From 8ea8311b75a40bdea03e7f8228a0578b6367e9d1 Mon Sep 17 00:00:00 2001 From: Clark Williams Date: Mon, 20 Nov 2017 14:26:12 -0600 Subject: [PATCH] [rt] sched/rt: fix panic in double_lock_balance with simplified IPI RT balancing I was testing 4.14-rt1 on a large system (cores == 96) and saw that we were getting into an rt balancing storm, so I tried applying Steven's patch (not upstream yet): sched/rt: Simplify the IPI rt balancing logic Booting the resulting kernel yielded a panic in double_lock_balance() due to irqs not being disabled. This patch changes the calls to raw_spin_{lock,unlock} in the function rto_push_irq_work_function, to be raw_spin_{lock,unlock}_irq. Not sure if that's too heavy a hammer, but the resulting kernel boots and runs and survives 12h runs of rteval. Once Steven's patch goes in upstream, we'll need something like this in RT. Signed-off-by: Clark Williams --- kernel/sched/rt.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index 57fb251dd8ce..a5cd0cea2f0f 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -2008,9 +2008,9 @@ void rto_push_irq_work_func(struct irq_work *work) * When it gets updated, a check is made if a push is possible. */ if (has_pushable_tasks(rq)) { - raw_spin_lock(&rq->lock); + raw_spin_lock_irq(&rq->lock); push_rt_tasks(rq); - raw_spin_unlock(&rq->lock); + raw_spin_unlock_irq(&rq->lock); } raw_spin_lock(&rq->rd->rto_lock); -- 2.14.3 -- The United States Coast Guard Ruining Natural Selection since 1790