perf events: Remove arg from perf sched hooks

Since we only ever schedule the local cpu, there is no need to pass the
cpu number to the perf sched hooks.

This micro-optimizes things a bit.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

3 files changed, 23 insertions, 22 deletions

diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index c66b34f75eea..a494e7501292 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -746,10 +746,10 @@ extern int perf_max_events;
 
 extern const struct pmu *hw_perf_event_init(struct perf_event *event);
 
-extern void perf_event_task_sched_in(struct task_struct *task, int cpu);
+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, int cpu);
-extern void perf_event_task_tick(struct task_struct *task, int cpu);
+                                        struct task_struct *next);
+extern void perf_event_task_tick(struct task_struct *task);
 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);
@@ -870,12 +870,12 @@ extern void perf_event_enable(struct perf_event *event);
 extern void perf_event_disable(struct perf_event *event);
 #else
 static inline void
-perf_event_task_sched_in(struct task_struct *task, int cpu)             { }
+perf_event_task_sched_in(struct task_struct *task)                      { }
 static inline void
 perf_event_task_sched_out(struct task_struct *task,
-                            struct task_struct *next, int cpu)          { }
+                            struct task_struct *next)                   { }
 static inline void
-perf_event_task_tick(struct task_struct *task, int cpu)                 { }
+perf_event_task_tick(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/perf_event.c b/kernel/perf_event.c
index 03cc061398d1..099bd662daa6 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -1170,9 +1170,9 @@ static void perf_event_sync_stat(struct perf_event_context *ctx,
  * not restart the event.
  */
 void perf_event_task_sched_out(struct task_struct *task,
-                                 struct task_struct *next, int cpu)
+                                 struct task_struct *next)
 {
-        struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu);
+        struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
         struct perf_event_context *ctx = task->perf_event_ctxp;
         struct perf_event_context *next_ctx;
         struct perf_event_context *parent;
@@ -1252,8 +1252,9 @@ static void perf_event_cpu_sched_out(struct perf_cpu_context *cpuctx)
 
 static void
 __perf_event_sched_in(struct perf_event_context *ctx,
-                        struct perf_cpu_context *cpuctx, int cpu)
+                        struct perf_cpu_context *cpuctx)
 {
+        int cpu = smp_processor_id();
         struct perf_event *event;
         int can_add_hw = 1;
 
@@ -1326,24 +1327,24 @@ __perf_event_sched_in(struct perf_event_context *ctx,
  * 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, int cpu)
+void perf_event_task_sched_in(struct task_struct *task)
 {
-        struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu);
+        struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
         struct perf_event_context *ctx = task->perf_event_ctxp;
 
         if (likely(!ctx))
                 return;
         if (cpuctx->task_ctx == ctx)
                 return;
-        __perf_event_sched_in(ctx, cpuctx, cpu);
+        __perf_event_sched_in(ctx, cpuctx);
         cpuctx->task_ctx = ctx;
 }
 
-static void perf_event_cpu_sched_in(struct perf_cpu_context *cpuctx, int cpu)
+static void perf_event_cpu_sched_in(struct perf_cpu_context *cpuctx)
 {
         struct perf_event_context *ctx = &cpuctx->ctx;
 
-        __perf_event_sched_in(ctx, cpuctx, cpu);
+        __perf_event_sched_in(ctx, cpuctx);
 }
 
 #define MAX_INTERRUPTS (~0ULL)
@@ -1461,7 +1462,7 @@ static void rotate_ctx(struct perf_event_context *ctx)
         raw_spin_unlock(&ctx->lock);
 }
 
-void perf_event_task_tick(struct task_struct *curr, int cpu)
+void perf_event_task_tick(struct task_struct *curr)
 {
         struct perf_cpu_context *cpuctx;
         struct perf_event_context *ctx;
@@ -1469,7 +1470,7 @@ void perf_event_task_tick(struct task_struct *curr, int cpu)
         if (!atomic_read(&nr_events))
                 return;
 
-        cpuctx = &per_cpu(perf_cpu_context, cpu);
+        cpuctx = &__get_cpu_var(perf_cpu_context);
         ctx = curr->perf_event_ctxp;
 
         perf_ctx_adjust_freq(&cpuctx->ctx);
@@ -1484,9 +1485,9 @@ void perf_event_task_tick(struct task_struct *curr, int cpu)
         if (ctx)
                 rotate_ctx(ctx);
 
-        perf_event_cpu_sched_in(cpuctx, cpu);
+        perf_event_cpu_sched_in(cpuctx);
         if (ctx)
-                perf_event_task_sched_in(curr, cpu);
+                perf_event_task_sched_in(curr);
 }
 
 /*
@@ -1527,7 +1528,7 @@ static void perf_event_enable_on_exec(struct task_struct *task)
 
         raw_spin_unlock(&ctx->lock);
 
-        perf_event_task_sched_in(task, smp_processor_id());
+        perf_event_task_sched_in(task);
  out:
         local_irq_restore(flags);
 }
diff --git a/kernel/sched.c b/kernel/sched.c
index 18cceeecce35..d6527ac0f6e7 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -2752,7 +2752,7 @@ static void finish_task_switch(struct rq *rq, struct task_struct *prev)
          */
         prev_state = prev->state;
         finish_arch_switch(prev);
-        perf_event_task_sched_in(current, cpu_of(rq));
+        perf_event_task_sched_in(current);
         finish_lock_switch(rq, prev);
 
         fire_sched_in_preempt_notifiers(current);
@@ -5266,7 +5266,7 @@ void scheduler_tick(void)
         curr->sched_class->task_tick(rq, curr, 0);
         raw_spin_unlock(&rq->lock);
 
-        perf_event_task_tick(curr, cpu);
+        perf_event_task_tick(curr);
 
 #ifdef CONFIG_SMP
         rq->idle_at_tick = idle_cpu(cpu);
@@ -5480,7 +5480,7 @@ need_resched_nonpreemptible:
 
         if (likely(prev != next)) {
                 sched_info_switch(prev, next);
-                perf_event_task_sched_out(prev, next, cpu);
+                perf_event_task_sched_out(prev, next);
 
                 rq->nr_switches++;
                 rq->curr = next;