



	/*

	 * initialize all possible NB constraints
@@ -306,7 +304,7 @@ static int amd_pmu_cpu_prepare(int cpu) 
	if (boot_cpu_data.x86_max_cores < 2)

		return NOTIFY_OK;



	cpuc->amd_nb = amd_alloc_nb(cpu, -1);

	cpuc->amd_nb = amd_alloc_nb(cpu);

	if (!cpuc->amd_nb)

		return NOTIFY_BAD;
@@ -325,8 +323,6 @@ static void amd_pmu_cpu_starting(int cpu) 
	nb_id = amd_get_nb_id(cpu);

	WARN_ON_ONCE(nb_id == BAD_APICID);



	raw_spin_lock(&amd_nb_lock);



	for_each_online_cpu(i) {

		nb = per_cpu(cpu_hw_events, i).amd_nb;

		if (WARN_ON_ONCE(!nb))
@@ -341,8 +337,6 @@ static void amd_pmu_cpu_starting(int cpu) 


	cpuc->amd_nb->nb_id = nb_id;

	cpuc->amd_nb->refcnt++;



	raw_spin_unlock(&amd_nb_lock);

}



static void amd_pmu_cpu_dead(int cpu)
@@ -354,8 +348,6 @@ static void amd_pmu_cpu_dead(int cpu) 


	cpuhw = &per_cpu(cpu_hw_events, cpu);



	raw_spin_lock(&amd_nb_lock);



	if (cpuhw->amd_nb) {

		struct amd_nb *nb = cpuhw->amd_nb;
@@ -364,8 +356,6 @@ static void amd_pmu_cpu_dead(int cpu) 


		cpuhw->amd_nb = NULL;

	}



	raw_spin_unlock(&amd_nb_lock);

}



static __initconst const struct x86_pmu amd_pmu = {

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