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Re: [Qemu-devel] [PATCH 0/4] qcow2: Improve cluster refcount update
From: |
Laurent Vivier |
Subject: |
Re: [Qemu-devel] [PATCH 0/4] qcow2: Improve cluster refcount update |
Date: |
Fri, 07 Nov 2008 16:01:03 +0100 |
Le vendredi 07 novembre 2008 à 07:59 -0600, Anthony Liguori a écrit :
> Laurent Vivier wrote:
> > BTW, patch #1 is a clean-up (no change, only code move) and patch #2
> > doesn't align buffer, but try to minimise syscall (it improves
> > performance with O_DSYNC too).
> >
> > Ignore patch #3 and #4 if you dislike them.
> >
>
> But how useful is #1 and #2 if the buffers aren't aligned and we're
> hitting the slow path?
In all cases #1 is totally useless as it is only cosmetic.
#2 improves performance without aligned buffers and with "cache" set to
default value.
I've installed ubuntu 8.04 desktop on an empty qcow2 file using qemu:
without patch: 16 minutes 54 seconds
with patch: 15 minutes 44 seconds
Regards,
Laurent
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- [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, 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 <=
- 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