perf, x86: Extract PEBS/BTS allocation functions

Mostly a cleanup.. it reduces code indentation and makes the code flow
of reserve_ds_buffers() clearer.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Stephane Eranian <eranian@google.com>
LKML-Reference: <20101019134808.253453452@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 56 insertions, 34 deletions

diff --git a/arch/x86/kernel/cpu/perf_event_intel_ds.c b/arch/x86/kernel/cpu/perf_event_intel_ds.c
index 1bc13518dd59..14d98bd52055 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_ds.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_ds.c
@@ -74,6 +74,32 @@ static void fini_debug_store_on_cpu(int cpu)
         wrmsr_on_cpu(cpu, MSR_IA32_DS_AREA, 0, 0);
 }
 
+static int alloc_pebs_buffer(int cpu)
+{
+        struct debug_store *ds = per_cpu(cpu_hw_events, cpu).ds;
+        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);
+        if (unlikely(!buffer))
+                return -ENOMEM;
+
+        max = PEBS_BUFFER_SIZE / x86_pmu.pebs_record_size;
+
+        ds->pebs_buffer_base = (u64)(unsigned long)buffer;
+        ds->pebs_index = ds->pebs_buffer_base;
+        ds->pebs_absolute_maximum = ds->pebs_buffer_base +
+                max * x86_pmu.pebs_record_size;
+
+        ds->pebs_interrupt_threshold = ds->pebs_buffer_base +
+                thresh * x86_pmu.pebs_record_size;
+
+        return 0;
+}
+
 static void release_pebs_buffer(int cpu)
 {
         struct debug_store *ds = per_cpu(cpu_hw_events, cpu).ds;
@@ -85,6 +111,32 @@ static void release_pebs_buffer(int cpu)
         ds->pebs_buffer_base = 0;
 }
 
+static int alloc_bts_buffer(int cpu)
+{
+        struct debug_store *ds = per_cpu(cpu_hw_events, cpu).ds;
+        int max, thresh;
+        void *buffer;
+
+        if (!x86_pmu.bts)
+                return 0;
+
+        buffer = kzalloc(BTS_BUFFER_SIZE, GFP_KERNEL);
+        if (unlikely(!buffer))
+                return -ENOMEM;
+
+        max = BTS_BUFFER_SIZE / BTS_RECORD_SIZE;
+        thresh = max / 16;
+
+        ds->bts_buffer_base = (u64)(unsigned long)buffer;
+        ds->bts_index = ds->bts_buffer_base;
+        ds->bts_absolute_maximum = ds->bts_buffer_base +
+                max * BTS_RECORD_SIZE;
+        ds->bts_interrupt_threshold = ds->bts_absolute_maximum -
+                thresh * BTS_RECORD_SIZE;
+
+        return 0;
+}
+
 static void release_bts_buffer(int cpu)
 {
         struct debug_store *ds = per_cpu(cpu_hw_events, cpu).ds;
@@ -133,8 +185,6 @@ static int reserve_ds_buffers(void)
 
         for_each_possible_cpu(cpu) {
                 struct debug_store *ds;
-                void *buffer;
-                int max, thresh;
 
                 err = -ENOMEM;
                 ds = kzalloc(sizeof(*ds), GFP_KERNEL);
@@ -142,39 +192,11 @@ static int reserve_ds_buffers(void)
                         break;
                 per_cpu(cpu_hw_events, cpu).ds = ds;
 
-                if (x86_pmu.bts) {
-                        buffer = kzalloc(BTS_BUFFER_SIZE, GFP_KERNEL);
-                        if (unlikely(!buffer))
-                                break;
-
-                        max = BTS_BUFFER_SIZE / BTS_RECORD_SIZE;
-                        thresh = max / 16;
-
-                        ds->bts_buffer_base = (u64)(unsigned long)buffer;
-                        ds->bts_index = ds->bts_buffer_base;
-                        ds->bts_absolute_maximum = ds->bts_buffer_base +
-                                max * BTS_RECORD_SIZE;
-                        ds->bts_interrupt_threshold = ds->bts_absolute_maximum -
-                                thresh * BTS_RECORD_SIZE;
-                }
+                if (alloc_bts_buffer(cpu))
+                        break;
 
-                if (x86_pmu.pebs) {
-                        buffer = kzalloc(PEBS_BUFFER_SIZE, GFP_KERNEL);
-                        if (unlikely(!buffer))
-                                break;
-
-                        max = PEBS_BUFFER_SIZE / x86_pmu.pebs_record_size;
-
-                        ds->pebs_buffer_base = (u64)(unsigned long)buffer;
-                        ds->pebs_index = ds->pebs_buffer_base;
-                        ds->pebs_absolute_maximum = ds->pebs_buffer_base +
-                                max * x86_pmu.pebs_record_size;
-                        /*
-                         * Always use single record PEBS
-                         */
-                        ds->pebs_interrupt_threshold = ds->pebs_buffer_base +
-                                x86_pmu.pebs_record_size;
-                }
+                if (alloc_pebs_buffer(cpu))
+                        break;
 
                 err = 0;
         }