linux-btrfs.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Christoph Hellwig <hch@infradead.org>
To: Matthew Wilcox <willy@infradead.org>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.de>,
	jack@suse.com, hch@infradead.org, linux-fsdevel@vger.kernel.org,
	linux-block@vger.kernel.org, linux-btrfs@vger.kernel.org,
	linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org,
	Goldwyn Rodrigues <rgoldwyn@suse.com>
Subject: Re: [PATCH 3/8] nowait aio: return if direct write will trigger writeback
Date: Wed, 1 Mar 2017 07:38:57 -0800	[thread overview]
Message-ID: <20170301153857.GC30631@infradead.org> (raw)
In-Reply-To: <20170301034606.GK16328@bombadil.infradead.org>

On Tue, Feb 28, 2017 at 07:46:06PM -0800, Matthew Wilcox wrote:
> Ugh, this is pretty inefficient.  If that's all you want to know, then
> using the radix tree directly will be far more efficient than spinning
> up all the pagevec machinery only to discard the pages found.
> 
> But what's going to kick these pages out of cache?  Shouldn't we rather
> find the pages, kick them out if clean, start writeback if not, and *then*
> return -EAGAIN?
> 
> So maybe we want to spin up the pagevec machinery after all so we can
> do that extra work?

As pointed out in the last round of these patches I think we really
need to pass a flags argument to filemap_write_and_wait_range to
communicate the non-blocking nature and only return -EAGAIN if we'd
block.  As a bonus that can indeed start to kick the pages out.

  reply	other threads:[~2017-03-01 15:39 UTC|newest]

Thread overview: 48+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-02-28 23:36 [PATCH 0/8 v2] Non-blocking AIO Goldwyn Rodrigues
2017-02-28 23:36 ` [PATCH 1/8] nowait aio: Introduce IOCB_FLAG_NOWAIT Goldwyn Rodrigues
2017-03-01 15:36   ` Christoph Hellwig
2017-03-01 15:56     ` Christoph Hellwig
2017-03-01 16:57       ` Goldwyn Rodrigues
2017-03-01 22:44         ` Christoph Hellwig
2017-02-28 23:36 ` [PATCH 2/8] nowait aio: Return if cannot get hold of i_rwsem Goldwyn Rodrigues
2017-03-01 15:37   ` Christoph Hellwig
2017-02-28 23:36 ` [PATCH 3/8] nowait aio: return if direct write will trigger writeback Goldwyn Rodrigues
2017-03-01  3:46   ` Matthew Wilcox
2017-03-01 15:38     ` Christoph Hellwig [this message]
2017-03-02 10:38       ` Jan Kara
2017-03-02 14:12         ` Matthew Wilcox
2017-03-02 15:22           ` Jan Kara
2017-02-28 23:36 ` [PATCH 4/8] nowait aio: Introduce IOMAP_NOWAIT Goldwyn Rodrigues
2017-02-28 23:36 ` [PATCH 5/8] nowait aio: return on congested block device Goldwyn Rodrigues
2017-03-08  7:03   ` Sagi Grimberg
2017-03-08 15:00     ` Goldwyn Rodrigues
2017-03-08 15:28       ` Jan Kara
2017-03-08 15:51         ` Christoph Hellwig
2017-03-08 16:17       ` Jens Axboe
2017-03-09  2:18         ` Goldwyn Rodrigues
2017-02-28 23:36 ` [PATCH 6/8] nowait aio: ext4 Goldwyn Rodrigues
2017-02-28 23:36 ` [PATCH 7/8] nowait aio: xfs Goldwyn Rodrigues
2017-03-01 15:40   ` Christoph Hellwig
2017-02-28 23:36 ` [PATCH 8/8] nowait aio: btrfs Goldwyn Rodrigues
2017-03-05 14:56 ` [PATCH 0/8 v2] Non-blocking AIO Avi Kivity
2017-03-06  8:25   ` Jan Kara
2017-03-06  8:40     ` Avi Kivity
2017-03-06 15:19     ` Jens Axboe
2017-03-06 15:29       ` Avi Kivity
2017-03-06 15:38         ` Jens Axboe
2017-03-06 15:59           ` Avi Kivity
2017-03-06 16:08             ` Jens Axboe
2017-03-06 16:59               ` Avi Kivity
2017-03-06 17:06                 ` Jens Axboe
2017-03-06 18:17                   ` Avi Kivity
2017-03-06 18:27                     ` Jens Axboe
2017-03-06 18:50                       ` Avi Kivity
  -- strict thread matches above, loose matches on Subject: below --
2017-03-15 21:50 [PATCH 0/8 v3] No wait AIO Goldwyn Rodrigues
2017-03-15 21:51 ` [PATCH 3/8] nowait aio: return if direct write will trigger writeback Goldwyn Rodrigues
2017-03-16 13:08   ` Matthew Wilcox
2017-03-16 13:46     ` Goldwyn Rodrigues
2017-03-16 13:20   ` Matthew Wilcox
2017-03-16 13:46     ` Goldwyn Rodrigues
2017-04-03 18:52 [PATCH 0/8 v4] No wait AIO Goldwyn Rodrigues
2017-04-03 18:53 ` [PATCH 3/8] nowait aio: return if direct write will trigger writeback Goldwyn Rodrigues
2017-04-14 12:02 [PATCH 0/8 v6] No wait AIO Goldwyn Rodrigues
2017-04-14 12:02 ` [PATCH 3/8] nowait aio: return if direct write will trigger writeback Goldwyn Rodrigues
2017-05-09 12:22 [PATCH 0/8 v7] No wait AIO Goldwyn Rodrigues
2017-05-09 12:22 ` [PATCH 3/8] nowait aio: return if direct write will trigger writeback Goldwyn Rodrigues
2017-05-11  7:42   ` Christoph Hellwig

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=20170301153857.GC30631@infradead.org \
    --to=hch@infradead.org \
    --cc=jack@suse.com \
    --cc=linux-block@vger.kernel.org \
    --cc=linux-btrfs@vger.kernel.org \
    --cc=linux-ext4@vger.kernel.org \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-xfs@vger.kernel.org \
    --cc=rgoldwyn@suse.com \
    --cc=rgoldwyn@suse.de \
    --cc=willy@infradead.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;
as well as URLs for NNTP newsgroup(s).