From: Kent Overstreet <kent.overstreet@gmail.com>
To: linux-kernel@vger.kernel.org, akpm@linux-foundation.org,
viro@zeniv.linux.org.uk, linux-mm@kvack.org,
linux-fsdevel@vger.kernel.org
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Subject: [PATCH 0/2] generic_file_buffered_read() refactoring & optimization
Date: Tue, 9 Jun 2020 20:10:34 -0400 [thread overview]
Message-ID: <20200610001036.3904844-1-kent.overstreet@gmail.com> (raw)
This is a small patch series that's been in the bcachefs tree for awhile.
In the buffered read path, we look up a page in the page cache, then copy from
that page in a loop - i.e. mixing the data copies in between looking up each
individual page. When we're doing large reads from the page cache, this is some
pretty major overhead.
This just reworks generic_file_buffered_read() to use find_get_pages_contig()
and work on an array of pages. It's a pretty significant performance
improvement for large buffered reads, and doesn't regress performance on single
page reads.
As a bonus, generic_file_buffered_read() gets broken up into multiple functions
that are _somewhat_ easier to follow.
Kent Overstreet (2):
fs: Break generic_file_buffered_read up into multiple functions
fs: generic_file_buffered_read() now uses find_get_pages_contig
mm/filemap.c | 486 +++++++++++++++++++++++++++++----------------------
1 file changed, 273 insertions(+), 213 deletions(-)
--
2.27.0
next reply other threads:[~2020-06-10 0:11 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-10 0:10 Kent Overstreet [this message]
2020-06-10 0:10 ` [PATCH 1/2] fs: Break generic_file_buffered_read up into multiple functions Kent Overstreet
2020-06-10 0:10 ` [PATCH 2/2] fs: generic_file_buffered_read() now uses find_get_pages_contig Kent Overstreet
2020-06-10 0:47 ` Matthew Wilcox
2020-06-10 1:08 ` Kent Overstreet
2020-06-10 1:38 ` Matthew Wilcox
2020-06-10 1:46 ` Kent Overstreet
2020-06-10 1:36 ` [PATCH v2 1/2] fs: Break generic_file_buffered_read up into multiple functions Kent Overstreet
2020-06-10 1:36 ` [PATCH v2 2/2] fs: generic_file_buffered_read() now uses find_get_pages_contig Kent Overstreet
2020-06-18 1:05 ` Andrew Morton
2020-06-19 3:20 ` [PATCH v3 0/2] generic_file_buffered_read() refactoring & optimization Kent Overstreet
2020-06-19 12:59 ` Christoph Hellwig
2020-06-19 18:44 ` Kent Overstreet
2020-06-19 3:20 ` [PATCH v3 1/2] fs: Break generic_file_buffered_read up into multiple functions Kent Overstreet
2020-06-19 3:20 ` [PATCH v3 2/2] fs: generic_file_buffered_read() now uses find_get_pages_contig Kent Overstreet
2020-06-30 0:12 ` Fixup patch for [PATCH 0/2] generic_file_buffered_read() refactoring & optimization Kent Overstreet
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=20200610001036.3904844-1-kent.overstreet@gmail.com \
--to=kent.overstreet@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=viro@zeniv.linux.org.uk \
/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).