Jens, Is there any reason the following patch from Shaohua didn't go in? We are hitting this WARN_ON during hotplug testing, and this patch fixes the problem. The previous posting is located here:
http://linux-kernel.2935.n7.nabble.com/patch-blk-mq-suppress-a-warning-td895340.html Cheers, Jeff From: Shaohua Li <s...@kernel.org> The warning is hit when cpu hotplug is running. After scheduler puts a cpu online and before blk-mq mapping reinit, a task can queue a request and run the queue. At that time the cpu isn't in hctx->cpumask, but the cpu is mapped into hctx 0. When the race happens, hctx->cpumask doesn't set the cpu and ctx->index_hw/hctx->nr_ctx isn't correct, but it doesn't cause any problem. So just suppress the warning here. Signed-off-by: Shaohua Li <s...@kernel.org> Signed-off-by: Jeff Moyer <jmo...@redhat.com> diff --git a/block/blk-mq.c b/block/blk-mq.c index da1ab56..491beb7 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -702,7 +702,7 @@ static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx) struct list_head *dptr; int queued; - WARN_ON(!cpumask_test_cpu(raw_smp_processor_id(), hctx->cpumask)); + WARN_ON(q->mq_ops->map_queue(q, raw_smp_processor_id()) != hctx); if (unlikely(test_bit(BLK_MQ_S_STOPPED, &hctx->state))) return; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
