From: Ming Lei <ming.lei@redhat.com>
To: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org, Minwoo Im <minwoo.im.dev@gmail.com>,
Ming Lei <ming.lei@redhat.com>,
Bart Van Assche <bvanassche@acm.org>,
Hannes Reinecke <hare@suse.com>, Christoph Hellwig <hch@lst.de>,
Thomas Gleixner <tglx@linutronix.de>,
Keith Busch <keith.busch@intel.com>
Subject: [PATCH V2 5/5] blk-mq: handle requests dispatched from IO scheduler in case that hctx is dead
Date: Mon, 12 Aug 2019 21:43:12 +0800 [thread overview]
Message-ID: <20190812134312.16732-6-ming.lei@redhat.com> (raw)
In-Reply-To: <20190812134312.16732-1-ming.lei@redhat.com>
If hctx becomes dead, all in-queue IO requests aimed at this hctx have to
be re-submitted, so cover requests queued in scheduler queue.
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Keith Busch <keith.busch@intel.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
block/blk-mq.c | 30 +++++++++++++++++++++++++-----
1 file changed, 25 insertions(+), 5 deletions(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index ed334fd867c4..a722ce53fb39 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2294,6 +2294,7 @@ static int blk_mq_hctx_notify_dead(unsigned int cpu, struct hlist_node *node)
enum hctx_type type;
bool hctx_dead;
struct request *rq;
+ struct elevator_queue *e;
hctx = hlist_entry_safe(node, struct blk_mq_hw_ctx, cpuhp_dead);
ctx = __blk_mq_get_ctx(hctx->queue, cpu);
@@ -2304,12 +2305,31 @@ static int blk_mq_hctx_notify_dead(unsigned int cpu, struct hlist_node *node)
hctx_dead = cpumask_first_and(hctx->cpumask, cpu_online_mask) >=
nr_cpu_ids;
- spin_lock(&ctx->lock);
- if (!list_empty(&ctx->rq_lists[type])) {
- list_splice_init(&ctx->rq_lists[type], &tmp);
- blk_mq_hctx_clear_pending(hctx, ctx);
+ e = hctx->queue->elevator;
+ if (!e) {
+ spin_lock(&ctx->lock);
+ if (!list_empty(&ctx->rq_lists[type])) {
+ list_splice_init(&ctx->rq_lists[type], &tmp);
+ blk_mq_hctx_clear_pending(hctx, ctx);
+ }
+ spin_unlock(&ctx->lock);
+ } else if (hctx_dead) {
+ LIST_HEAD(sched_tmp);
+
+ while ((rq = e->type->ops.dispatch_request(hctx))) {
+ if (rq->mq_hctx != hctx)
+ list_add(&rq->queuelist, &sched_tmp);
+ else
+ list_add(&rq->queuelist, &tmp);
+ }
+
+ while (!list_empty(&sched_tmp)) {
+ rq = list_entry(sched_tmp.next, struct request,
+ queuelist);
+ list_del_init(&rq->queuelist);
+ blk_mq_sched_insert_request(rq, true, true, true);
+ }
}
- spin_unlock(&ctx->lock);
if (list_empty(&tmp))
return 0;
--
2.20.1
next prev parent reply other threads:[~2019-08-12 13:43 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-12 13:43 [PATCH V2 0/5] blk-mq: improvement on handling IO during CPU hotplug Ming Lei
2019-08-12 13:43 ` [PATCH V2 1/5] blk-mq: add new state of BLK_MQ_S_INTERNAL_STOPPED Ming Lei
2019-08-12 13:43 ` [PATCH V2 2/5] blk-mq: add blk-mq flag of BLK_MQ_F_NO_MANAGED_IRQ Ming Lei
2019-08-12 13:43 ` [PATCH V2 3/5] blk-mq: stop to handle IO before hctx's all CPUs become offline Ming Lei
2019-08-12 14:24 ` Hannes Reinecke
2019-08-12 22:24 ` Ming Lei
2019-08-12 13:43 ` [PATCH V2 4/5] blk-mq: re-submit IO in case that hctx is dead Ming Lei
2019-08-12 14:26 ` Hannes Reinecke
2019-08-12 22:30 ` Ming Lei
2019-08-12 13:43 ` Ming Lei [this message]
2019-08-12 13:46 ` [PATCH V2 0/5] blk-mq: improvement on handling IO during CPU hotplug Ming Lei
2019-08-12 16:21 ` John Garry
2019-08-12 22:45 ` Ming Lei
2019-08-22 17:39 ` John Garry
2019-10-02 9:56 ` John Garry
2019-10-02 14:36 ` Jens Axboe
2019-10-06 2:47 ` Ming Lei
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