From: Christoph Hellwig <hch@lst.de>
To: Bart Van Assche <bvanassche@acm.org>
Cc: Damien Le Moal <dlemoal@kernel.org>, Jens Axboe <axboe@kernel.dk>,
linux-block@vger.kernel.org, Jaegeuk Kim <jaegeuk@kernel.org>,
Christoph Hellwig <hch@lst.de>, Ming Lei <ming.lei@redhat.com>,
Mike Snitzer <snitzer@kernel.org>
Subject: Re: [PATCH v2 09/12] block: mq-deadline: Disable head insertion for zoned writes
Date: Tue, 11 Apr 2023 08:44:08 +0200 [thread overview]
Message-ID: <20230411064408.GB19616@lst.de> (raw)
In-Reply-To: <a3355a43-6c2e-005e-06cc-a050a75ad623@acm.org>
On Mon, Apr 10, 2023 at 10:09:40AM -0700, Bart Van Assche wrote:
> The code for deciding whether or not to use head insertion is spread all
> over the block layer. I prefer a single additional check to disable head
> insertion instead of modifying all the code that decides whether or not to
> use head-insertion. Additionally, the call to blk_rq_is_seq_zoned_write()
> would remain if the decision whether or not to use head insertion is moved
> into the callers of elevator_type.insert_request.
I think it's time to do a proper audit and sort this out.
at_head insertations make absolute sense for certain passthrough commands,
so the path in from blk_execute_rq/blk_execute_rq_nowait is fine, and it
should always be passed on, even for zoned devices.
For everything else head insertations looks very questionable and I
think we need to go through them and figure out if any of them should
be kept.
next prev parent reply other threads:[~2023-04-11 6:44 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-04-07 23:58 [PATCH v2 00/12] Submit zoned writes in order Bart Van Assche
2023-04-07 23:58 ` [PATCH v2 01/12] block: Send zoned writes to the I/O scheduler Bart Van Assche
2023-04-10 7:42 ` Damien Le Moal
2023-04-10 16:35 ` Bart Van Assche
2023-04-07 23:58 ` [PATCH v2 02/12] block: Send flush requests " Bart Van Assche
2023-04-10 7:46 ` Damien Le Moal
2023-04-11 0:15 ` Bart Van Assche
2023-04-11 6:38 ` Christoph Hellwig
2023-04-11 17:13 ` Bart Van Assche
2023-04-07 23:58 ` [PATCH v2 03/12] block: Send requeued " Bart Van Assche
2023-04-10 7:53 ` Damien Le Moal
2023-04-10 16:59 ` Bart Van Assche
2023-04-11 12:38 ` Christoph Hellwig
2023-04-11 17:17 ` Bart Van Assche
2023-04-11 13:14 ` Christoph Hellwig
2023-04-07 23:58 ` [PATCH v2 04/12] block: Requeue requests if a CPU is unplugged Bart Van Assche
2023-04-10 7:54 ` Damien Le Moal
2023-04-11 12:40 ` Christoph Hellwig
2023-04-11 17:18 ` Bart Van Assche
2023-04-07 23:58 ` [PATCH v2 05/12] block: One requeue list per hctx Bart Van Assche
2023-04-10 7:58 ` Damien Le Moal
2023-04-10 17:04 ` Bart Van Assche
2023-04-07 23:58 ` [PATCH v2 06/12] block: Preserve the order of requeued requests Bart Van Assche
2023-04-10 8:01 ` Damien Le Moal
2023-04-11 12:43 ` Christoph Hellwig
2023-04-07 23:58 ` [PATCH v2 07/12] block: Make it easier to debug zoned write reordering Bart Van Assche
2023-04-10 8:06 ` Damien Le Moal
2023-04-07 23:58 ` [PATCH v2 08/12] block: mq-deadline: Simplify deadline_skip_seq_writes() Bart Van Assche
2023-04-10 8:07 ` Damien Le Moal
2023-04-07 23:58 ` [PATCH v2 09/12] block: mq-deadline: Disable head insertion for zoned writes Bart Van Assche
2023-04-10 8:10 ` Damien Le Moal
2023-04-10 17:09 ` Bart Van Assche
2023-04-11 6:44 ` Christoph Hellwig [this message]
2023-04-07 23:58 ` [PATCH v2 10/12] block: mq-deadline: Introduce a local variable Bart Van Assche
2023-04-10 8:11 ` Damien Le Moal
2023-04-07 23:58 ` [PATCH v2 11/12] block: mq-deadline: Fix a race condition related to zoned writes Bart Van Assche
2023-04-10 8:16 ` Damien Le Moal
2023-04-10 17:23 ` Bart Van Assche
2023-04-07 23:58 ` [PATCH v2 12/12] block: mq-deadline: Handle requeued requests correctly Bart Van Assche
2023-04-10 8:32 ` Damien Le Moal
2023-04-10 17:31 ` Bart Van Assche
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