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| author | Peter Zijlstra <peterz@infradead.org> | 2023-04-03 11:08:58 +0200 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2023-04-05 09:58:46 +0200 |
| commit | b168098912926236bbeebaf7795eb7aab76d2b45 (patch) | |
| tree | 325d00ea96f4c6f67e86712514e4b277521475e2 /fs | |
| parent | 197b6b60ae7bc51dd0814953c562833143b292aa (diff) | |
perf: Optimize perf_pmu_migrate_context()
Thomas reported that offlining CPUs spends a lot of time in
synchronize_rcu() as called from perf_pmu_migrate_context() even though
he's not actually using uncore events.
Turns out, the thing is unconditionally waiting for RCU, even if there's
no actual events to migrate.
Fixes: 0cda4c023132 ("perf: Introduce perf_pmu_migrate_context()")
Reported-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Link: https://lkml.kernel.org/r/20230403090858.GT4253@hirez.programming.kicks-ass.net
Diffstat (limited to 'fs')
0 files changed, 0 insertions, 0 deletions