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authorAlexander Shishkin <alexander.shishkin@linux.intel.com>2016-03-04 15:42:49 +0200
committerIngo Molnar <mingo@kernel.org>2016-03-31 10:30:44 +0200
commit981a4cb380d3dff7010ce9f89618064a254eab8c (patch)
tree3f051a274bdb56b3cc11e234d34c3ea54f3b8707
parent66d219014a4ee47ad4ca2b9db5fe6547353e2a56 (diff)
perf/x86/intel/bts: Move transaction start/stop to 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 bts_event_{add,del} to bts_event_{start,stop}. As a bonus, we get rid of bts_buffer_is_full(), which is already taken care of by perf_aux_output_begin() anyway. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter 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/1457098969-21595-6-git-send-email-alexander.shishkin@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
-rw-r--r--arch/x86/events/intel/bts.c105
1 files changed, 48 insertions, 57 deletions
diff --git a/arch/x86/events/intel/bts.c b/arch/x86/events/intel/bts.c
index b99dc9258c0f..0a6e393a2e62 100644
--- a/arch/x86/events/intel/bts.c
+++ b/arch/x86/events/intel/bts.c
@@ -171,18 +171,6 @@ static void bts_buffer_pad_out(struct bts_phys *phys, unsigned long head)
memset(page_address(phys->page) + index, 0, phys->size - index);
}
-static bool bts_buffer_is_full(struct bts_buffer *buf, struct bts_ctx *bts)
-{
- if (buf->snapshot)
- return false;
-
- if (local_read(&buf->data_size) >= bts->handle.size ||
- bts->handle.size - local_read(&buf->data_size) < BTS_RECORD_SIZE)
- return true;
-
- return false;
-}
-
static void bts_update(struct bts_ctx *bts)
{
int cpu = raw_smp_processor_id();
@@ -213,18 +201,15 @@ static void bts_update(struct bts_ctx *bts)
}
}
+static int
+bts_buffer_reset(struct bts_buffer *buf, struct perf_output_handle *handle);
+
static void __bts_event_start(struct perf_event *event)
{
struct bts_ctx *bts = this_cpu_ptr(&bts_ctx);
struct bts_buffer *buf = perf_get_aux(&bts->handle);
u64 config = 0;
- if (!buf || bts_buffer_is_full(buf, bts))
- return;
-
- event->hw.itrace_started = 1;
- event->hw.state = 0;
-
if (!buf->snapshot)
config |= ARCH_PERFMON_EVENTSEL_INT;
if (!event->attr.exclude_kernel)
@@ -241,16 +226,41 @@ static void __bts_event_start(struct perf_event *event)
wmb();
intel_pmu_enable_bts(config);
+
}
static void bts_event_start(struct perf_event *event, int flags)
{
+ struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
struct bts_ctx *bts = this_cpu_ptr(&bts_ctx);
+ struct bts_buffer *buf;
+
+ buf = perf_aux_output_begin(&bts->handle, event);
+ if (!buf)
+ goto fail_stop;
+
+ if (bts_buffer_reset(buf, &bts->handle))
+ goto fail_end_stop;
+
+ bts->ds_back.bts_buffer_base = cpuc->ds->bts_buffer_base;
+ bts->ds_back.bts_absolute_maximum = cpuc->ds->bts_absolute_maximum;
+ bts->ds_back.bts_interrupt_threshold = cpuc->ds->bts_interrupt_threshold;
+
+ event->hw.itrace_started = 1;
+ event->hw.state = 0;
__bts_event_start(event);
/* PMI handler: this counter is running and likely generating PMIs */
ACCESS_ONCE(bts->started) = 1;
+
+ return;
+
+fail_end_stop:
+ perf_aux_output_end(&bts->handle, 0, false);
+
+fail_stop:
+ event->hw.state = PERF_HES_STOPPED;
}
static void __bts_event_stop(struct perf_event *event)
@@ -269,15 +279,32 @@ static void __bts_event_stop(struct perf_event *event)
static void bts_event_stop(struct perf_event *event, int flags)
{
+ struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
struct bts_ctx *bts = this_cpu_ptr(&bts_ctx);
+ struct bts_buffer *buf = perf_get_aux(&bts->handle);
/* PMI handler: don't restart this counter */
ACCESS_ONCE(bts->started) = 0;
__bts_event_stop(event);
- if (flags & PERF_EF_UPDATE)
+ if (flags & PERF_EF_UPDATE) {
bts_update(bts);
+
+ if (buf) {
+ if (buf->snapshot)
+ bts->handle.head =
+ local_xchg(&buf->data_size,
+ buf->nr_pages << PAGE_SHIFT);
+ perf_aux_output_end(&bts->handle, local_xchg(&buf->data_size, 0),
+ !!local_xchg(&buf->lost, 0));
+ }
+
+ cpuc->ds->bts_index = bts->ds_back.bts_buffer_base;
+ cpuc->ds->bts_buffer_base = bts->ds_back.bts_buffer_base;
+ cpuc->ds->bts_absolute_maximum = bts->ds_back.bts_absolute_maximum;
+ cpuc->ds->bts_interrupt_threshold = bts->ds_back.bts_interrupt_threshold;
+ }
}
void intel_bts_enable_local(void)
@@ -417,34 +444,14 @@ int intel_bts_interrupt(void)
static void bts_event_del(struct perf_event *event, int mode)
{
- struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
- struct bts_ctx *bts = this_cpu_ptr(&bts_ctx);
- struct bts_buffer *buf = perf_get_aux(&bts->handle);
-
bts_event_stop(event, PERF_EF_UPDATE);
-
- if (buf) {
- if (buf->snapshot)
- bts->handle.head =
- local_xchg(&buf->data_size,
- buf->nr_pages << PAGE_SHIFT);
- perf_aux_output_end(&bts->handle, local_xchg(&buf->data_size, 0),
- !!local_xchg(&buf->lost, 0));
- }
-
- cpuc->ds->bts_index = bts->ds_back.bts_buffer_base;
- cpuc->ds->bts_buffer_base = bts->ds_back.bts_buffer_base;
- cpuc->ds->bts_absolute_maximum = bts->ds_back.bts_absolute_maximum;
- cpuc->ds->bts_interrupt_threshold = bts->ds_back.bts_interrupt_threshold;
}
static int bts_event_add(struct perf_event *event, int mode)
{
- struct bts_buffer *buf;
struct bts_ctx *bts = this_cpu_ptr(&bts_ctx);
struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
struct hw_perf_event *hwc = &event->hw;
- int ret = -EBUSY;
event->hw.state = PERF_HES_STOPPED;
@@ -454,26 +461,10 @@ static int bts_event_add(struct perf_event *event, int mode)
if (bts->handle.event)
return -EBUSY;
- buf = perf_aux_output_begin(&bts->handle, event);
- if (!buf)
- return -EINVAL;
-
- ret = bts_buffer_reset(buf, &bts->handle);
- if (ret) {
- perf_aux_output_end(&bts->handle, 0, false);
- return ret;
- }
-
- bts->ds_back.bts_buffer_base = cpuc->ds->bts_buffer_base;
- bts->ds_back.bts_absolute_maximum = cpuc->ds->bts_absolute_maximum;
- bts->ds_back.bts_interrupt_threshold = cpuc->ds->bts_interrupt_threshold;
-
if (mode & PERF_EF_START) {
bts_event_start(event, 0);
- if (hwc->state & PERF_HES_STOPPED) {
- bts_event_del(event, 0);
- return -EBUSY;
- }
+ if (hwc->state & PERF_HES_STOPPED)
+ return -EINVAL;
}
return 0;