Messages in this thread Patch in this message | | | From | Phil Auld <> | Subject | [PATCH] sched/rt: silence double clock update warning by using rq_lock wrappers | Date | Thu, 15 Aug 2019 10:53:54 -0400 |
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With WARN_DOUBLE_CLOCK enabled a false positive warning can occur in rt
[] rq->clock_update_flags & RQCF_UPDATED [] WARNING: CPU: 6 PID: 21426 at kernel/sched/core.c:225 update_rq_clock+0x90/0x130 [] Call Trace: [] update_rq_clock+0x90/0x130 [] sched_rt_period_timer+0x11f/0x340 [] __hrtimer_run_queues+0x100/0x280 [] hrtimer_interrupt+0x100/0x220 [] smp_apic_timer_interrupt+0x6a/0x130 [] apic_timer_interrupt+0xf/0x20
sched_rt_period_timer does: raw_spin_lock(&rq->lock); update_rq_clock(rq);
which triggers the warning because of not using the rq_lock wrappers. So, use the wrappers.
Signed-off-by: Phil Auld <pauld@redhat.com> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Valentin Schneider <valentin.schneider@arm.com> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> --- kernel/sched/rt.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index a532558a5176..0846e71114ee 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -831,6 +831,7 @@ static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun) int enqueue = 0; struct rt_rq *rt_rq = sched_rt_period_rt_rq(rt_b, i); struct rq *rq = rq_of_rt_rq(rt_rq); + struct rq_flags rf; int skip; /* @@ -845,7 +846,7 @@ static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun) if (skip) continue; - raw_spin_lock(&rq->lock); + rq_lock(rq, &rf); update_rq_clock(rq); if (rt_rq->rt_time) { @@ -883,7 +884,7 @@ static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun) if (enqueue) sched_rt_rq_enqueue(rt_rq); - raw_spin_unlock(&rq->lock); + rq_unlock(rq, &rf); } if (!throttled && (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF)) -- 2.18.0
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