From: Sebastian Andrzej Siewior Date: Tue, 14 Jul 2015 14:26:34 +0200 Subject: block/mq: do not invoke preempt_disable() Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.18/older/patches-4.18.5-rt3.tar.xz preempt_disable() and get_cpu() don't play well together with the sleeping locks it tries to allocate later. It seems to be enough to replace it with get_cpu_light() and migrate_disable(). Signed-off-by: Sebastian Andrzej Siewior --- block/blk-mq.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -568,7 +568,7 @@ static void __blk_mq_complete_request(st return; } - cpu = get_cpu(); + cpu = get_cpu_light(); if (!test_bit(QUEUE_FLAG_SAME_FORCE, &rq->q->queue_flags)) shared = cpus_share_cache(cpu, ctx->cpu); @@ -580,7 +580,7 @@ static void __blk_mq_complete_request(st } else { rq->q->softirq_done_fn(rq); } - put_cpu(); + put_cpu_light(); } static void hctx_unlock(struct blk_mq_hw_ctx *hctx, int srcu_idx) @@ -1324,14 +1324,14 @@ static void __blk_mq_delay_run_hw_queue( return; if (!async && !(hctx->flags & BLK_MQ_F_BLOCKING)) { - int cpu = get_cpu(); + int cpu = get_cpu_light(); if (cpumask_test_cpu(cpu, hctx->cpumask)) { __blk_mq_run_hw_queue(hctx); - put_cpu(); + put_cpu_light(); return; } - put_cpu(); + put_cpu_light(); } kblockd_mod_delayed_work_on(blk_mq_hctx_next_cpu(hctx), &hctx->run_work,