From: Nick Piggin <nickpiggin@yahoo.com.au>
To: Tim LaBerge <tim.laberge@quantum.com>
Cc: "Arcangeli, Andrea" <aarcange@redhat.com>,
linux-mm@kvack.org, linux-fsdevel@vger.kernel.org
Subject: Re: Corruption with O_DIRECT and unaligned user buffers
Date: Wed, 19 Nov 2008 17:52:35 +1100 [thread overview]
Message-ID: <200811191752.35497.nickpiggin@yahoo.com.au> (raw)
In-Reply-To: <200811191526.00036.nickpiggin@yahoo.com.au>
On Wednesday 19 November 2008 15:25, Nick Piggin wrote:
> For the moment (and previous kernels up to now), I guess you have to
> be careful about fork and get_user_pages, unfortunately.
I'm reminded by someone wishing to remain anonymous that one of
the ways that we can "be careful", is to use MADV_DONTFORK for
ranges that may be under direct IO.
Not a beautiful solution, but it might work.
If you need some sharing of that region between parent and child,
you could alternatively use a shared mapping (eg. MAP_ANONYMOUS |
MAP_SHARED) and avoid the COW issue completely.
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next prev parent reply other threads:[~2008-11-19 6:52 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-11-14 17:04 Tim LaBerge
2008-11-19 4:25 ` Nick Piggin
2008-11-19 6:52 ` Nick Piggin [this message]
2008-11-19 16:58 ` Andrea Arcangeli
2008-12-18 15:29 ` Andrea Arcangeli
2008-12-19 2:21 ` KAMEZAWA Hiroyuki
2008-12-19 5:06 ` KAMEZAWA Hiroyuki
2008-12-19 6:34 ` KOSAKI Motohiro
2008-12-20 16:02 ` Andrea Arcangeli
2008-12-19 7:19 ` KAMEZAWA Hiroyuki
2008-12-19 7:44 ` Li Zefan
2008-12-19 8:45 ` Li Zefan
2008-12-19 20:27 ` Andrea Arcangeli
2008-12-20 15:55 ` Andrea Arcangeli
2008-12-19 11:51 ` Li Zefan
2008-12-19 12:14 ` KOSAKI Motohiro
2008-12-19 12:58 ` Hugh Dickins
2008-12-19 20:34 ` Andrea Arcangeli
2014-06-27 2:08 Xiaoguang Wang
2014-07-01 4:18 ` Hugh Dickins
2014-07-02 11:39 ` Xiaoguang Wang
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