From: Ming Lei <ming.lei@redhat.com>
To: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>,
linux-block@vger.kernel.org, linux-scsi@vger.kernel.org,
linux-nvme@lists.infradead.org
Subject: Re: sorting out the freeze / quiesce mess
Date: Wed, 10 Nov 2021 17:29:26 +0800 [thread overview]
Message-ID: <YYuQ9mhHtDNDVFQ3@T590> (raw)
In-Reply-To: <20211110091407.GA8396@lst.de>
On Wed, Nov 10, 2021 at 10:14:07AM +0100, Christoph Hellwig wrote:
> Hi Jens and Ming,
>
> I've been looking into properly supporting queue freezing for bio based
> drivers (that is only release q_usage_counter on bio completion for them).
> And the deeper I look into the code the more I'm confused by us having
> the blk_mq_quiesce* interface in addition to blk_freeze_queue. What
> is a good reason to do a quiesce separately from a freeze?
freeze can make sure that all requests are done, quiesce can make sure that
dispatch critical area(covered by hctx lock/unlock) is done.
Thanks,
Ming
next prev parent reply other threads:[~2021-11-10 9:29 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-10 9:14 sorting out the freeze / quiesce mess Christoph Hellwig
2021-11-10 9:29 ` Ming Lei [this message]
2021-11-10 9:52 ` Ming Lei
2021-11-10 12:58 ` Christoph Hellwig
2021-11-10 14:56 ` Ming Lei
2021-11-10 10:22 ` Hannes Reinecke
2021-11-10 10:45 ` Ming Lei
2021-11-10 12:32 ` James Bottomley
2021-11-10 13:30 ` Max Gurtovoy
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=YYuQ9mhHtDNDVFQ3@T590 \
--to=ming.lei@redhat.com \
--cc=axboe@kernel.dk \
--cc=hch@lst.de \
--cc=linux-block@vger.kernel.org \
--cc=linux-nvme@lists.infradead.org \
--cc=linux-scsi@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox