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[Qemu-devel] [PATCH] qcow2: improve I/O performance with cache=off
From: |
Laurent Vivier |
Subject: |
[Qemu-devel] [PATCH] qcow2: improve I/O performance with cache=off |
Date: |
Fri, 20 Jun 2008 16:38:00 +0200 |
Hi,
this patch improves qcow2 I/O performance when used with cache=off.
It modifies qcow_aio_[read|write]_cb() to read as many clusters as
possible per bdrv_aio_[read|write]().
I've made some tests with dbench:
WITHOUT PATCH WITH PATCH
ide, cache=off,snapshot=off 20.8494 MB/sec 24.0711 MB/sec
ide, cache=off,snapshot=on 20.9349 MB/sec 24.5031 MB/sec
scsi,cache=off,snapshot=off 21.0264 MB/sec 24.6119 MB/sec
scsi,cache=off,snapshot=on 21.4184 MB/sec 24.6739 MB/sec
The gain is approximately 15%.
Regards,
Laurent
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qcow2.patch
Description: Text Data
- [Qemu-devel] [PATCH] qcow2: improve I/O performance with cache=off,
Laurent Vivier <=