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Re: [Qemu-devel] [PATCH 0/4] qcow2: Improve cluster refcount update
From: |
Kevin Wolf |
Subject: |
Re: [Qemu-devel] [PATCH 0/4] qcow2: Improve cluster refcount update |
Date: |
Fri, 07 Nov 2008 09:31:30 +0100 |
User-agent: |
Thunderbird 2.0.0.17 (X11/20080922) |
Anthony Liguori schrieb:
> Laurent Vivier wrote:
>> This series of patches improves qcow2 performance with O_DIRECT
>> when the qcow2 file is empty and we begin to fill it.
>>
>
> I really dislike this series and any future series that does similar
> things. The real problem is that non-aligned accesses are so slow, but
> there's no reason that they must be so slow. It's because we're doing
> synchronous IO operations instead of using posix-aio like we should.
> That's the real problem. Just doing a memory copy to an aligned buffer
> is not going to cause that much performance delay.
Even if you don't like the alignment part, patches 1 and 2 are still
useful, IMHO.
Kevin
- [Qemu-devel] [PATCH 0/4] qcow2: Improve cluster refcount update, Laurent Vivier, 2008/11/06
- Re: [Qemu-devel] [PATCH 0/4] qcow2: Improve cluster refcount update, Anthony Liguori, 2008/11/06
- Re: [Qemu-devel] [PATCH 0/4] qcow2: Improve cluster refcount update,
Kevin Wolf <=
- Re: [Qemu-devel] [PATCH 0/4] qcow2: Improve cluster refcount update, Laurent Vivier, 2008/11/07
- Re: [Qemu-devel] [PATCH 0/4] qcow2: Improve cluster refcount update, Anthony Liguori, 2008/11/07
- Re: [Qemu-devel] [PATCH 0/4] qcow2: Improve cluster refcount update, Laurent Vivier, 2008/11/07
- Re: [Qemu-devel] [PATCH 0/4] qcow2: Improve cluster refcount update, Anthony Liguori, 2008/11/07
- Re: [Qemu-devel] [PATCH 0/4] qcow2: Improve cluster refcount update, Laurent Vivier, 2008/11/07
- Re: [Qemu-devel] [PATCH 0/4] qcow2: Improve cluster refcount update, Avi Kivity, 2008/11/09
- Re: [Qemu-devel] [PATCH 0/4] qcow2: Improve cluster refcount update, Anthony Liguori, 2008/11/09
- Re: [Qemu-devel] [PATCH 0/4] qcow2: Improve cluster refcount update, Andreas Färber, 2008/11/10
- Re: [Qemu-devel] [PATCH 0/4] qcow2: Improve cluster refcount update, Anthony Liguori, 2008/11/10