[tip:perf/urgent] perf, x86: Extract PEBS/BTS allocation functions

From: tip-bot for Peter Zijlstra
Date: Fri Oct 22 2010 - 09:03:27 EST


Commit-ID: 5ee25c87318fa3722026fd77089fa7ba0db8d447
Gitweb: http://git.kernel.org/tip/5ee25c87318fa3722026fd77089fa7ba0db8d447
Author: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
AuthorDate: Tue, 19 Oct 2010 14:15:04 +0200
Committer: Ingo Molnar <mingo@xxxxxxx>
CommitDate: Fri, 22 Oct 2010 14:18:25 +0200

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@xxxxxxxxx>
Acked-by: Stephane Eranian <eranian@xxxxxxxxxx>
LKML-Reference: <20101019134808.253453452@xxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
---
arch/x86/kernel/cpu/perf_event_intel_ds.c | 92 ++++++++++++++++++-----------
1 files changed, 57 insertions(+), 35 deletions(-)

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
--- 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;
}
--
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