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perf/x86/intel/bts: Move transaction start/stop to start/stop callbacks

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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>
This commit is contained in:
Alexander Shishkin 2016-03-04 15:42:49 +02:00 • committed by Ingo Molnar
parent 66d219014a
commit 981a4cb380
1 changed files with 48 additions and 57 deletions
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105
arch/x86/events/intel/bts.c
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@ -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); 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) static void bts_update(struct bts_ctx *bts)
{ {
int cpu = raw_smp_processor_id(); 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) static void __bts_event_start(struct perf_event *event)
{ {
struct bts_ctx *bts = this_cpu_ptr(&bts_ctx); struct bts_ctx *bts = this_cpu_ptr(&bts_ctx);
struct bts_buffer *buf = perf_get_aux(&bts->handle); struct bts_buffer *buf = perf_get_aux(&bts->handle);
u64 config = 0; u64 config = 0;
if (!buf || bts_buffer_is_full(buf, bts))
return;
event->hw.itrace_started = 1;
event->hw.state = 0;
if (!buf->snapshot) if (!buf->snapshot)
config |= ARCH_PERFMON_EVENTSEL_INT; config |= ARCH_PERFMON_EVENTSEL_INT;
if (!event->attr.exclude_kernel) if (!event->attr.exclude_kernel)
@ -241,16 +226,41 @@ static void __bts_event_start(struct perf_event *event)
wmb(); wmb();
intel_pmu_enable_bts(config); intel_pmu_enable_bts(config);
} }
static void bts_event_start(struct perf_event *event, int flags) 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_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); __bts_event_start(event);
/* PMI handler: this counter is running and likely generating PMIs */ /* PMI handler: this counter is running and likely generating PMIs */
ACCESS_ONCE(bts->started) = 1; 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) 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) 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_ctx *bts = this_cpu_ptr(&bts_ctx);
struct bts_buffer *buf = perf_get_aux(&bts->handle);
/* PMI handler: don't restart this counter */ /* PMI handler: don't restart this counter */
ACCESS_ONCE(bts->started) = 0; ACCESS_ONCE(bts->started) = 0;
__bts_event_stop(event); __bts_event_stop(event);
if (flags & PERF_EF_UPDATE) if (flags & PERF_EF_UPDATE) {
bts_update(bts); 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) 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) 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); 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) 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 bts_ctx *bts = this_cpu_ptr(&bts_ctx);
struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
struct hw_perf_event *hwc = &event->hw; struct hw_perf_event *hwc = &event->hw;
int ret = -EBUSY;
event->hw.state = PERF_HES_STOPPED; 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) if (bts->handle.event)
return -EBUSY; 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) { if (mode & PERF_EF_START) {
bts_event_start(event, 0); bts_event_start(event, 0);
if (hwc->state & PERF_HES_STOPPED) { if (hwc->state & PERF_HES_STOPPED)
bts_event_del(event, 0); return -EINVAL;
return -EBUSY;
}
} }
return 0; return 0;