[tip:perf/core] perf, amd: Remove the nb lock

tip-bot for Peter Zijlstra
2010-12-08T20:42:47Z

Commit-ID: c079c791c5a0627fc7b752d31d72e274e0596ba8
Gitweb: http://git.kernel.org/tip/c079c791c5a0627fc7b752d31d72e274e0596ba8
Author: Peter Zijlstra <a.p.zijlstra@chello.nl>
AuthorDate: Thu, 25 Nov 2010 08:56:17 +0100
Committer: Ingo Molnar <mingo@elte.hu>
CommitDate: Wed, 8 Dec 2010 20:16:30 +0100

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: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
arch/x86/kernel/cpu/perf_event_amd.c | 16 +++-------------
1 files changed, 3 insertions(+), 13 deletions(-)

diff --git a/arch/x86/kernel/cpu/perf_event_amd.c b/arch/x86/kernel/cpu/perf_event_amd.c
index e421b8c..67e2202 100644
--- a/arch/x86/kernel/cpu/perf_event_amd.c
+++ b/arch/x86/kernel/cpu/perf_event_amd.c
@@ -1,7 +1,5 @@
#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 = {