[tip:perf/core] sched, perf: Use a single callback into the scheduler
From: tip-bot for Peter Zijlstra
Date: Wed May 09 2012 - 10:40:10 EST
Commit-ID: cb04ff9ac424d0e689d9b612e9f73cb443ab4b7e
Gitweb: http://git.kernel.org/tip/cb04ff9ac424d0e689d9b612e9f73cb443ab4b7e
Author: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
AuthorDate: Tue, 8 May 2012 18:56:04 +0200
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Wed, 9 May 2012 15:23:17 +0200
sched, perf: Use a single callback into the scheduler
We can easily use a single callback for both sched-in and sched-out. This
reduces the code footprint in the scheduler path as well as removes
the PMU black spot otherwise present between the out and in callback.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Link: http://lkml.kernel.org/n/tip-o56ajxp1edwqg6x9d31wb805@xxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
include/linux/perf_event.h | 24 ++++++------------------
kernel/events/core.c | 14 ++++++++++----
kernel/sched/core.c | 9 +--------
3 files changed, 17 insertions(+), 30 deletions(-)
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index f325786..8adf70e 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -1084,10 +1084,8 @@ extern void perf_pmu_unregister(struct pmu *pmu);
extern int perf_num_counters(void);
extern const char *perf_pmu_name(void);
-extern void __perf_event_task_sched_in(struct task_struct *prev,
- struct task_struct *task);
-extern void __perf_event_task_sched_out(struct task_struct *prev,
- struct task_struct *next);
+extern void __perf_event_task_sched(struct task_struct *prev,
+ struct task_struct *next);
extern int perf_event_init_task(struct task_struct *child);
extern void perf_event_exit_task(struct task_struct *child);
extern void perf_event_free_task(struct task_struct *task);
@@ -1207,20 +1205,13 @@ perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr)
extern struct static_key_deferred perf_sched_events;
-static inline void perf_event_task_sched_in(struct task_struct *prev,
+static inline void perf_event_task_sched(struct task_struct *prev,
struct task_struct *task)
{
- if (static_key_false(&perf_sched_events.key))
- __perf_event_task_sched_in(prev, task);
-}
-
-static inline void perf_event_task_sched_out(struct task_struct *prev,
- struct task_struct *next)
-{
perf_sw_event(PERF_COUNT_SW_CONTEXT_SWITCHES, 1, NULL, 0);
if (static_key_false(&perf_sched_events.key))
- __perf_event_task_sched_out(prev, next);
+ __perf_event_task_sched(prev, task);
}
extern void perf_event_mmap(struct vm_area_struct *vma);
@@ -1295,11 +1286,8 @@ extern void perf_event_disable(struct perf_event *event);
extern void perf_event_task_tick(void);
#else
static inline void
-perf_event_task_sched_in(struct task_struct *prev,
- struct task_struct *task) { }
-static inline void
-perf_event_task_sched_out(struct task_struct *prev,
- struct task_struct *next) { }
+perf_event_task_sched(struct task_struct *prev,
+ struct task_struct *task) { }
static inline int perf_event_init_task(struct task_struct *child) { return 0; }
static inline void perf_event_exit_task(struct task_struct *child) { }
static inline void perf_event_free_task(struct task_struct *task) { }
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 00c58df..e82c7a1 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -2039,8 +2039,8 @@ static void perf_event_context_sched_out(struct task_struct *task, int ctxn,
* accessing the event control register. If a NMI hits, then it will
* not restart the event.
*/
-void __perf_event_task_sched_out(struct task_struct *task,
- struct task_struct *next)
+static void __perf_event_task_sched_out(struct task_struct *task,
+ struct task_struct *next)
{
int ctxn;
@@ -2279,8 +2279,8 @@ static void perf_branch_stack_sched_in(struct task_struct *prev,
* accessing the event control register. If a NMI hits, then it will
* keep the event running.
*/
-void __perf_event_task_sched_in(struct task_struct *prev,
- struct task_struct *task)
+static void __perf_event_task_sched_in(struct task_struct *prev,
+ struct task_struct *task)
{
struct perf_event_context *ctx;
int ctxn;
@@ -2305,6 +2305,12 @@ void __perf_event_task_sched_in(struct task_struct *prev,
perf_branch_stack_sched_in(prev, task);
}
+void __perf_event_task_sched(struct task_struct *prev, struct task_struct *next)
+{
+ __perf_event_task_sched_out(prev, next);
+ __perf_event_task_sched_in(prev, next);
+}
+
static u64 perf_calculate_period(struct perf_event *event, u64 nsec, u64 count)
{
u64 frequency = event->attr.sample_freq;
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 4603b9d..5c692a0 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1913,7 +1913,7 @@ prepare_task_switch(struct rq *rq, struct task_struct *prev,
struct task_struct *next)
{
sched_info_switch(prev, next);
- perf_event_task_sched_out(prev, next);
+ perf_event_task_sched(prev, next);
fire_sched_out_preempt_notifiers(prev, next);
prepare_lock_switch(rq, next);
prepare_arch_switch(next);
@@ -1956,13 +1956,6 @@ static void finish_task_switch(struct rq *rq, struct task_struct *prev)
*/
prev_state = prev->state;
finish_arch_switch(prev);
-#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
- local_irq_disable();
-#endif /* __ARCH_WANT_INTERRUPTS_ON_CTXSW */
- perf_event_task_sched_in(prev, current);
-#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
- local_irq_enable();
-#endif /* __ARCH_WANT_INTERRUPTS_ON_CTXSW */
finish_lock_switch(rq, prev);
finish_arch_post_lock_switch();
--
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