perf: Remove the perf_output_begin(.sample) argument
Peter Zijlstra [Mon, 27 Jun 2011 14:47:16 +0000 (16:47 +0200)]
Since only samples call perf_output_sample() its much saner (and more
correct) to put the sample logic in there than in the
perf_output_begin()/perf_output_end() pair.

Saves a useless argument, reduces conditionals and shrinks
struct perf_output_handle, win!

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-2crpvsx3cqu67q3zqjbnlpsc@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/kernel/cpu/perf_event_intel_ds.c
include/linux/perf_event.h
kernel/events/core.c
kernel/events/ring_buffer.c

index 0941f93..1b1ef3a 100644 (file)
@@ -340,7 +340,7 @@ static int intel_pmu_drain_bts_buffer(void)
         */
        perf_prepare_sample(&header, &data, event, &regs);
 
-       if (perf_output_begin(&handle, event, header.size * (top - at), 1))
+       if (perf_output_begin(&handle, event, header.size * (top - at)))
                return 1;
 
        for (; at < top; at++) {
index 0946a8b..771b0b2 100644 (file)
@@ -925,7 +925,6 @@ struct perf_output_handle {
        unsigned long                   size;
        void                            *addr;
        int                             page;
-       int                             sample;
 };
 
 #ifdef CONFIG_PERF_EVENTS
@@ -1117,8 +1116,7 @@ extern void perf_bp_event(struct perf_event *event, void *data);
 #endif
 
 extern int perf_output_begin(struct perf_output_handle *handle,
-                            struct perf_event *event, unsigned int size,
-                            int sample);
+                            struct perf_event *event, unsigned int size);
 extern void perf_output_end(struct perf_output_handle *handle);
 extern void perf_output_copy(struct perf_output_handle *handle,
                             const void *buf, unsigned int len);
index dbd1ca7..81de28d 100644 (file)
@@ -3928,6 +3928,20 @@ void perf_output_sample(struct perf_output_handle *handle,
                        perf_output_put(handle, raw);
                }
        }
+
+       if (!event->attr.watermark) {
+               int wakeup_events = event->attr.wakeup_events;
+
+               if (wakeup_events) {
+                       struct ring_buffer *rb = handle->rb;
+                       int events = local_inc_return(&rb->events);
+
+                       if (events >= wakeup_events) {
+                               local_sub(wakeup_events, &rb->events);
+                               local_inc(&rb->wakeup);
+                       }
+               }
+       }
 }
 
 void perf_prepare_sample(struct perf_event_header *header,
@@ -3984,7 +3998,7 @@ static void perf_event_output(struct perf_event *event,
 
        perf_prepare_sample(&header, data, event, regs);
 
-       if (perf_output_begin(&handle, event, header.size, 1))
+       if (perf_output_begin(&handle, event, header.size))
                goto exit;
 
        perf_output_sample(&handle, &header, data, event);
@@ -4024,7 +4038,7 @@ perf_event_read_event(struct perf_event *event,
        int ret;
 
        perf_event_header__init_id(&read_event.header, &sample, event);
-       ret = perf_output_begin(&handle, event, read_event.header.size, 0);
+       ret = perf_output_begin(&handle, event, read_event.header.size);
        if (ret)
                return;
 
@@ -4067,7 +4081,7 @@ static void perf_event_task_output(struct perf_event *event,
        perf_event_header__init_id(&task_event->event_id.header, &sample, event);
 
        ret = perf_output_begin(&handle, event,
-                               task_event->event_id.header.size, 0);
+                               task_event->event_id.header.size);
        if (ret)
                goto out;
 
@@ -4204,7 +4218,7 @@ static void perf_event_comm_output(struct perf_event *event,
 
        perf_event_header__init_id(&comm_event->event_id.header, &sample, event);
        ret = perf_output_begin(&handle, event,
-                               comm_event->event_id.header.size, 0);
+                               comm_event->event_id.header.size);
 
        if (ret)
                goto out;
@@ -4351,7 +4365,7 @@ static void perf_event_mmap_output(struct perf_event *event,
 
        perf_event_header__init_id(&mmap_event->event_id.header, &sample, event);
        ret = perf_output_begin(&handle, event,
-                               mmap_event->event_id.header.size, 0);
+                               mmap_event->event_id.header.size);
        if (ret)
                goto out;
 
@@ -4546,7 +4560,7 @@ static void perf_log_throttle(struct perf_event *event, int enable)
        perf_event_header__init_id(&throttle_event.header, &sample, event);
 
        ret = perf_output_begin(&handle, event,
-                               throttle_event.header.size, 0);
+                               throttle_event.header.size);
        if (ret)
                return;
 
index 8b3b736..a2a2920 100644 (file)
@@ -98,8 +98,7 @@ out:
 }
 
 int perf_output_begin(struct perf_output_handle *handle,
-                     struct perf_event *event, unsigned int size,
-                     int sample)
+                     struct perf_event *event, unsigned int size)
 {
        struct ring_buffer *rb;
        unsigned long tail, offset, head;
@@ -124,7 +123,6 @@ int perf_output_begin(struct perf_output_handle *handle,
 
        handle->rb      = rb;
        handle->event   = event;
-       handle->sample  = sample;
 
        if (!rb->nr_pages)
                goto out;
@@ -192,21 +190,6 @@ void perf_output_copy(struct perf_output_handle *handle,
 
 void perf_output_end(struct perf_output_handle *handle)
 {
-       struct perf_event *event = handle->event;
-       struct ring_buffer *rb = handle->rb;
-
-       if (handle->sample && !event->attr.watermark) {
-               int wakeup_events = event->attr.wakeup_events;
-
-               if (wakeup_events) {
-                       int events = local_inc_return(&rb->events);
-                       if (events >= wakeup_events) {
-                               local_sub(wakeup_events, &rb->events);
-                               local_inc(&rb->wakeup);
-                       }
-               }
-       }
-
        perf_output_put_handle(handle);
        rcu_read_unlock();
 }