The following commit has been merged into the perf/core branch of tip: Commit-ID: caf8b765d453198d4ca5305d9e207535934b6e3b Gitweb: https://git.kernel.org/tip/caf8b765d453198d4ca5305d9e207535934b6e3b Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx> AuthorDate: Mon, 04 Nov 2024 14:39:16 +01:00 Committer: Ingo Molnar <mingo@xxxxxxxxxx> CommitterDate: Tue, 04 Mar 2025 09:42:32 +01:00 perf/core: Simplify perf_init_event() Use the <linux/cleanup.h> guard() and scoped_guard() infrastructure to simplify the control flow. Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> Reviewed-by: Ravi Bangoria <ravi.bangoria@xxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20241104135518.302444446@xxxxxxxxxxxxx --- kernel/events/core.c | 31 ++++++++++++------------------- 1 file changed, 12 insertions(+), 19 deletions(-) diff --git a/kernel/events/core.c b/kernel/events/core.c index 215dad5..fd35236 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -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(); - pmu = idr_find(&pmu_idr, type); - rcu_read_unlock(); + scoped_guard (rcu) + pmu = idr_find(&pmu_idr, type); 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 @@ again: } 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)
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