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)
|