[tip:perf/core] perf_event: x86: Deduplicate the disable code

tip-bot for Peter Zijlstra
2010-01-29T09:30:36Z

Commit-ID: 2e8418736dff9c6fdadb2f87dcc2087cebf32167
Gitweb: http://git.kernel.org/tip/2e8418736dff9c6fdadb2f87dcc2087cebf32167
Author: Peter Zijlstra <a.p.zijlstra@chello.nl>
AuthorDate: Mon, 25 Jan 2010 15:58:43 +0100
Committer: Ingo Molnar <mingo@elte.hu>
CommitDate: Fri, 29 Jan 2010 09:01:45 +0100

perf_event: x86: Deduplicate the disable code

Share the meat of the x86_pmu_disable() code with hw_perf_enable().

Also remove the barrier() from that code, since I could not convince
myself we actually need it.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
arch/x86/kernel/cpu/perf_event.c | 29 +++++++++++++----------------
1 files changed, 13 insertions(+), 16 deletions(-)

diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index fdbe248..07fa0c2 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -1401,6 +1401,8 @@ static inline void x86_assign_hw_event(struct perf_event *event,
}
}

+static void __x86_pmu_disable(struct perf_event *event, struct cpu_hw_events *cpuc);
+
void hw_perf_enable(void)
{
struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
@@ -1426,13 +1428,7 @@ void hw_perf_enable(void)
if (hwc->idx == -1 || hwc->idx == cpuc->assign[i])
continue;

- x86_pmu.disable(hwc, hwc->idx);
-
- clear_bit(hwc->idx, cpuc->active_mask);
- barrier();
- cpuc->events[hwc->idx] = NULL;
-
- x86_perf_event_update(event, hwc, hwc->idx);
+ __x86_pmu_disable(event, cpuc);

hwc->idx = -1;
}
@@ -1822,11 +1818,10 @@ static void intel_pmu_drain_bts_buffer(struct cpu_hw_events *cpuc)
event->pending_kill = POLL_IN;
}

-static void x86_pmu_disable(struct perf_event *event)
+static void __x86_pmu_disable(struct perf_event *event, struct cpu_hw_events *cpuc)
{
- struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
struct hw_perf_event *hwc = &event->hw;
- int i, idx = hwc->idx;
+ int idx = hwc->idx;

/*
* Must be done before we disable, otherwise the nmi handler
@@ -1836,12 +1831,6 @@ static void x86_pmu_disable(struct perf_event *event)
x86_pmu.disable(hwc, idx);

/*
- * Make sure the cleared pointer becomes visible before we
- * (potentially) free the event:
- */
- barrier();
-
- /*
* Drain the remaining delta count out of a event
* that we are disabling:
*/
@@ -1852,6 +1841,14 @@ static void x86_pmu_disable(struct perf_event *event)
intel_pmu_drain_bts_buffer(cpuc);

cpuc->events[idx] = NULL;
+}
+
+static void x86_pmu_disable(struct perf_event *event)
+{
+ struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+ int i;
+
+ __x86_pmu_disable(event, cpuc);

for (i = 0; i < cpuc->n_events; i++) {
if (event == cpuc->event_list[i]) {