[PATCH 3/7] perf, x86: Extract DS alloc/free functions

From: Peter Zijlstra
Date: Tue Oct 19 2010 - 09:56:18 EST


Again, mostly a cleanup to unclutter the reserve_ds_buffer() code.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
LKML-Reference: <new-submission>
---
arch/x86/kernel/cpu/perf_event_intel_ds.c | 40 +++++++++++++++++++-----------
1 file changed, 26 insertions(+), 14 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
@@ -148,6 +148,30 @@ static void release_bts_buffer(int cpu)
ds->bts_buffer_base = 0;
}

+static int alloc_ds_buffer(int cpu)
+{
+ struct debug_store *ds;
+
+ ds = kzalloc(sizeof(*ds), GFP_KERNEL);
+ if (unlikely(!ds))
+ return -ENOMEM;
+
+ per_cpu(cpu_hw_events, cpu).ds = ds;
+
+ return 0;
+}
+
+static void release_ds_buffer(int cpu)
+{
+ struct debug_store *ds = per_cpu(cpu_hw_events, cpu).ds;
+
+ if (!ds)
+ return;
+
+ per_cpu(cpu_hw_events, cpu).ds = NULL;
+ kfree(ds);
+}
+
static void release_ds_buffers(void)
{
int cpu;
@@ -160,16 +184,9 @@ static void release_ds_buffers(void)
fini_debug_store_on_cpu(cpu);

for_each_possible_cpu(cpu) {
- struct debug_store *ds = per_cpu(cpu_hw_events, cpu).ds;
-
- if (!ds)
- continue;
-
release_pebs_buffer(cpu);
release_bts_buffer(cpu);
-
- per_cpu(cpu_hw_events, cpu).ds = NULL;
- kfree(ds);
+ release_ds_buffer(cpu);
}
put_online_cpus();
}
@@ -184,13 +201,8 @@ static int reserve_ds_buffers(void)
get_online_cpus();

for_each_possible_cpu(cpu) {
- struct debug_store *ds;
-
- err = -ENOMEM;
- ds = kzalloc(sizeof(*ds), GFP_KERNEL);
- if (unlikely(!ds))
+ if (alloc_ds_buffer(cpu))
break;
- per_cpu(cpu_hw_events, cpu).ds = ds;

if (alloc_bts_buffer(cpu))
break;


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