linux-block.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Ming Lei <ming.lei@redhat.com>
To: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>,
	linux-block@vger.kernel.org, Jeff Moyer <jmoyer@redhat.com>,
	Mike Snitzer <snitzer@redhat.com>
Subject: Re: [PATCH 1/4] nvme-pci: correct mapping for poll queue(s)
Date: Mon, 17 Dec 2018 09:00:52 +0800	[thread overview]
Message-ID: <20181217010051.GA1223@ming.t460p> (raw)
In-Reply-To: <20181216161159.GB9957@lst.de>

On Sun, Dec 16, 2018 at 05:11:59PM +0100, Christoph Hellwig wrote:
> On Sun, Dec 16, 2018 at 10:25:14AM +0800, Ming Lei wrote:
> > If we don't have poll queue, its mapping should share default type's,
> > instead of setting up one new mapping via blk_mq_map_queues().
> 
> No, if we don't have poll queues nr_maps should be 2.  I've already
> posted a patch for that for nvme-pci which got it wrong (my fault..)

This patch doesn't touch nr_maps.

The issue is that if poll_queues/write_queues are zero, all three mapping
should be same, however they aren't actually because we still use blk_mq_map_queues()
to build a new mapping for poll queue.

This difference causes broken mapping especially with help of blk_mq_map_swqueue(), since
hctx->type could be re-written.

Thanks,
Ming

  reply	other threads:[~2018-12-17  1:01 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-12-16  2:25 [PATCH 0/4] blk-mq: queue mapping fix & improvement Ming Lei
2018-12-16  2:25 ` [PATCH 1/4] nvme-pci: correct mapping for poll queue(s) Ming Lei
2018-12-16 16:11   ` Christoph Hellwig
2018-12-17  1:00     ` Ming Lei [this message]
2018-12-17  7:06       ` Christoph Hellwig
2018-12-17  7:22         ` Ming Lei
2018-12-16  2:25 ` [PATCH 2/4] blk-mq: fix allocation for queue mapping table Ming Lei
2018-12-16 16:15   ` Christoph Hellwig
2018-12-16  2:25 ` [PATCH 3/4] blk-mq: deal with shared queue mapping reliably Ming Lei
2018-12-16 16:16   ` Christoph Hellwig
2018-12-16 18:39     ` Mike Snitzer
2018-12-16 19:12       ` Jens Axboe
2018-12-17  1:04         ` Ming Lei
2018-12-17  7:44           ` Christoph Hellwig
2018-12-17  8:38             ` Ming Lei
2018-12-17  1:27     ` Ming Lei
2018-12-16  2:25 ` [PATCH 4/4] blk-mq-debugfs: export hctx->type Ming Lei
2018-12-16 16:17   ` Christoph Hellwig
2018-12-16 19:12     ` Jens Axboe
2018-12-17  1:06     ` Ming Lei

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=20181217010051.GA1223@ming.t460p \
    --to=ming.lei@redhat.com \
    --cc=axboe@kernel.dk \
    --cc=hch@lst.de \
    --cc=jmoyer@redhat.com \
    --cc=linux-block@vger.kernel.org \
    --cc=snitzer@redhat.com \
    /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;
as well as URLs for NNTP newsgroup(s).