linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Jan Kara <jack@suse.cz>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: <linux-mm@kvack.org>, Matthew Wilcox <willy@infradead.org>,
	<linux-fsdevel@vger.kernel.org>, Jan Kara <jack@suse.cz>
Subject: [PATCH 0/2] readahead: Reintroduce fix for improper RA window sizing
Date: Wed,  4 Dec 2024 19:10:14 +0100	[thread overview]
Message-ID: <20241204181016.15273-1-jack@suse.cz> (raw)

Hello,

this small patch series reintroduces a fix of readahead window confusion (and
thus read throughput reduction) when page_cache_ra_order() ends up failing due
to folios already present in the page cache. After thinking about this for
a while I have ended up with a dumb fix that just rechecks if we have something
to read before calling do_page_cache_ra(). This fixes the problem reported in
[1]. I still think it doesn't make much sense to update readahead window size
in read_pages() so patch 1 removes that but the real fix in patch 2 does not
depend on it.

Patches are based on top of my revert that's in MM tree as of today but I
expect it lands in Linus' tree very soon.

								Honza

[1] https://lore.kernel.org/all/49648605-d800-4859-be49-624bbe60519d@gmail.com


             reply	other threads:[~2024-12-04 18:10 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-12-04 18:10 Jan Kara [this message]
2024-12-04 18:10 ` [PATCH 1/2] readahead: Don't shorted readahead window in read_pages() Jan Kara
2024-12-04 18:10 ` [PATCH 2/2] readahead: properly shorten readahead when falling back to do_page_cache_ra() Jan Kara

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=20241204181016.15273-1-jack@suse.cz \
    --to=jack@suse.cz \
    --cc=akpm@linux-foundation.org \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --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