From: Christoph Hellwig <hch@lst.de>
To: Ming Lei <ming.lei@redhat.com>
Cc: Will Deacon <will@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Christoph Hellwig <hch@lst.de>, Jens Axboe <axboe@kernel.dk>,
linux-block@vger.kernel.org, John Garry <john.garry@huawei.com>,
Bart Van Assche <bvanassche@acm.org>,
Hannes Reinecke <hare@suse.com>,
Thomas Gleixner <tglx@linutronix.de>,
paulmck@kernel.org
Subject: Re: [PATCH V8 07/11] blk-mq: stop to handle IO and drain IO before hctx becomes inactive
Date: Tue, 5 May 2020 17:46:18 +0200 [thread overview]
Message-ID: <20200505154618.GA3644@lst.de> (raw)
In-Reply-To: <20200430140254.GA996887@T590>
On Thu, Apr 30, 2020 at 10:02:54PM +0800, Ming Lei wrote:
> BLK_MQ_S_INACTIVE is only set when the last cpu of this hctx is becoming
> offline, and blk_mq_hctx_notify_offline() is called from cpu hotplug
> handler. So if there is any request of this hctx submitted from somewhere,
> it has to this last cpu. That is done by blk-mq's queue mapping.
>
> In case of direct issue, basically blk_mq_get_driver_tag() is run after
> the request is allocated, that is why I mentioned the chance of
> migration is very small.
"very small" does not cut it, it has to be zero. And it seems the
new version still has this hack.
next prev parent reply other threads:[~2020-05-05 15:46 UTC|newest]
Thread overview: 80+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-24 10:23 [PATCH V8 00/11] blk-mq: improvement CPU hotplug Ming Lei
2020-04-24 10:23 ` [PATCH V8 01/11] block: clone nr_integrity_segments and write_hint in blk_rq_prep_clone Ming Lei
2020-04-24 10:32 ` Christoph Hellwig
2020-04-24 12:43 ` Hannes Reinecke
2020-04-24 16:11 ` Martin K. Petersen
2020-04-24 10:23 ` [PATCH V8 02/11] block: add helper for copying request Ming Lei
2020-04-24 10:35 ` Christoph Hellwig
2020-04-24 12:43 ` Hannes Reinecke
2020-04-24 16:12 ` Martin K. Petersen
2020-04-24 10:23 ` [PATCH V8 03/11] blk-mq: mark blk_mq_get_driver_tag as static Ming Lei
2020-04-24 12:44 ` Hannes Reinecke
2020-04-24 16:13 ` Martin K. Petersen
2020-04-24 10:23 ` [PATCH V8 04/11] blk-mq: assign rq->tag in blk_mq_get_driver_tag Ming Lei
2020-04-24 10:35 ` Christoph Hellwig
2020-04-24 13:02 ` Hannes Reinecke
2020-04-25 2:54 ` Ming Lei
2020-04-25 18:26 ` Hannes Reinecke
2020-04-24 10:23 ` [PATCH V8 05/11] blk-mq: support rq filter callback when iterating rqs Ming Lei
2020-04-24 13:17 ` Hannes Reinecke
2020-04-25 3:04 ` Ming Lei
2020-04-24 10:23 ` [PATCH V8 06/11] blk-mq: prepare for draining IO when hctx's all CPUs are offline Ming Lei
2020-04-24 13:23 ` Hannes Reinecke
2020-04-25 3:24 ` Ming Lei
2020-04-24 10:23 ` [PATCH V8 07/11] blk-mq: stop to handle IO and drain IO before hctx becomes inactive Ming Lei
2020-04-24 10:38 ` Christoph Hellwig
2020-04-25 3:17 ` Ming Lei
2020-04-25 8:32 ` Christoph Hellwig
2020-04-25 9:34 ` Ming Lei
2020-04-25 9:53 ` Ming Lei
2020-04-25 15:48 ` Christoph Hellwig
2020-04-26 2:06 ` Ming Lei
2020-04-26 8:19 ` John Garry
2020-04-27 15:36 ` Christoph Hellwig
2020-04-28 1:10 ` Ming Lei
2020-04-27 19:03 ` Paul E. McKenney
2020-04-28 6:54 ` Christoph Hellwig
2020-04-28 15:58 ` Peter Zijlstra
2020-04-29 2:16 ` Ming Lei
2020-04-29 8:07 ` Will Deacon
2020-04-29 9:46 ` Ming Lei
2020-04-29 12:27 ` Will Deacon
2020-04-29 13:43 ` Ming Lei
2020-04-29 17:34 ` Will Deacon
2020-04-30 0:39 ` Ming Lei
2020-04-30 11:04 ` Will Deacon
2020-04-30 14:02 ` Ming Lei
2020-05-05 15:46 ` Christoph Hellwig [this message]
2020-05-06 1:24 ` Ming Lei
2020-05-06 7:28 ` Will Deacon
2020-05-06 8:07 ` Ming Lei
2020-05-06 9:56 ` Will Deacon
2020-05-06 10:22 ` Ming Lei
2020-04-29 17:46 ` Paul E. McKenney
2020-04-30 0:43 ` Ming Lei
2020-04-24 13:27 ` Hannes Reinecke
2020-04-25 3:30 ` Ming Lei
2020-04-24 13:42 ` John Garry
2020-04-25 3:41 ` Ming Lei
2020-04-24 10:23 ` [PATCH V8 08/11] block: add blk_end_flush_machinery Ming Lei
2020-04-24 10:41 ` Christoph Hellwig
2020-04-25 3:44 ` Ming Lei
2020-04-25 8:11 ` Christoph Hellwig
2020-04-25 9:51 ` Ming Lei
2020-04-24 13:47 ` Hannes Reinecke
2020-04-25 3:47 ` Ming Lei
2020-04-24 10:23 ` [PATCH V8 09/11] blk-mq: add blk_mq_hctx_handle_dead_cpu for handling cpu dead Ming Lei
2020-04-24 10:42 ` Christoph Hellwig
2020-04-25 3:48 ` Ming Lei
2020-04-24 13:48 ` Hannes Reinecke
2020-04-24 10:23 ` [PATCH V8 10/11] blk-mq: re-submit IO in case that hctx is inactive Ming Lei
2020-04-24 10:44 ` Christoph Hellwig
2020-04-25 3:52 ` Ming Lei
2020-04-24 13:55 ` Hannes Reinecke
2020-04-25 3:59 ` Ming Lei
2020-04-24 10:23 ` [PATCH V8 11/11] block: deactivate hctx when the hctx is actually inactive Ming Lei
2020-04-24 10:43 ` Christoph Hellwig
2020-04-24 13:56 ` Hannes Reinecke
2020-04-24 15:23 ` [PATCH V8 00/11] blk-mq: improvement CPU hotplug Jens Axboe
2020-04-24 15:40 ` Christoph Hellwig
2020-04-24 15:41 ` Jens Axboe
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