From: Christoph Hellwig <hch@infradead.org>
To: Josef Bacik <jbacik@fusionio.com>
Cc: linux-fsdevel@vger.kernel.org, viro@ZenIV.linux.org.uk,
jmoyer@redhat.com, zab@redhat.com
Subject: Re: [PATCH] direct-io: allow file systems to do their own waiting for io
Date: Mon, 3 Dec 2012 10:41:25 -0500 [thread overview]
Message-ID: <20121203154125.GA13344@infradead.org> (raw)
In-Reply-To: <1354541840-1483-1-git-send-email-jbacik@fusionio.com>
On Mon, Dec 03, 2012 at 08:37:20AM -0500, Josef Bacik wrote:
> Btrfs is terrible with O_DIRECT|O_SYNC, mostly because of the constant
> waiting. The thing is we have a handy way of waiting for IO that we can
> delay to the very last second so we do all of the O_SYNC work and then wait
> for a bunch of IO to complete. So introduce a flag to allow the generic
> direct io stuff to forgo waiting and leave that up to the file system.
> Thanks,
I don't really like passing another flag for this, if we we are going to
do something like this it should be in a way where:
- the actualy waiting code is a helper that btrfs would also use
- the main dio code is structured in a way that we have a lower level
entry point that skips the waiting, and a higher level one that also
calls it.
That beeing said I'm not imaginative enough to see how you're actually
going to use it. Posting the btrfs side would help with that.
next prev parent reply other threads:[~2012-12-03 15:41 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-12-03 13:37 [PATCH] direct-io: allow file systems to do their own waiting for io Josef Bacik
2012-12-03 15:41 ` Christoph Hellwig [this message]
2012-12-03 16:14 ` Josef Bacik
2012-12-08 12:17 ` Christoph Hellwig
2012-12-08 12:35 ` Chris Mason
2012-12-14 13:44 ` Chris Mason
2012-12-11 10:00 ` Liu Bo
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