Commit caf8b765 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

perf/core: Simplify perf_init_event() 



Use the <linux/cleanup.h> guard() and scoped_guard() infrastructure
to simplify the control flow.

Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Reviewed-by: default avatarRavi Bangoria <ravi.bangoria@amd.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20241104135518.302444446@infradead.org
parent 6c8b0b83

kernel/events/core.c

+12 −19
Original line number Diff line number Diff line
@@ -12101,10 +12101,10 @@ static int perf_try_init_event(struct pmu *pmu, struct perf_event *event) 
static struct pmu *perf_init_event(struct perf_event *event)

{

	bool extended_type = false;

	int idx, type, ret;

	struct pmu *pmu;

	int type, ret;



	idx = srcu_read_lock(&pmus_srcu);

	guard(srcu)(&pmus_srcu);



	/*

	 * Save original type before calling pmu->event_init() since certain
@@ -12117,7 +12117,7 @@ static struct pmu *perf_init_event(struct perf_event *event) 
		pmu = event->parent->pmu;

		ret = perf_try_init_event(pmu, event);

		if (!ret)

			goto unlock;

			return pmu;

	}



	/*
@@ -12136,13 +12136,12 @@ static struct pmu *perf_init_event(struct perf_event *event) 
	}



again:

	rcu_read_lock();

	scoped_guard (rcu)

		pmu = idr_find(&pmu_idr, type);

	rcu_read_unlock();

	if (pmu) {

		if (event->attr.type != type && type != PERF_TYPE_RAW &&

		    !(pmu->capabilities & PERF_PMU_CAP_EXTENDED_HW_TYPE))

			goto fail;

			return ERR_PTR(-ENOENT);



		ret = perf_try_init_event(pmu, event);

		if (ret == -ENOENT && event->attr.type != type && !extended_type) {
@@ -12151,27 +12150,21 @@ static struct pmu *perf_init_event(struct perf_event *event) 
		}



		if (ret)

			pmu = ERR_PTR(ret);

			return ERR_PTR(ret);



		goto unlock;

		return pmu;

	}



	list_for_each_entry_rcu(pmu, &pmus, entry, lockdep_is_held(&pmus_srcu)) {

		ret = perf_try_init_event(pmu, event);

		if (!ret)

			goto unlock;

			return pmu;



		if (ret != -ENOENT) {

			pmu = ERR_PTR(ret);

			goto unlock;

		}

		if (ret != -ENOENT)

			return ERR_PTR(ret);

	}

fail:

	pmu = ERR_PTR(-ENOENT);

unlock:

	srcu_read_unlock(&pmus_srcu, idx);



	return pmu;

	return ERR_PTR(-ENOENT);

}



static void attach_sb_event(struct perf_event *event)