Re: [PATCH] Describe race of direct read and fork for unalignedbuffers

From: Mel Gorman
Date: Mon Apr 30 2012 - 10:30:17 EST


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@xxxxxxx
> CC: Jeff Moyer <jmoyer@xxxxxxxxxx>
> Signed-off-by: Jan Kara <jack@xxxxxxx>

Acked-by: Mel Gorman <mgorman@xxxxxxx>

--
Mel Gorman
SUSE Labs
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