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perf/core: Add group reads to perf_event_read() 

Enable perf_event_read() to update entire groups at once, this will be
useful for read transactions.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/20150723080435.GE25159@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Peter Zijlstra 2015-09-03 20:07:48 -07:00 committed by Ingo Molnar
parent b15f495b4e
commit 0492d4c5b8
1 changed files with 32 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

39
kernel/events/core.c
View File

@ -3184,12 +3184,18 @@ void perf_event_exec(void)
rcu_read_unlock();
}
struct perf_read_data {
struct perf_event *event;
bool group;
};
/*
* Cross CPU call to read the hardware event
*/
static void __perf_event_read(void *info)
{
struct perf_event *event = info;
struct perf_read_data *data = info;
struct perf_event *sub, *event = data->event;
struct perf_event_context *ctx = event->ctx;
struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
@ -3208,9 +3214,21 @@ static void __perf_event_read(void *info)
update_context_time(ctx);
update_cgrp_time_from_event(event);
}
update_event_times(event);
if (event->state == PERF_EVENT_STATE_ACTIVE)
event->pmu->read(event);
if (!data->group)
goto unlock;
list_for_each_entry(sub, &event->sibling_list, group_entry) {
update_event_times(sub);
if (sub->state == PERF_EVENT_STATE_ACTIVE)
sub->pmu->read(sub);
}
unlock:
raw_spin_unlock(&ctx->lock);
}
@ -3275,15 +3293,19 @@ u64 perf_event_read_local(struct perf_event *event)
return val;
}
static void perf_event_read(struct perf_event *event)
static void perf_event_read(struct perf_event *event, bool group)
{
/*
* If event is enabled and currently active on a CPU, update the
* value in the event structure:
*/
if (event->state == PERF_EVENT_STATE_ACTIVE) {
struct perf_read_data data = {
.event = event,
.group = group,
};
smp_call_function_single(event->oncpu,
__perf_event_read, event, 1);
__perf_event_read, &data, 1);
} else if (event->state == PERF_EVENT_STATE_INACTIVE) {
struct perf_event_context *ctx = event->ctx;
unsigned long flags;
@ -3298,7 +3320,10 @@ static void perf_event_read(struct perf_event *event)
update_context_time(ctx);
update_cgrp_time_from_event(event);
}
update_event_times(event);
if (group)
update_group_times(event);
else
update_event_times(event);
raw_spin_unlock_irqrestore(&ctx->lock, flags);
}
}
@ -3817,7 +3842,7 @@ u64 perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running)
mutex_lock(&event->child_mutex);
perf_event_read(event);
perf_event_read(event, false);
total += perf_event_count(event);
*enabled += event->total_time_enabled +
@ -3826,7 +3851,7 @@ u64 perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running)
atomic64_read(&event->child_total_time_running);
list_for_each_entry(child, &event->child_list, child_list) {
perf_event_read(child);
perf_event_read(child, false);
total += perf_event_count(child);
*enabled += child->total_time_enabled;
*running += child->total_time_running;
@ -3987,7 +4012,7 @@ static unsigned int perf_poll(struct file *file, poll_table *wait)
static void _perf_event_reset(struct perf_event *event)
{
perf_event_read(event);
perf_event_read(event, false);
local64_set(&event->count, 0);
perf_event_update_userpage(event);
}