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Re: [Qemu-devel] [PATCH v12 0/6] qcow2, raw: add preallocation=full and
From: |
Richard W.M. Jones |
Subject: |
Re: [Qemu-devel] [PATCH v12 0/6] qcow2, raw: add preallocation=full and preallocation=falloc |
Date: |
Mon, 25 Aug 2014 14:44:52 +0100 |
User-agent: |
Mutt/1.5.20 (2009-12-10) |
On Mon, Aug 25, 2014 at 01:18:30PM +0800, Hu Tao wrote:
> What if user cares about time(writing zeroes or non-zeroes is
> time-consuming) and wants falloc only sometimes? I think this is the
> main difference between preallocation=falloc and preallocation=full.
Also posix_fallocate in glibc falls back to writing zeroes when the
kernel/VFS doesn't support a true fallocate. So I'm afraid your patch
5/6 has a slow path, at least on common Linux distros.
Rich.
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- Re: [Qemu-devel] [PATCH v12 0/6] qcow2, raw: add preallocation=full and preallocation=falloc, (continued)
- Re: [Qemu-devel] [PATCH v12 0/6] qcow2, raw: add preallocation=full and preallocation=falloc, Kevin Wolf, 2014/08/22
- Re: [Qemu-devel] [PATCH v12 0/6] qcow2, raw: add preallocation=full and preallocation=falloc, Richard W.M. Jones, 2014/08/22
- Re: [Qemu-devel] [PATCH v12 0/6] qcow2, raw: add preallocation=full and preallocation=falloc, Daniel P. Berrange, 2014/08/22
- Re: [Qemu-devel] [PATCH v12 0/6] qcow2, raw: add preallocation=full and preallocation=falloc, Kevin Wolf, 2014/08/22
- Re: [Qemu-devel] [PATCH v12 0/6] qcow2, raw: add preallocation=full and preallocation=falloc, Richard W.M. Jones, 2014/08/22
- Re: [Qemu-devel] [PATCH v12 0/6] qcow2, raw: add preallocation=full and preallocation=falloc, Richard W.M. Jones, 2014/08/22
- Re: [Qemu-devel] [PATCH v12 0/6] qcow2, raw: add preallocation=full and preallocation=falloc, Kevin Wolf, 2014/08/22
- Re: [Qemu-devel] [PATCH v12 0/6] qcow2, raw: add preallocation=full and preallocation=falloc, Richard W.M. Jones, 2014/08/22
- Re: [Qemu-devel] [PATCH v12 0/6] qcow2, raw: add preallocation=full and preallocation=falloc, Hu Tao, 2014/08/25
- Re: [Qemu-devel] [PATCH v12 0/6] qcow2, raw: add preallocation=full and preallocation=falloc, Richard W.M. Jones, 2014/08/25
- Re: [Qemu-devel] [PATCH v12 0/6] qcow2, raw: add preallocation=full and preallocation=falloc,
Richard W.M. Jones <=
- Re: [Qemu-devel] [PATCH v12 0/6] qcow2, raw: add preallocation=full and preallocation=falloc, Hu Tao, 2014/08/26