Re: [tip: perf/core] perf: Make perf_pmu_unregister() useable

From: Peter Zijlstra
Date: Thu Apr 17 2025 - 04:08:28 EST


Subject: perf: Fix event timekeeping merge
From: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Date: Wed Apr 16 11:36:24 CEST 2025

Due to an oversight in merging da916e96e2de ("perf: Make
perf_pmu_unregister() useable") on top of a3c3c66670ce ("perf/core:
Fix child_total_time_enabled accounting bug at task exit") the
timekeeping fix from this latter patch got undone.

Fixes: da916e96e2de ("perf: Make perf_pmu_unregister() useable")
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
---
kernel/events/core.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -2500,14 +2500,14 @@ __perf_remove_from_context(struct perf_e
state = PERF_EVENT_STATE_DEAD;
}
event_sched_out(event, ctx);
+ perf_event_set_state(event, min(event->state, state));
+
if (flags & DETACH_GROUP)
perf_group_detach(event);
if (flags & DETACH_CHILD)
perf_child_detach(event);
list_del_event(event, ctx);

- event->state = min(event->state, state);
-
if (!pmu_ctx->nr_events) {
pmu_ctx->rotate_necessary = 0;