From: Stefan Hajnoczi <stefanha@gmail.com>
To: Christoph Hellwig <hch@lst.de>
Cc: kwolf@redhat.com,
"prerna@linux.vnet.ibm.com Anthony Liguori" <aliguori@us.ibm.com>,
qemu-devel@nongnu.org
Subject: [Qemu-devel] Re: [PATCH 1/4] block: clarify the meaning of BDRV_O_NOCACHE
Date: Wed, 16 Mar 2011 17:00:42 +0000 [thread overview]
Message-ID: <AANLkTim=+ELwL1pc=4ASb133qUEXt+-Dj0XZBA=GXj5S@mail.gmail.com> (raw)
In-Reply-To: <20110316140844.GA21877@lst.de>
On Wed, Mar 16, 2011 at 2:08 PM, Christoph Hellwig <hch@lst.de> wrote:
> On Wed, Mar 16, 2011 at 09:42:37AM +0000, Stefan Hajnoczi wrote:
>> - writethrough = ((flags & BDRV_O_CACHE_MASK) == 0);
>> + writethrough = ((flags & (BDRV_O_CACHE_WB | BDRV_O_NO_FLUSH)) == 0);
>
> or rather
>
> writethrough = ((flags & (BDRV_O_CACHE_WB) != );
>
> but yes, this code had sneaked in since my initial version.
My intention was that if we don't care about honoring flushes then we
might as well use Qcow2Cache. But yes, just checking for cache mode
is the clearest.
Stefan
next prev parent reply other threads:[~2011-03-16 17:00 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-03-15 14:10 [Qemu-devel] [PATCH, RFC 0/4] allow guest control of the volatile write cache Christoph Hellwig
2011-03-15 14:11 ` [Qemu-devel] [PATCH 1/4] block: clarify the meaning of BDRV_O_NOCACHE Christoph Hellwig
2011-03-16 9:42 ` [Qemu-devel] " Stefan Hajnoczi
2011-03-16 9:55 ` Kevin Wolf
2011-03-16 14:08 ` Christoph Hellwig
2011-03-16 17:00 ` Stefan Hajnoczi [this message]
2011-03-17 9:07 ` Kevin Wolf
2011-03-17 9:18 ` Stefan Hajnoczi
2011-03-15 14:11 ` [Qemu-devel] [PATCH 2/4] block: add a helper to change writeback mode on the fly Christoph Hellwig
2011-03-15 14:11 ` [Qemu-devel] [PATCH 3/4] ide: wire up setfeatures cache control Christoph Hellwig
2011-03-15 14:11 ` [Qemu-devel] [PATCH 4/4] virtio-blk: add runtime " Christoph Hellwig
2011-03-16 9:49 ` [Qemu-devel] Re: [PATCH 2/4] block: add a helper to change writeback mode on the fly Stefan Hajnoczi
2011-03-16 9:59 ` Kevin Wolf
2011-03-17 14:44 ` [Qemu-devel] " Daniel P. Berrange
2011-03-17 15:11 ` Kevin Wolf
2011-03-17 16:44 ` Stefan Hajnoczi
2011-03-19 8:28 ` Blue Swirl
2011-03-15 14:16 ` [Qemu-devel] [PATCH, RFC] virtio_blk: add cache control support Christoph Hellwig
2011-03-16 4:09 ` [Qemu-devel] " Rusty Russell
2011-03-16 14:09 ` Christoph Hellwig
2011-03-17 5:06 ` Rusty Russell
2011-03-17 14:21 ` Christoph Hellwig
2011-03-24 0:11 ` Rusty Russell
2011-03-24 3:11 ` Anthony Liguori
2011-03-24 3:05 ` Anthony Liguori
2011-03-24 9:54 ` Christian Borntraeger
2011-03-25 5:08 ` Rusty Russell
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