From mboxrd@z Thu Jan  1 00:00:00 1970
From: Pekka Enberg <penberg@kernel.org>
Subject: RE: [RFC v2 PATCH] kvm tools, qcow: Add the support for
 copy-on-write clusters
Date: Sun, 20 Nov 2011 12:59:31 +0200
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Cc: "Lan, Tianyu" <tianyu.lan@intel.com>,
	Kevin Wolf <kwolf@redhat.com>,
	"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
	"asias.hejun@gmail.com" <asias.hejun@gmail.com>,
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To: Sasha Levin <levinsasha928@gmail.com>
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On Sun, 2011-11-20 at 14:14 +0800, Lan, Tianyu wrote:
> > OK. Thx.
> > But fsync is too slow. I try to find a way to sync a range of file. 
> > Are there any solutions to meet my purpose?

On Sun, 2011-11-20 at 08:23 +0200, Sasha Levin wrote:
> fdatasync() is as good as it'll get.
> 
> tbh, maybe we should just consider opening QCOW images with O_SYNC and
> just get it over with?

No, lets not do that. It's easier to improve the performance of correct
code that doesn't use O_SYNC.

			Pekka