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>

diff --git a/arch/x86/kernel/cpu/perf_event_intel_ds.c b/arch/x86/kernel/cpu/perf_event_intel_ds.c
index 1bc1351..14d98bd 100644 (file)
--- 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;
        }