From: Bart Van Assche <bvanassche@acm.org>
To: Ming Lei <ming.lei@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>,
linux-block@vger.kernel.org, John Garry <john.garry@huawei.com>,
Hannes Reinecke <hare@suse.com>, Christoph Hellwig <hch@lst.de>,
Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH V10 07/11] blk-mq: stop to handle IO and drain IO before hctx becomes inactive
Date: Sat, 9 May 2020 07:18:46 -0700 [thread overview]
Message-ID: <1918187b-2baa-5703-63ee-097a307cf594@acm.org> (raw)
In-Reply-To: <20200509041042.GG1392681@T590>
On 2020-05-08 21:10, Ming Lei wrote:
> queue freezing can only be applied on the request queue level, and not
> hctx level. When requests can't be completed, wait freezing just hangs
> for-ever.
That's indeed what I meant: freeze the entire queue instead of
introducing a new mechanism that freezes only one hardware queue at a time.
Please clarify what "when requests can't be completed" means. Are you
referring to requests that take longer than expected due to e.g. a
controller lockup or to requests that take a long time intentionally?
The former case is handled by the block layer timeout handler. I propose
to handle the latter case by introducing a new callback function pointer
in struct blk_mq_ops that aborts all outstanding requests. Request queue
freezing is such an important block layer mechanism that I think we
should require that all block drivers support freezing a request queue
in a short time.
Bart.
next prev parent reply other threads:[~2020-05-09 14:18 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-05 2:09 [PATCH V10 00/11] blk-mq: improvement CPU hotplug Ming Lei
2020-05-05 2:09 ` [PATCH V10 01/11] block: clone nr_integrity_segments and write_hint in blk_rq_prep_clone Ming Lei
2020-05-05 2:09 ` [PATCH V10 02/11] block: add helper for copying request Ming Lei
2020-05-05 2:09 ` [PATCH V10 03/11] blk-mq: mark blk_mq_get_driver_tag as static Ming Lei
2020-05-05 2:09 ` [PATCH V10 04/11] blk-mq: assign rq->tag in blk_mq_get_driver_tag Ming Lei
2020-05-05 2:09 ` [PATCH V10 05/11] blk-mq: support rq filter callback when iterating rqs Ming Lei
2020-05-08 23:32 ` Bart Van Assche
2020-05-09 0:18 ` Bart Van Assche
2020-05-09 2:05 ` Ming Lei
2020-05-09 3:08 ` Bart Van Assche
2020-05-09 3:52 ` Ming Lei
2020-05-05 2:09 ` [PATCH V10 06/11] blk-mq: prepare for draining IO when hctx's all CPUs are offline Ming Lei
2020-05-05 6:14 ` Hannes Reinecke
2020-05-08 23:26 ` Bart Van Assche
2020-05-09 2:09 ` Ming Lei
2020-05-09 3:11 ` Bart Van Assche
2020-05-09 3:56 ` Ming Lei
2020-05-05 2:09 ` [PATCH V10 07/11] blk-mq: stop to handle IO and drain IO before hctx becomes inactive Ming Lei
2020-05-08 23:39 ` Bart Van Assche
2020-05-09 2:20 ` Ming Lei
2020-05-09 3:24 ` Bart Van Assche
2020-05-09 4:10 ` Ming Lei
2020-05-09 14:18 ` Bart Van Assche [this message]
2020-05-11 1:45 ` Ming Lei
2020-05-11 3:20 ` Bart Van Assche
2020-05-11 3:48 ` Ming Lei
2020-05-11 20:56 ` Bart Van Assche
2020-05-12 1:25 ` Ming Lei
2020-05-05 2:09 ` [PATCH V10 08/11] block: add blk_end_flush_machinery Ming Lei
2020-05-05 2:09 ` [PATCH V10 09/11] blk-mq: add blk_mq_hctx_handle_dead_cpu for handling cpu dead Ming Lei
2020-05-05 2:09 ` [PATCH V10 10/11] blk-mq: re-submit IO in case that hctx is inactive Ming Lei
2020-05-05 2:09 ` [PATCH V10 11/11] block: deactivate hctx when the hctx is actually inactive Ming Lei
2020-05-09 14:07 ` Bart Van Assche
2020-05-11 2:11 ` Ming Lei
2020-05-11 3:30 ` Bart Van Assche
2020-05-11 4:08 ` Ming Lei
2020-05-11 20:52 ` Bart Van Assche
2020-05-12 1:43 ` Ming Lei
2020-05-12 2:08 ` Ming Lei
2020-05-08 21:49 ` [PATCH V10 00/11] blk-mq: improvement CPU hotplug Ming Lei
2020-05-09 3:17 ` Jens Axboe
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