From: Dave Chinner <david@fromorbit.com>
To: Matthew Wilcox <willy@linux.intel.com>
Cc: linux-fsdevel@vger.kernel.org
Subject: Re: direct_access, pinning and truncation
Date: Thu, 9 Oct 2014 12:10:38 +1100 [thread overview]
Message-ID: <20141009011038.GA4376@dastard> (raw)
In-Reply-To: <20141008190523.GM5098@wil.cx>
On Wed, Oct 08, 2014 at 03:05:23PM -0400, Matthew Wilcox wrote:
>
> One of the things on my todo list is making O_DIRECT work to a
> memory-mapped direct_access file.
I don't understand the motivation or the use case: O_DIRECT is
purely for bypassing the page cache, and DAX already bypasses the
page cache. What difference is there between the DAX read/write
path and a DAX-based O_DIRECT IO path, and why doesn't just ignoring
O_DIRECT for DAX enabled filesystems simply do what you need?
Cheers,
Dave.
--
Dave Chinner
david@fromorbit.com
next prev parent reply other threads:[~2014-10-09 1:10 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-08 19:05 direct_access, pinning and truncation Matthew Wilcox
2014-10-08 23:21 ` Zach Brown
2014-10-09 16:44 ` Matthew Wilcox
2014-10-09 19:14 ` Zach Brown
2014-10-10 10:01 ` Jan Kara
2014-10-09 1:10 ` Dave Chinner [this message]
2014-10-09 15:25 ` Matthew Wilcox
2014-10-13 1:19 ` Dave Chinner
2014-10-19 9:51 ` Boaz Harrosh
2014-10-10 13:08 ` Jan Kara
2014-10-10 14:24 ` Matthew Wilcox
2014-10-19 11:08 ` Boaz Harrosh
2014-10-19 23:01 ` Dave Chinner
2014-10-21 9:17 ` Boaz Harrosh
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