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Re: [Qemu-devel] Effect of qemu-img convert -m and -W options
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From: |
Richard W.M. Jones |
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Subject: |
Re: [Qemu-devel] Effect of qemu-img convert -m and -W options |
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Date: |
Thu, 16 Nov 2017 15:12:33 +0000 |
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User-agent: |
Mutt/1.5.20 (2009-12-10) |
On Thu, Nov 16, 2017 at 03:51:29PM +0100, Peter Lieven wrote:
> Afaik all writes to the same QCOW2 serialize because of the s->lock that
> is held during the write. So its not suprising that there is no benefit from
> mutliple threads as long as reading from the RAW file involves no delay.
> Which is likely due to readahead of the OS.
I guess this would explain it, thanks.
Rich.
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