From: Avi Kivity <avi@redhat.com>
To: Javier Guerra <javier@guerrag.com>
Cc: Christoph Hellwig <hch@lst.de>,
Matthew Tippett <tippettm@gmail.com>,
Dustin Kirkland <dustin.kirkland@gmail.com>,
Anthony Liguori <anthony@codemonkey.ws>, RW <kvm@tauceti.net>,
kvm@vger.kernel.org
Subject: Re: [PATCH] virtio-blk: fallback to draining the queue if barrier ops are not supported
Date: Thu, 15 Oct 2009 01:53:22 +0900 [thread overview]
Message-ID: <4AD60202.2000205@redhat.com> (raw)
In-Reply-To: <90eb1dc70910140746t3e787f00q3d6784b38c3bd802@mail.gmail.com>
On 10/14/2009 11:46 PM, Javier Guerra wrote:
> On Wed, Oct 14, 2009 at 7:03 AM, Avi Kivity<avi@redhat.com> wrote:
>
>> Early implementations of virtio devices did not support barrier operations,
>> but did commit the data to disk. In such cases, drain the queue to emulate
>> barrier operations.
>>
> would this help on the (i think common) situation with XFS on a
> virtio-enabled VM, using LVM-backed storage; where LVM just loses
> barriers.
>
No, it's a guest only patch. If LVM loses barriers, I don't think
anything can restore them.
--
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.
next prev parent reply other threads:[~2009-10-14 16:54 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-09-25 7:00 sync guest calls made async on host - SQLite performance RW
2009-09-27 11:37 ` Avi Kivity
2009-09-27 12:07 ` Matthew Tippett
2009-09-29 19:02 ` Anthony Liguori
2009-09-29 19:32 ` Matthew Tippett
2009-09-29 20:46 ` Dustin Kirkland
2009-09-29 20:51 ` Anthony Liguori
2009-10-07 14:15 ` Matthew Tippett
2009-10-07 16:53 ` Matthew Tippett
2009-10-07 18:59 ` Dustin Kirkland
2009-10-07 19:31 ` Matthew Tippett
2009-10-07 20:12 ` Avi Kivity
2009-10-07 21:01 ` Matthew Tippett
2009-10-09 6:05 ` Dustin Kirkland
[not found] ` <4ACE0196.9010904@gmail.com>
[not found] ` <d9c105ea0910082312n7218e1abhc69a2be660838e89@mail.gmail.com>
[not found] ` <f28b49ce0910090425p385636c3he6dfb7595927d7e4@mail.gmail.com>
2009-10-09 15:18 ` Dustin Kirkland
2009-10-09 19:06 ` Matthew Tippett
2009-10-11 9:16 ` Avi Kivity
2009-10-13 22:37 ` Christoph Hellwig
2009-10-14 11:03 ` Avi Kivity
2009-10-14 12:03 ` [PATCH] virtio-blk: fallback to draining the queue if barrier ops are not supported Avi Kivity
2009-10-14 14:46 ` Javier Guerra
2009-10-14 16:53 ` Avi Kivity [this message]
2009-10-14 15:38 ` Michael Tokarev
2009-10-14 15:46 ` Christoph Hellwig
2009-10-14 13:41 ` sync guest calls made async on host - SQLite performance Christoph Hellwig
2009-10-14 16:56 ` Avi Kivity
2009-10-14 17:02 ` Christoph Hellwig
2009-10-14 22:54 ` Anthony Liguori
2009-10-14 23:37 ` Avi Kivity
2009-10-15 12:17 ` Christoph Hellwig
2009-10-15 12:36 ` Christoph Hellwig
2009-10-19 5:56 ` Avi Kivity
2009-10-13 23:08 ` Anthony Liguori
2009-10-14 2:09 ` Matthew Tippett
2009-10-14 4:12 ` Dustin Kirkland
2009-10-14 11:32 ` Matthew Tippett
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