From: Andrew Morton <akpm@osdl.org>
To: David Miller <davem@davemloft.net>
Cc: dmonakhov@openvz.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [PATCH] mm:D-cache aliasing issue in cow_user_page
Date: Thu, 19 Oct 2006 00:41:18 -0700 [thread overview]
Message-ID: <20061019004118.37741cad.akpm@osdl.org> (raw)
In-Reply-To: <20061019.002237.130236131.davem@davemloft.net>
On Thu, 19 Oct 2006 00:22:37 -0700 (PDT)
David Miller <davem@davemloft.net> wrote:
> > > Architectures typically take care of this in copy_user_page() and
> > > clear_user_page(). The absolutely depend upon those two routines
> > > being used for anonymous pages, and handle the D-cache issues there.
> >
> > Only anonymous pages? There are zillions of places where we modify
> > pagecache without a flush, especially against the blockdev mapping (fs
> > metadata).
>
> It's cpu stores that matter, not device DMA and the like, and we have
> flush_dcache_page() calls in the correct spots. You can see that
> we take care of this even in places such as the loop driver :-)
grep b_data fs/*/*.c
All of them ;)
It's possible to mmap /dev/hda, but it's a rather odd thing to do (INND
can do it, but not a live filesystem).
--
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:"dont@kvack.org"> email@kvack.org </a>
prev parent reply other threads:[~2006-10-19 7:41 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-10-17 9:15 Dmitriy Monakhov
2006-10-19 6:33 ` Andrew Morton
2006-10-19 7:00 ` David Miller, Andrew Morton
2006-10-19 7:17 ` Andrew Morton
2006-10-19 7:22 ` David Miller, Andrew Morton
2006-10-19 7:41 ` Andrew Morton [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=20061019004118.37741cad.akpm@osdl.org \
--to=akpm@osdl.org \
--cc=davem@davemloft.net \
--cc=dmonakhov@openvz.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.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