Commit 7e5b2a01 authored Aug 11, 2011 by Mark Rutland Committed by Ingo Molnar Aug 14, 2011

perf: provide PMU when initing events



Currently, an event's 'pmu' field is set after pmu::event_init() is
called. This means that pmu::event_init() must figure out which struct
pmu the event was initialised from. This makes it difficult to
consolidate common event initialisation code for similar PMUs, and
very difficult to implement drivers for PMUs which can have multiple
instances (e.g. a USB controller PMU, a GPU PMU, etc).

This patch sets the 'pmu' field before initialising the event, allowing
event init code to identify the struct pmu instance easily. In the
event of failure to initialise an event, the event is destroyed via
kfree() without calling perf_event::destroy(), so this shouldn't
result in bad behaviour even if the destroy field was set before
failure to initialise was noted.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1313062280-19123-1-git-send-email-mark.rutland@arm.com


Signed-off-by: Ingo Molnar <mingo@elte.hu>

parent 144060fe

kernel/events/core.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -5716,6 +5716,7 @@ struct pmu perf_init_event(struct perf_event event)
		pmu = idr_find(&pmu_idr, event->attr.type);
		rcu_read_unlock();
		if (pmu) {
		event->pmu = pmu;
		ret = pmu->event_init(event);
		if (ret)
		pmu = ERR_PTR(ret);
		@@ -5723,6 +5724,7 @@ struct pmu perf_init_event(struct perf_event event)
		}

		list_for_each_entry_rcu(pmu, &pmus, entry) {
		event->pmu = pmu;
		ret = pmu->event_init(event);
		if (!ret)
		goto unlock;
		@@ -5849,8 +5851,6 @@ done:
		return ERR_PTR(err);
		}

		event->pmu = pmu;

		if (!event->parent) {
		if (event->attach_state & PERF_ATTACH_TASK)
		jump_label_inc(&perf_sched_events);

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