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Commit 66d21901 authored by Alexander Shishkin's avatar Alexander Shishkin Committed by Ingo Molnar
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perf/x86/intel/pt: Move transaction start/stop to PMU start/stop callbacks 



As per AUX buffer management requirement, AUX output has to happen between
pmu::start and pmu::stop calls so that perf_event_stop() actually stops it
and therefore perf can free the AUX data after it has called pmu::stop.

This patch moves perf_aux_output_{begin,end} from pt_event_{add,del} to
pt_event_{start,stop}. As a bonus, we get rid of pt_buffer_is_full(),
which is already taken care of by perf_aux_output_begin() anyway.

Signed-off-by: default avatarAlexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: vince@deater.net
Link: http://lkml.kernel.org/r/1457098969-21595-5-git-send-email-alexander.shishkin@linux.intel.com


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent af5bb4ed

arch/x86/events/intel/pt.c

+27 −58
Original line number Original line Diff line number Diff line
@@ -905,26 +905,6 @@ static void pt_buffer_free_aux(void *data) 
	kfree(buf);

	kfree(buf);

}

}





/**

 * pt_buffer_is_full() - check if the buffer is full

 * @buf:	PT buffer.

 * @pt:		Per-cpu pt handle.

 *

 * If the user hasn't read data from the output region that aux_head

 * points to, the buffer is considered full: the user needs to read at

 * least this region and update aux_tail to point past it.

 */

static bool pt_buffer_is_full(struct pt_buffer *buf, struct pt *pt)

{

	if (buf->snapshot)

		return false;



	if (local_read(&buf->data_size) >= pt->handle.size)

		return true;



	return false;

}



/**

/**

 * intel_pt_interrupt() - PT PMI handler

 * intel_pt_interrupt() - PT PMI handler

 */

 */
@@ -989,20 +969,33 @@ void intel_pt_interrupt(void) 




static void pt_event_start(struct perf_event *event, int mode)

static void pt_event_start(struct perf_event *event, int mode)

{

{

	struct hw_perf_event *hwc = &event->hw;

	struct pt *pt = this_cpu_ptr(&pt_ctx);

	struct pt *pt = this_cpu_ptr(&pt_ctx);

	struct pt_buffer *buf = perf_get_aux(&pt->handle);

	struct pt_buffer *buf;





	if (!buf || pt_buffer_is_full(buf, pt)) {

	buf = perf_aux_output_begin(&pt->handle, event);

		event->hw.state = PERF_HES_STOPPED;

	if (!buf)

		return;

		goto fail_stop;



	pt_buffer_reset_offsets(buf, pt->handle.head);

	if (!buf->snapshot) {

		if (pt_buffer_reset_markers(buf, &pt->handle))

			goto fail_end_stop;

	}

	}





	ACCESS_ONCE(pt->handle_nmi) = 1;

	ACCESS_ONCE(pt->handle_nmi) = 1;

	event->hw.state = 0;

	hwc->state = 0;





	pt_config_buffer(buf->cur->table, buf->cur_idx,

	pt_config_buffer(buf->cur->table, buf->cur_idx,

			 buf->output_off);

			 buf->output_off);

	pt_config(event);

	pt_config(event);



	return;



fail_end_stop:

	perf_aux_output_end(&pt->handle, 0, true);

fail_stop:

	hwc->state = PERF_HES_STOPPED;

}

}





static void pt_event_stop(struct perf_event *event, int mode)

static void pt_event_stop(struct perf_event *event, int mode)
@@ -1035,19 +1028,7 @@ static void pt_event_stop(struct perf_event *event, int mode) 
		pt_handle_status(pt);

		pt_handle_status(pt);





		pt_update_head(pt);

		pt_update_head(pt);

	}

}





static void pt_event_del(struct perf_event *event, int mode)

{

	struct pt *pt = this_cpu_ptr(&pt_ctx);

	struct pt_buffer *buf;



	pt_event_stop(event, PERF_EF_UPDATE);



	buf = perf_get_aux(&pt->handle);



	if (buf) {

		if (buf->snapshot)

		if (buf->snapshot)

			pt->handle.head =

			pt->handle.head =

				local_xchg(&buf->data_size,

				local_xchg(&buf->data_size,
@@ -1057,9 +1038,13 @@ static void pt_event_del(struct perf_event *event, int mode) 
	}

	}

}

}





static void pt_event_del(struct perf_event *event, int mode)

{

	pt_event_stop(event, PERF_EF_UPDATE);

}



static int pt_event_add(struct perf_event *event, int mode)

static int pt_event_add(struct perf_event *event, int mode)

{

{

	struct pt_buffer *buf;

	struct pt *pt = this_cpu_ptr(&pt_ctx);

	struct pt *pt = this_cpu_ptr(&pt_ctx);

	struct hw_perf_event *hwc = &event->hw;

	struct hw_perf_event *hwc = &event->hw;

	int ret = -EBUSY;

	int ret = -EBUSY;
@@ -1067,34 +1052,18 @@ static int pt_event_add(struct perf_event *event, int mode) 
	if (pt->handle.event)

	if (pt->handle.event)

		goto fail;

		goto fail;





	buf = perf_aux_output_begin(&pt->handle, event);

	ret = -EINVAL;

	if (!buf)

		goto fail_stop;



	pt_buffer_reset_offsets(buf, pt->handle.head);

	if (!buf->snapshot) {

		ret = pt_buffer_reset_markers(buf, &pt->handle);

		if (ret)

			goto fail_end_stop;

	}



	if (mode & PERF_EF_START) {

	if (mode & PERF_EF_START) {

		pt_event_start(event, 0);

		pt_event_start(event, 0);

		ret = -EBUSY;

		ret = -EINVAL;

		if (hwc->state == PERF_HES_STOPPED)

		if (hwc->state == PERF_HES_STOPPED)

			goto fail_end_stop;

			goto fail;

	} else {

	} else {

		hwc->state = PERF_HES_STOPPED;

		hwc->state = PERF_HES_STOPPED;

	}

	}





	return 0;

	ret = 0;



fail_end_stop:

	perf_aux_output_end(&pt->handle, 0, true);

fail_stop:

	hwc->state = PERF_HES_STOPPED;

fail:

fail:



	return ret;

	return ret;

}

}