From: Kevin Wolf <kwolf@redhat.com>
To: Liu Yuan <namei.unix@gmail.com>
Cc: Stefan Hajnoczi <stefanha@gmail.com>,
qemu-devel@nongnu.org,
MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>,
Paolo Bonzini <pbonzini@redhat.com>
Subject: Re: [Qemu-devel] [PATCH] sheepdog: implement direct write semantics
Date: Tue, 08 Jan 2013 11:00:34 +0100 [thread overview]
Message-ID: <50EBEE42.7010407@redhat.com> (raw)
In-Reply-To: <50EBEAD2.6070608@gmail.com>
Am 08.01.2013 10:45, schrieb Liu Yuan:
> On 01/08/2013 05:40 PM, Stefan Hajnoczi wrote:
>> Otherwise use sheepdog writeback and let QEMU block.c decide when to
>> flush. Never use sheepdog writethrough because it's redundant here.
>
> I don't get it. What do you mean by 'redundant'? If we use virtio &
> sheepdog block driver, how can we specify writethrough mode for Sheepdog
> cache? Here 'writethrough' means use a pure read cache, which doesn't
> need flush at all.
A writethrough cache is equivalent to a write-back cache where each
write is followed by a flush. qemu makes sure to send these flushes, so
there is no need use Sheepdog's writethrough mode.
Kevin
next prev parent reply other threads:[~2013-01-08 10:27 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-12-19 18:29 [Qemu-devel] [PATCH] sheepdog: implement direct write semantics Liu Yuan
2012-12-25 7:47 ` MORITA Kazutaka
2012-12-25 8:26 ` Liu Yuan
2012-12-25 8:45 ` Liu Yuan
2013-01-03 13:43 ` Liu Yuan
2013-01-04 16:38 ` Stefan Hajnoczi
2013-01-05 4:40 ` Liu Yuan
2013-01-05 5:29 ` Liu Yuan
2013-01-05 7:56 ` Liu Yuan
2013-01-07 12:31 ` Stefan Hajnoczi
2013-01-08 5:28 ` Liu Yuan
2013-01-07 13:23 ` Kevin Wolf
2013-01-08 5:42 ` Liu Yuan
2013-01-08 9:40 ` Stefan Hajnoczi
2013-01-08 9:45 ` Liu Yuan
2013-01-08 10:00 ` Kevin Wolf [this message]
2013-01-08 10:39 ` Liu Yuan
2013-01-08 10:51 ` Kevin Wolf
2013-01-08 11:08 ` Liu Yuan
2013-01-08 11:19 ` Kevin Wolf
2013-01-08 11:35 ` Liu Yuan
2013-01-08 12:12 ` Kevin Wolf
2013-01-08 13:18 ` Liu Yuan
2013-01-08 13:23 ` Liu Yuan
2013-01-09 10:25 ` Paolo Bonzini
2013-01-09 10:36 ` Liu Yuan
2013-01-09 10:40 ` Paolo Bonzini
2013-01-09 10:46 ` Liu Yuan
2013-01-09 10:58 ` Liu Yuan
2013-01-09 11:10 ` Paolo Bonzini
2013-01-09 12:07 ` Liu Yuan
2013-01-09 12:10 ` Liu Yuan
2013-01-09 12:16 ` Liu Yuan
2013-01-09 12:42 ` Kevin Wolf
2013-01-09 13:04 ` Liu Yuan
2013-01-09 15:10 ` Paolo Bonzini
2013-01-10 5:38 ` Liu Yuan
2013-01-11 7:52 ` MORITA Kazutaka
2013-01-11 8:07 ` Liu Yuan
2013-01-11 9:00 ` Paolo Bonzini
2013-01-11 9:04 ` Liu Yuan
2013-01-11 9:34 ` Paolo Bonzini
2013-01-11 9:38 ` Liu Yuan
2013-01-11 9:40 ` Paolo Bonzini
2013-01-11 9:32 ` Kevin Wolf
2013-01-10 15:25 ` Jamie Lokier
2013-01-10 15:31 ` Paolo Bonzini
2013-01-10 17:22 ` Jamie Lokier
2013-01-09 11:10 ` Kevin Wolf
2013-01-09 10:23 ` Paolo Bonzini
2013-01-10 15:12 ` Jamie Lokier
2013-01-10 15:21 ` Kevin Wolf
2013-01-10 8:03 ` [Qemu-devel] [PATCH v2] " Liu Yuan
2013-01-10 9:04 ` Stefan Hajnoczi
2013-01-11 7:35 ` MORITA Kazutaka
2013-01-11 9:23 ` Kevin Wolf
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