From: William Lee Irwin III <wli@holomorphy.com>
To: "Paul E. McKenney" <paulmck@us.ibm.com>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, akpm@digeo.com,
mjbligh@us.ibm.com
Subject: Re: [RFC][PATCH] Fix for latent bug in vmtruncate()
Date: Tue, 13 May 2003 15:06:26 -0700 [thread overview]
Message-ID: <20030513220626.GA29926@holomorphy.com> (raw)
In-Reply-To: <20030513135807.E2929@us.ibm.com>
On Tue, May 13, 2003 at 01:58:07PM -0700, Paul E. McKenney wrote:
> The vmtruncate() function shifts down by PAGE_CACHE_SHIFT, then
> calls vmtruncate_list(), which deals in terms of PAGE_SHIFT
> instead. Currently, no harm done, since PAGE_CACHE_SHIFT and
> PAGE_SHIFT are identical. Some day they might not be, hence
> this patch.
> I also took the liberty of modifying a hand-coded "if" that
> seems to optimize for files that are not mapped to instead
> use unlikely().
pgoff describes a file offset in the same units used to map files
with (the size of an area covered by a PTE), which is PAGE_SIZE (in
mainline; elsewhere it's called MMUPAGE_SIZE and I had to fix this
already for my tree). When they differ this would lose the offset into
the PAGE_CACHE_SIZE-sized file page; hence, well-spotted.
-- wli
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"aart@kvack.org"> aart@kvack.org </a>
prev parent reply other threads:[~2003-05-13 22:06 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-05-13 20:58 Paul E. McKenney
2003-05-13 22:06 ` William Lee Irwin III [this message]
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=20030513220626.GA29926@holomorphy.com \
--to=wli@holomorphy.com \
--cc=akpm@digeo.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mjbligh@us.ibm.com \
--cc=paulmck@us.ibm.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