Commit 2714c396 authored Oct 29, 2020 by Peter Zijlstra

perf: Fix event multiplexing for exclusive groups



Commit 9e630205 ("perf: Use hrtimers for event multiplexing")
placed the hrtimer (re)start call in the wrong place.  Instead of
capturing all scheduling failures, it only considered the PMU failure.

The result is that groups using perf_event_attr::exclusive are no
longer rotated.

Fixes: 9e630205 ("perf: Use hrtimers for event multiplexing")
Reported-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201029162902.038667689@infradead.org

parent 251ff2d4

kernel/events/core.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -2612,7 +2612,6 @@ group_error:

		error:
		pmu->cancel_txn(pmu);
		perf_mux_hrtimer_restart(cpuctx);
		return -EAGAIN;
		}

		@@ -3672,6 +3671,7 @@ static int merge_sched_in(struct perf_event event, void data)

		*can_add_hw = 0;
		ctx->rotate_necessary = 1;
		perf_mux_hrtimer_restart(cpuctx);
		}

		return 0;

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