[PATCH 7/7] perf, x86: Use NUMA aware allocations for PEBS/BTS/DS allocations

From: Peter Zijlstra
Date: Tue Oct 19 2010 - 09:56:08 EST


For performance reasons its best to use NODE local memory for per-cpu buffers.

This logic comes from a much larger patch proposed by Stephane.

Suggested-by: Stephane Eranian <eranian@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
LKML-Reference: <new-submission>
---
arch/x86/kernel/cpu/perf_event_intel_ds.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)

Index: linux-2.6/arch/x86/kernel/cpu/perf_event_intel_ds.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/perf_event_intel_ds.c
+++ linux-2.6/arch/x86/kernel/cpu/perf_event_intel_ds.c
@@ -77,13 +77,14 @@ static void fini_debug_store_on_cpu(int
static int alloc_pebs_buffer(int cpu)
{
struct debug_store *ds = per_cpu(cpu_hw_events, cpu).ds;
+ int node = cpu_to_node(cpu);
int max, thresh = 1; /* always use a single PEBS record */
void *buffer;

if (!x86_pmu.pebs)
return 0;

- buffer = kzalloc(PEBS_BUFFER_SIZE, GFP_KERNEL);
+ buffer = kmalloc_node(PEBS_BUFFER_SIZE, GFP_KERNEL | __GFP_ZERO, node);
if (unlikely(!buffer))
return -ENOMEM;

@@ -114,13 +115,14 @@ static void release_pebs_buffer(int cpu)
static int alloc_bts_buffer(int cpu)
{
struct debug_store *ds = per_cpu(cpu_hw_events, cpu).ds;
+ int node = cpu_to_node(cpu);
int max, thresh;
void *buffer;

if (!x86_pmu.bts)
return 0;

- buffer = kzalloc(BTS_BUFFER_SIZE, GFP_KERNEL);
+ buffer = kmalloc_node(BTS_BUFFER_SIZE, GFP_KERNEL | __GFP_ZERO, node);
if (unlikely(!buffer))
return -ENOMEM;

@@ -150,9 +152,10 @@ static void release_bts_buffer(int cpu)

static int alloc_ds_buffer(int cpu)
{
+ int node = cpu_to_node(cpu);
struct debug_store *ds;

- ds = kzalloc(sizeof(*ds), GFP_KERNEL);
+ ds = kmalloc_node(sizeof(*ds), GFP_KERNEL | __GFP_ZERO, node);
if (unlikely(!ds))
return -ENOMEM;



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