Messages in this thread | | | Date | Fri, 29 Nov 2019 11:31:19 +0100 | From | Sebastian Andrzej Siewior <> | Subject | Re: [PATCH] perf/core: Add SRCU annotation for pmus list walk |
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On 2019-11-19 13:14:29 [+0100], To linux-kernel@vger.kernel.org wrote: > Since commit > 28875945ba98d ("rcu: Add support for consolidated-RCU reader checking") > > there is an additional check to ensure that a RCU related lock is held > while the RCU list is iterated. > This section holds the SRCU reader lock instead. > > Add annotation to list_for_each_entry_rcu() that pmus_srcu must be > acquired during the list traversal. > > Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> > --- > > I see the warning in in v5.4-rc during boot. For some reason I don't see > it in tip/master during boot but "perf stat w" triggers it again (among > other things).
ping.
> kernel/events/core.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/events/core.c b/kernel/events/core.c > index 5224388872069..dbb3b26a55612 100644 > --- a/kernel/events/core.c > +++ b/kernel/events/core.c > @@ -10497,7 +10497,7 @@ static struct pmu *perf_init_event(struct perf_event *event) > goto unlock; > } > > - list_for_each_entry_rcu(pmu, &pmus, entry) { > + list_for_each_entry_rcu(pmu, &pmus, entry, lockdep_is_held(&pmus_srcu)) { > ret = perf_try_init_event(pmu, event); > if (!ret) > goto unlock;
Sebastian
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