From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx171.postini.com [74.125.245.171]) by kanga.kvack.org (Postfix) with SMTP id 413776B0044 for ; Mon, 30 Apr 2012 10:30:08 -0400 (EDT) Date: Mon, 30 Apr 2012 15:30:04 +0100 From: Mel Gorman Subject: Re: [PATCH] Describe race of direct read and fork for unaligned buffers Message-ID: <20120430143004.GP9226@suse.de> References: <1335778207-6511-1-git-send-email-jack@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <1335778207-6511-1-git-send-email-jack@suse.cz> Sender: owner-linux-mm@kvack.org List-ID: To: Jan Kara Cc: Michael Kerrisk , LKML , linux-man@vger.kernel.org, linux-mm@kvack.org, Jeff Moyer On Mon, Apr 30, 2012 at 11:30:07AM +0200, Jan Kara wrote: > This is a long standing problem (or a surprising feature) in our implementation > of get_user_pages() (used by direct IO). Since several attempts to fix it > failed (e.g. > http://linux.derkeiler.com/Mailing-Lists/Kernel/2009-04/msg06542.html, or > http://lkml.indiana.edu/hypermail/linux/kernel/0903.1/01498.html refused in > http://comments.gmane.org/gmane.linux.kernel.mm/31569) and it's not completely > clear whether we really want to fix it given the costs, let's at least document > it. > > CC: mgorman@suse.de > CC: Jeff Moyer > Signed-off-by: Jan Kara Acked-by: Mel Gorman -- Mel Gorman SUSE Labs -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org