[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] callout to *file in bdrv_co_get_block_status
From: |
Paolo Bonzini |
Subject: |
Re: [Qemu-devel] callout to *file in bdrv_co_get_block_status |
Date: |
Fri, 31 Mar 2017 12:20:10 +0200 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.7.0 |
On 31/03/2017 09:55, Peter Lieven wrote:
>>> Would it be an idea to introduce an inverse flag live BDRV_BLOCK_NOT_ZERO
>>> for cases where we know that there is really DATA and thus can avoid the
>>> second callout?
>> How would you know that a block is nonzero?
> I would trust the metadata. At least for VMDK and QCOW2v3.
> Bad idea?
The metadata only tells you that a block is zero, not that it's nonzero.
What you are suggesting is really the same as removing the recursion.
However, I still haven't understood clearly if it's a QEMU or tmpfs bug;
if it's a tmpfs bug your suggestion would not fix tmpfs slowness on raw
images.
Paolo
- Re: [Qemu-devel] callout to *file in bdrv_co_get_block_status, (continued)
- Re: [Qemu-devel] callout to *file in bdrv_co_get_block_status, Peter Lieven, 2017/03/20
- Re: [Qemu-devel] callout to *file in bdrv_co_get_block_status, Peter Lieven, 2017/03/20
- Re: [Qemu-devel] callout to *file in bdrv_co_get_block_status, Paolo Bonzini, 2017/03/20
- Re: [Qemu-devel] callout to *file in bdrv_co_get_block_status, Peter Lieven, 2017/03/20
- Re: [Qemu-devel] callout to *file in bdrv_co_get_block_status, Paolo Bonzini, 2017/03/20
- Re: [Qemu-devel] callout to *file in bdrv_co_get_block_status, Peter Lieven, 2017/03/20
- Re: [Qemu-devel] callout to *file in bdrv_co_get_block_status, Paolo Bonzini, 2017/03/20
- Re: [Qemu-devel] callout to *file in bdrv_co_get_block_status, Peter Lieven, 2017/03/27
- Re: [Qemu-devel] callout to *file in bdrv_co_get_block_status, Paolo Bonzini, 2017/03/27
- Re: [Qemu-devel] callout to *file in bdrv_co_get_block_status, Peter Lieven, 2017/03/31
- Re: [Qemu-devel] callout to *file in bdrv_co_get_block_status,
Paolo Bonzini <=
- Re: [Qemu-devel] callout to *file in bdrv_co_get_block_status, Fam Zheng, 2017/03/17
- Re: [Qemu-devel] callout to *file in bdrv_co_get_block_status, Paolo Bonzini, 2017/03/17
- Re: [Qemu-devel] callout to *file in bdrv_co_get_block_status, Peter Lieven, 2017/03/18