diff options
Diffstat (limited to 'block')
| -rw-r--r-- | block/blk-mq.c | 14 | ||||
| -rw-r--r-- | block/blk-softirq.c | 5 |
2 files changed, 16 insertions, 3 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c index 1dc157c85a83..89bd9cb9defc 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -568,6 +568,20 @@ static void __blk_mq_complete_request(struct request *rq) if (!blk_mq_mark_complete(rq)) return; + /* + * Most of single queue controllers, there is only one irq vector + * for handling IO completion, and the only irq's affinity is set + * as all possible CPUs. On most of ARCHs, this affinity means the + * irq is handled on one specific CPU. + * + * So complete IO reqeust in softirq context in case of single queue + * for not degrading IO performance by irqsoff latency. + */ + if (rq->q->nr_hw_queues == 1) { + __blk_complete_request(rq); + return; + } + if (!test_bit(QUEUE_FLAG_SAME_COMP, &rq->q->queue_flags)) { rq->q->softirq_done_fn(rq); return; diff --git a/block/blk-softirq.c b/block/blk-softirq.c index 15c1f5e12eb8..e47a2f751884 100644 --- a/block/blk-softirq.c +++ b/block/blk-softirq.c @@ -97,8 +97,8 @@ static int blk_softirq_cpu_dead(unsigned int cpu) void __blk_complete_request(struct request *req) { - int ccpu, cpu; struct request_queue *q = req->q; + int cpu, ccpu = q->mq_ops ? req->mq_ctx->cpu : req->cpu; unsigned long flags; bool shared = false; @@ -110,8 +110,7 @@ void __blk_complete_request(struct request *req) /* * Select completion CPU */ - if (req->cpu != -1) { - ccpu = req->cpu; + if (test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags) && ccpu != -1) { if (!test_bit(QUEUE_FLAG_SAME_FORCE, &q->queue_flags)) shared = cpus_share_cache(cpu, ccpu); } else |