From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
To: Andrew Morton <akpm@linux-foundation.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-mm@kvack.org, linux-fsdevel@vger.kernel.org,
linux-kernel@vger.kernel.org,
Wu Fengguang <fengguang.wu@intel.com>, Jan Kara <jack@suse.cz>,
Nick Piggin <npiggin@kernel.dk>,
Andrea Arcangeli <aarcange@redhat.com>,
Andi Kleen <ak@linux.intel.com>,
"Kirill A. Shutemov" <kirill@shutemov.name>
Subject: PAGE_CACHE_SIZE vs. PAGE_SIZE
Date: Fri, 18 Jan 2013 17:57:25 +0200 [thread overview]
Message-ID: <20130118155724.GA8507@otc-wbsnb-06> (raw)
[-- Attachment #1: Type: text/plain, Size: 726 bytes --]
Hi,
PAGE_CACHE_* macros were introduced long time ago in hope to implement
page cache with larger chunks than one page in future.
In fact it was never done.
Some code paths assume PAGE_CACHE_SIZE <= PAGE_SIZE. E.g. we use
zero_user_segments() to clear stale parts of page on cache filling, but
the function is implemented only for individual small page.
It's unlikely that global switch to PAGE_CACHE_SIZE > PAGE_SIZE will never
happen since it will affect to much code at once.
I think support of larger chunks in page cache can be in implemented in
some form of THP with per-fs enabling.
Is it time to get rid of PAGE_CACHE_* macros?
I can prepare patchset if it's okay.
--
Kirill A. Shutemov
[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 836 bytes --]
next reply other threads:[~2013-01-18 15:57 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-18 15:57 Kirill A. Shutemov [this message]
2013-01-31 22:40 ` PAGE_CACHE_SIZE vs. PAGE_SIZE Andrew Morton
2013-02-19 16:12 ` Michel Lespinasse
2013-02-19 10:32 ` Simon Jeons
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=20130118155724.GA8507@otc-wbsnb-06 \
--to=kirill.shutemov@linux.intel.com \
--cc=aarcange@redhat.com \
--cc=ak@linux.intel.com \
--cc=akpm@linux-foundation.org \
--cc=fengguang.wu@intel.com \
--cc=jack@suse.cz \
--cc=kirill@shutemov.name \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=npiggin@kernel.dk \
--cc=torvalds@linux-foundation.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).