All of lore.kernel.org
 help / color / mirror / Atom feed
From: Uday Shankar <ushankar@purestorage.com>
To: Christoph Hellwig <hch@infradead.org>
Cc: Jens Axboe <axboe@kernel.dk>,
	linux-block@vger.kernel.org, dm-devel@redhat.com,
	Mike Snitzer <snitzer@kernel.org>,
	Alasdair Kergon <agk@redhat.com>
Subject: Re: [dm-devel] [PATCH] blk-mq: enforce op-specific segment limits in blk_insert_cloned_request
Date: Thu, 16 Feb 2023 12:27:02 -0700	[thread overview]
Message-ID: <20230216192702.GA801590@dev-ushankar.dev.purestorage.com> (raw)
In-Reply-To: <Y+3IoOd02iFGNLnC@infradead.org>

On Wed, Feb 15, 2023 at 10:09:36PM -0800, Christoph Hellwig wrote:
> I'd just remove the debug check entirely

Older kernels have these checks in a separate function called
blk_cloned_rq_check_limits, which carries the following comment:

/**
 * blk_cloned_rq_check_limits - Helper function to check a cloned request
 *                              for the new queue limits
 * @q:  the queue
 * @rq: the request being checked
 *
 * Description:
 *    @rq may have been made based on weaker limitations of upper-level queues
 *    in request stacking drivers, and it may violate the limitation of @q.
 *    Since the block layer and the underlying device driver trust @rq
 *    after it is inserted to @q, it should be checked against @q before
 *    the insertion using this generic function.
 *
 *    Request stacking drivers like request-based dm may change the queue
 *    limits when retrying requests on other queues. Those requests need
 *    to be checked against the new queue limits again during dispatch.
 */.

Is this concern no longer relevant?

--
dm-devel mailing list
dm-devel@redhat.com
https://listman.redhat.com/mailman/listinfo/dm-devel


WARNING: multiple messages have this Message-ID (diff)
From: Uday Shankar <ushankar@purestorage.com>
To: Christoph Hellwig <hch@infradead.org>
Cc: Jens Axboe <axboe@kernel.dk>, Alasdair Kergon <agk@redhat.com>,
	Mike Snitzer <snitzer@kernel.org>,
	linux-block@vger.kernel.org, dm-devel@redhat.com
Subject: Re: [PATCH] blk-mq: enforce op-specific segment limits in blk_insert_cloned_request
Date: Thu, 16 Feb 2023 12:27:02 -0700	[thread overview]
Message-ID: <20230216192702.GA801590@dev-ushankar.dev.purestorage.com> (raw)
In-Reply-To: <Y+3IoOd02iFGNLnC@infradead.org>

On Wed, Feb 15, 2023 at 10:09:36PM -0800, Christoph Hellwig wrote:
> I'd just remove the debug check entirely

Older kernels have these checks in a separate function called
blk_cloned_rq_check_limits, which carries the following comment:

/**
 * blk_cloned_rq_check_limits - Helper function to check a cloned request
 *                              for the new queue limits
 * @q:  the queue
 * @rq: the request being checked
 *
 * Description:
 *    @rq may have been made based on weaker limitations of upper-level queues
 *    in request stacking drivers, and it may violate the limitation of @q.
 *    Since the block layer and the underlying device driver trust @rq
 *    after it is inserted to @q, it should be checked against @q before
 *    the insertion using this generic function.
 *
 *    Request stacking drivers like request-based dm may change the queue
 *    limits when retrying requests on other queues. Those requests need
 *    to be checked against the new queue limits again during dispatch.
 */.

Is this concern no longer relevant?

  reply	other threads:[~2023-02-16 19:27 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-02-15 20:15 [dm-devel] [PATCH] blk-mq: enforce op-specific segment limits in blk_insert_cloned_request Uday Shankar
2023-02-15 20:15 ` Uday Shankar
2023-02-16  6:09 ` [dm-devel] " Christoph Hellwig
2023-02-16  6:09   ` Christoph Hellwig
2023-02-16 19:27   ` Uday Shankar [this message]
2023-02-16 19:27     ` Uday Shankar
2023-02-17  0:13     ` [dm-devel] " Mike Snitzer
2023-02-17  0:13       ` Mike Snitzer
2023-02-17 16:16     ` [dm-devel] [PATCH] " Christoph Hellwig
2023-02-17 16:16       ` Christoph Hellwig
2023-02-17 16:43       ` [dm-devel] " Mike Snitzer
2023-02-17 16:43         ` Mike Snitzer
2023-02-17 21:41         ` [dm-devel] " Uday Shankar
2023-02-17 21:41           ` Uday Shankar
2023-02-16 13:06 ` [dm-devel] [PATCH] " kernel test robot
2023-02-16 13:06   ` kernel test robot

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=20230216192702.GA801590@dev-ushankar.dev.purestorage.com \
    --to=ushankar@purestorage.com \
    --cc=agk@redhat.com \
    --cc=axboe@kernel.dk \
    --cc=dm-devel@redhat.com \
    --cc=hch@infradead.org \
    --cc=linux-block@vger.kernel.org \
    --cc=snitzer@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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.