From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: linux-block@vger.kernel.org
Cc: Jens Axboe <axboe@kernel.dk>,
Thomas Gleixner <tglx@linutronix.de>,
Peter Zijlstra <peterz@infradead.org>,
Daniel Wagner <dwagner@suse.de>, Mike Galbraith <efault@gmx.de>,
Christoph Hellwig <hch@infradead.org>,
Sagi Grimberg <sagi@grimberg.me>
Subject: [PATCH 0/3 v2] blk-mq: Don't complete in IRQ, use llist_head
Date: Fri, 4 Dec 2020 20:13:53 +0100 [thread overview]
Message-ID: <20201204191356.2516405-1-bigeasy@linutronix.de> (raw)
This a repost of the patches in the old thread [0] which died, rebase against
-next.
The series avoids completing the requests on a remote CPU if booted with
threadirqs. It avoids completing requests in hard-IRQ context on remote
CPU by deferring it to the the softirq context.
One change since the last post: preempt-disable() around llist_add() +
raise_softirq() to ensure that request is added on the same CPU where
the softirq is raised. Some callers (like usb-storage) invoke this
function from preemtible context and this preserves the current "call me
from any context" semantic.
My understanding is that in a later attempt we may change such callers
to complete directly and avoid the softirq ping-pong.
[0] https://lkml.kernel.org/r/20201028141251.3608598-1-bigeasy@linutronix.de
Sebastian
next reply other threads:[~2020-12-04 19:14 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-04 19:13 Sebastian Andrzej Siewior [this message]
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
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
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