All of lore.kernel.org
 help / color / mirror / Atom feed
From: Matthew Wilcox <willy@debian.org>
To: Mark B <mark@lemna.hr>
Cc: Matthew Wilcox <willy@debian.org>, linux-fsdevel@vger.kernel.org
Subject: Re: same page access
Date: Wed, 22 Oct 2003 18:10:32 +0100	[thread overview]
Message-ID: <20031022171032.GS18370@parcelfarce.linux.theplanet.co.uk> (raw)
In-Reply-To: <200310221909.58066.mark@lemna.hr>

On Wed, Oct 22, 2003 at 07:09:58PM +0200, Mark B wrote:
> Mmm sorry I formulated the question a bit wrong, here's the correction;
> I know that the data what was read() before the write() can't be affected, 
> it's a perfectly normal condition, but I'm talking about the page of data the 
> kernel loaded in the VFS for that file handle, is the data the same copy of 
> data that is served to other processes? So a read() by P1 after P2 has did a 
> write() in the same area, will it lead to a reload of the page since the P2 
> marked the area dirty? Or simply they're working on the same memory page? Is 
> there any locking (by commit_write()?)

They're working from the same memory page (in the page cache).  This same
page is also shared with any process that has a shared mmap.

-- 
"It's not Hollywood.  War is real, war is primarily not about defeat or
victory, it is about death.  I've seen thousands and thousands of dead bodies.
Do you think I want to have an academic debate on this subject?" -- Robert Fisk

  reply	other threads:[~2003-10-22 17:10 UTC|newest]

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2003-10-07 19:02 zeroes read back more often than appended Pat LaVarre
2003-10-07 20:54 ` Pat LaVarre
2003-10-08  3:49 ` Ben Fennema
2003-10-08 16:41   ` Pat LaVarre
2003-10-08 16:47     ` editable udf metadata Pat LaVarre
2003-10-08 17:51       ` Pat LaVarre
2003-10-08 18:09         ` big-endian udfct_1_0r2 Pat LaVarre
2003-10-08 18:30           ` Matthew Wilcox
     [not found]             ` <3F8472FE.9040403@lougher.demon.co.uk>
2003-10-08 19:49               ` Matthew Wilcox
2003-10-08 20:43             ` Phillip Lougher
2003-10-21 21:54         ` editable udf metadata Pat LaVarre
2003-10-21 23:17           ` Pat LaVarre
2003-10-23 16:06             ` Pat LaVarre
2003-10-24 21:40               ` Pat LaVarre
2003-10-22  8:15           ` same page access Mark B
2003-10-22 11:21             ` Matthew Wilcox
2003-10-22 17:09               ` Mark B
2003-10-22 17:10                 ` Matthew Wilcox [this message]
2003-10-08 17:02     ` zeroes read back more often than appended Pat LaVarre
2003-10-08 17:06       ` toggling smp clears x86_mce_p4thermal of make xconfig Pat LaVarre
2003-10-08 17:21     ` zeroes read back more often than appended Pat LaVarre
2003-10-08 16:46   ` soft trace of read/write of drivers/block/loop.c Pat LaVarre
2003-10-08 20:32   ` zeroes read back more often than appended Pat LaVarre
2003-10-09 20:54   ` Pat LaVarre
2003-10-10  0:52     ` Pat LaVarre
2003-10-10 16:39       ` Pat LaVarre
2003-10-10 18:15         ` Pat LaVarre
2003-10-14  0:38           ` Pat LaVarre
2003-10-14  1:48             ` Pat LaVarre
2003-10-20 23:20               ` Pat LaVarre
2003-10-21 14:47                 ` Pat LaVarre
2003-10-21 16:46                   ` Pat LaVarre
2003-10-21 18:44                     ` Pat LaVarre
2003-10-23 18:52                     ` Pat LaVarre
2003-10-27 21:55                       ` Pat LaVarre

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=20031022171032.GS18370@parcelfarce.linux.theplanet.co.uk \
    --to=willy@debian.org \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=mark@lemna.hr \
    /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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.