lkml.org 
[lkml]   [2010]   [Oct]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[RFC][PATCH 6/7] perf: use jump_label to optimize the scheduler hooks

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
---
include/linux/perf_event.h | 27 +++++++++++++++++++++++++--
kernel/perf_event.c | 24 +++++++++---------------
2 files changed, 34 insertions(+), 17 deletions(-)
Index: linux-2.6/include/linux/perf_event.h
===================================================================
--- linux-2.6.orig/include/linux/perf_event.h
+++ linux-2.6/include/linux/perf_event.h
@@ -487,6 +487,7 @@ struct perf_guest_info_callbacks {
#include <linux/ftrace.h>
#include <linux/cpu.h>
#include <linux/irq_work.h>
+#include <linux/jump_label_ref.h>
#include <asm/atomic.h>
#include <asm/local.h>

@@ -893,8 +894,30 @@ struct perf_output_handle {
extern int perf_pmu_register(struct pmu *pmu);
extern void perf_pmu_unregister(struct pmu *pmu);

-extern void perf_event_task_sched_in(struct task_struct *task);
-extern void perf_event_task_sched_out(struct task_struct *task, struct task_struct *next);
+extern void __perf_event_task_sched_in(struct task_struct *task);
+extern void __perf_event_task_sched_out(struct task_struct *task, struct task_struct *next);
+
+extern atomic_t perf_task_events;
+
+static inline void perf_event_task_sched_in(struct task_struct *task)
+{
+ JUMP_LABEL(&perf_task_events, have_events);
+ return;
+
+have_events:
+ __perf_event_task_sched_in(task);
+}
+
+static inline
+void perf_event_task_sched_out(struct task_struct *task, struct task_struct *next)
+{
+ JUMP_LABEL(&perf_task_events, have_events);
+ return;
+
+have_events:
+ __perf_event_task_sched_out(task, 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);
Index: linux-2.6/kernel/perf_event.c
===================================================================
--- linux-2.6.orig/kernel/perf_event.c
+++ linux-2.6/kernel/perf_event.c
@@ -34,7 +34,7 @@

#include <asm/irq_regs.h>

-static atomic_t nr_events __read_mostly;
+atomic_t perf_task_events __read_mostly;
static atomic_t nr_mmap_events __read_mostly;
static atomic_t nr_comm_events __read_mostly;
static atomic_t nr_task_events __read_mostly;
@@ -1251,8 +1251,8 @@ void perf_event_context_sched_out(struct
* 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)
+void __perf_event_task_sched_out(struct task_struct *task,
+ struct task_struct *next)
{
int ctxn;

@@ -1280,14 +1280,6 @@ static void task_ctx_sched_out(struct pe
/*
* Called with IRQs disabled
*/
-static void __perf_event_task_sched_out(struct perf_event_context *ctx)
-{
- task_ctx_sched_out(ctx, EVENT_ALL);
-}
-
-/*
- * Called with IRQs disabled
- */
static void cpu_ctx_sched_out(struct perf_cpu_context *cpuctx,
enum event_type_t event_type)
{
@@ -1434,7 +1426,7 @@ void perf_event_context_sched_in(struct
* 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 *task)
+void __perf_event_task_sched_in(struct task_struct *task)
{
struct perf_event_context *ctx;
int ctxn;
@@ -2150,7 +2142,8 @@ static void free_event(struct perf_event
irq_work_sync(&event->pending);

if (!event->parent) {
- atomic_dec(&nr_events);
+ if (event->attach_state & PERF_ATTACH_TASK)
+ jump_label_dec(&perf_task_events);
if (event->attr.mmap || event->attr.mmap_data)
atomic_dec(&nr_mmap_events);
if (event->attr.comm)
@@ -5286,7 +5279,8 @@ perf_event_alloc(struct perf_event_attr
event->pmu = pmu;

if (!event->parent) {
- atomic_inc(&nr_events);
+ if (event->attach_state & PERF_ATTACH_TASK)
+ jump_label_inc(&perf_task_events);
if (event->attr.mmap || event->attr.mmap_data)
atomic_inc(&nr_mmap_events);
if (event->attr.comm)
@@ -5781,7 +5775,7 @@ static void perf_event_exit_task_context
* our context.
*/
child_ctx = child->perf_event_ctxp[ctxn];
- __perf_event_task_sched_out(child_ctx);
+ task_ctx_sched_out(child_ctx, EVENT_ALL);

/*
* Take the context lock here so that if find_get_context is



\
 
 \ /
  Last update: 2010-10-14 23:13    [from the cache]
©2003-2014 Jasper Spaans. hosted at Digital Ocean