From: John Garry <john.garry@huawei.com>
To: Christoph Hellwig <hch@lst.de>
Cc: <linux-block@vger.kernel.org>,
Bart Van Assche <bvanassche@acm.org>,
Hannes Reinecke <hare@suse.com>,
Thomas Gleixner <tglx@linutronix.de>
Subject: Re: blk-mq: improvement CPU hotplug (simplified version) v2
Date: Mon, 18 May 2020 12:49:14 +0100 [thread overview]
Message-ID: <6241656e-0bf7-b32d-493e-e3f870a4d031@huawei.com> (raw)
In-Reply-To: <20200518063937.757218-1-hch@lst.de>
On 18/05/2020 07:39, Christoph Hellwig wrote:
> Hi all,
>
> this series ensures I/O is quiesced before a cpu and thus the managed
> interrupt handler is shut down.
>
> This patchset tries to address the issue by the following approach:
>
> - before the last cpu in hctx->cpumask is going to offline, mark this
> hctx as inactive
>
> - disable preempt during allocating tag for request, and after tag is
> allocated, check if this hctx is inactive. If yes, give up the
> allocation and try remote allocation from online CPUs
>
> - before hctx becomes inactive, drain all allocated requests on this
> hctx
>
> The guts of the changes are from Ming Lei, I just did a bunch of prep
> cleanups so that they can fit in more nicely. The series also depends
> on my "avoid a few q_usage_counter roundtrips v3" series.
>
> Thanks John Garry for running lots of tests on arm64 with this previous
> version patches and co-working on investigating all kinds of issues.
>
> A git tree is available here:
>
> git://git.infradead.org/users/hch/block.git blk-mq-hotplug
>
> Gitweb:
>
> http://git.infradead.org/users/hch/block.git/shortlog/refs/heads/blk-mq-hotplug
> .
>
FWIW, I tested this series for cpu hotplug and it looked ok.
john
next prev parent reply other threads:[~2020-05-18 11:50 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-18 6:39 blk-mq: improvement CPU hotplug (simplified version) v2 Christoph Hellwig
2020-05-18 6:39 ` [PATCH 1/9] blk-mq: split out a __blk_mq_get_driver_tag helper Christoph Hellwig
2020-05-18 6:39 ` [PATCH 2/9] blk-mq: remove the bio argument to ->prepare_request Christoph Hellwig
2020-05-18 6:39 ` [PATCH 3/9] blk-mq: simplify the blk_mq_get_request calling convention Christoph Hellwig
2020-05-18 6:39 ` [PATCH 4/9] blk-mq: merge blk_mq_rq_ctx_init into __blk_mq_alloc_request Christoph Hellwig
2020-05-18 6:39 ` [PATCH 5/9] blk-mq: don't set data->ctx and data->hctx in blk_mq_alloc_request_hctx Christoph Hellwig
2020-05-18 8:32 ` Thomas Gleixner
2020-05-18 9:31 ` Ming Lei
2020-05-18 10:42 ` Thomas Gleixner
2020-05-18 11:54 ` Ming Lei
2020-05-18 13:16 ` Christoph Hellwig
2020-05-18 14:11 ` Ming Lei
2020-05-18 16:56 ` Christoph Hellwig
2020-05-18 18:38 ` Thomas Gleixner
2020-05-18 18:45 ` Christoph Hellwig
2020-05-18 18:59 ` Thomas Gleixner
2020-05-19 1:54 ` Ming Lei
2020-05-19 15:30 ` Christoph Hellwig
2020-05-20 1:18 ` Ming Lei
2020-05-20 3:04 ` Ming Lei
2020-05-20 8:03 ` io_uring vs CPU hotplug, was " Christoph Hellwig
2020-05-20 14:45 ` Jens Axboe
2020-05-20 15:20 ` Jens Axboe
2020-05-20 15:31 ` Christoph Hellwig
2020-05-20 19:41 ` Thomas Gleixner
2020-05-20 20:18 ` Jens Axboe
2020-05-20 22:14 ` Thomas Gleixner
2020-05-20 22:40 ` Jens Axboe
2020-05-21 2:27 ` Ming Lei
2020-05-21 8:13 ` Thomas Gleixner
2020-05-21 9:23 ` Ming Lei
2020-05-21 18:39 ` Thomas Gleixner
2020-05-21 18:45 ` Jens Axboe
2020-05-21 20:00 ` Thomas Gleixner
2020-05-22 1:57 ` Ming Lei
2020-05-18 18:47 ` Thomas Gleixner
2020-05-18 13:18 ` Thomas Gleixner
2020-05-18 6:39 ` [PATCH 6/9] blk-mq: don't set data->ctx and data->hctx in __blk_mq_alloc_request Christoph Hellwig
2020-05-18 6:39 ` [PATCH 7/9] blk-mq: disable preemption during allocating request tag Christoph Hellwig
2020-05-18 6:39 ` [PATCH 8/9] blk-mq: add blk_mq_all_tag_iter Christoph Hellwig
2020-05-18 6:39 ` [PATCH 9/9] blk-mq: drain I/O when all CPUs in a hctx are offline Christoph Hellwig
2020-05-18 8:42 ` John Garry
2020-05-18 9:21 ` Ming Lei
2020-05-18 11:49 ` John Garry [this message]
2020-05-19 15:30 ` blk-mq: improvement CPU hotplug (simplified version) v2 Christoph Hellwig
2020-05-19 17:17 ` John Garry
2020-05-20 14:35 ` John Garry
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