From: Peter Zijlstra <pet...@infradead.org> Enable perf_event_read() to update entire groups at once, this will be useful for read transactions.
Cc: Ingo Molnar <mi...@redhat.com> Cc: Arnaldo Carvalho de Melo <a...@kernel.org> Cc: Michael Ellerman <m...@ellerman.id.au> Cc: Sukadev Bhattiprolu <suka...@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org> Link: http://lkml.kernel.org/r/20150723080435.ge25...@twins.programming.kicks-ass.net --- kernel/events/core.c | 39 ++++++++++++++++++++++++++++++++------- 1 file changed, 32 insertions(+), 7 deletions(-) diff --git a/kernel/events/core.c b/kernel/events/core.c index be39e63..7bb9141 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -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); } -- 1.7.9.5 _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
