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blk-mq: Always complete remote completions requests in softirq 

Controllers with multiple queues have their IRQ-handelers pinned to a
CPU. The core shouldn't need to complete the request on a remote CPU.

Remove this case and always raise the softirq to complete the request.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
master
Sebastian Andrzej Siewior 2021-01-23 21:10:26 +01:00 committed by Jens Axboe
parent 93e4f73a93
commit 0a2efafbb1
1 changed files with 1 additions and 13 deletions
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14
block/blk-mq.c
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@ -628,19 +628,7 @@ static void __blk_mq_complete_request_remote(void *data)
{
struct request *rq = data;
/*
* For most of single queue controllers, there is only one irq vector
* for handling I/O completion, and the only irq's affinity is set
* to all possible CPUs. On most of ARCHs, this affinity means the irq
* is handled on one specific CPU.
*
* So complete I/O requests in softirq context in case of single queue
* devices to avoid degrading I/O performance due to irqsoff latency.
*/
if (rq->q->nr_hw_queues == 1)
blk_mq_trigger_softirq(rq);
else
rq->q->mq_ops->complete(rq);
blk_mq_trigger_softirq(rq);
}
static inline bool blk_mq_complete_need_ipi(struct request *rq)