From: Daniel Wagner <dwagner@suse.de>
To: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Jens Axboe <axboe@kernel.dk>,
linux-block@vger.kernel.org, Thomas Gleixner <tglx@linutronix.de>,
Peter Zijlstra <peterz@infradead.org>,
Mike Galbraith <efault@gmx.de>,
Christoph Hellwig <hch@infradead.org>,
Sagi Grimberg <sagi@grimberg.me>, Hannes Reinecke <hare@suse.de>
Subject: Re: [PATCH 2/3] blk-mq: Always complete remote completions requests in softirq
Date: Tue, 8 Dec 2020 14:27:30 +0100 [thread overview]
Message-ID: <20201208132730.pus73xdemgkdq45u@beryllium.lan> (raw)
In-Reply-To: <20201208125709.5epgbpmqp56bf243@linutronix.de>
On Tue, Dec 08, 2020 at 01:57:09PM +0100, Sebastian Andrzej Siewior wrote:
> Yes, you are right. Even cross-CPU completion for single-queue was
> already completing in softirq. So the only change is for multiqueue
> devices which you just demonstrated that it does not happen.
It can happen if there are less hardware queues than CPUs. But I'd bet
that application which care about performance are well aware of this and
try to keep the work vertical aligned.
next prev parent reply other threads:[~2020-12-08 13:28 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-04 19:13 [PATCH 0/3 v2] blk-mq: Don't complete in IRQ, use llist_head Sebastian Andrzej Siewior
2020-12-04 19:13 ` [PATCH 1/3] blk-mq: Don't complete on a remote CPU in force threaded mode Sebastian Andrzej Siewior
2020-12-08 13:10 ` Christoph Hellwig
2020-12-04 19:13 ` [PATCH 2/3] blk-mq: Always complete remote completions requests in softirq Sebastian Andrzej Siewior
2020-12-07 23:52 ` Jens Axboe
2020-12-08 8:22 ` Sebastian Andrzej Siewior
2020-12-08 8:44 ` Daniel Wagner
2020-12-08 11:36 ` Daniel Wagner
2020-12-08 11:49 ` Sebastian Andrzej Siewior
2020-12-08 12:41 ` Daniel Wagner
2020-12-08 12:52 ` Sebastian Andrzej Siewior
2020-12-08 12:57 ` Sebastian Andrzej Siewior
2020-12-08 13:27 ` Daniel Wagner [this message]
2020-12-17 16:45 ` Jens Axboe
2020-12-17 16:49 ` Daniel Wagner
2020-12-17 16:54 ` Jens Axboe
2020-12-08 13:13 ` Christoph Hellwig
2020-12-17 16:43 ` Sebastian Andrzej Siewior
2020-12-17 16:55 ` Jens Axboe
2020-12-17 16:58 ` Sebastian Andrzej Siewior
2020-12-17 17:05 ` Daniel Wagner
2020-12-17 18:16 ` Daniel Wagner
2020-12-17 18:22 ` Jens Axboe
2020-12-17 18:41 ` Daniel Wagner
2020-12-17 18:46 ` Jens Axboe
2020-12-17 19:07 ` Daniel Wagner
2020-12-17 19:13 ` Jens Axboe
2020-12-17 19:15 ` Daniel Wagner
2020-12-04 19:13 ` [PATCH 3/3] blk-mq: Use llist_head for blk_cpu_done Sebastian Andrzej Siewior
2020-12-08 13:20 ` Christoph Hellwig
2020-12-08 13:28 ` Christoph Hellwig
2020-12-14 20:20 ` Sebastian Andrzej Siewior
-- strict thread matches above, loose matches on Subject: below --
2021-01-23 20:10 [PATCH v3 0/3] blk-mq: Don't complete in IRQ, use llist_head Sebastian Andrzej Siewior
2021-01-23 20:10 ` [PATCH 2/3] blk-mq: Always complete remote completions requests in softirq Sebastian Andrzej Siewior
2021-01-25 7:10 ` Hannes Reinecke
2021-01-25 8:25 ` Christoph Hellwig
2021-01-25 8:30 ` Sebastian Andrzej Siewior
2021-01-25 8:32 ` Christoph Hellwig
2021-01-25 9:29 ` Sebastian Andrzej Siewior
2021-01-25 8:22 ` Christoph Hellwig
2021-01-25 8:49 ` Christoph Hellwig
2021-01-27 11:22 ` Daniel Wagner
2020-10-28 6:56 [PATCH RFC] blk-mq: Don't IPI requests on PREEMPT_RT Christoph Hellwig
2020-10-28 14:12 ` [PATCH 1/3] blk-mq: Don't complete on a remote CPU in force threaded mode Sebastian Andrzej Siewior
2020-10-28 14:12 ` [PATCH 2/3] blk-mq: Always complete remote completions requests in softirq Sebastian Andrzej Siewior
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