[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] Regression: block: Add .bdrv_co_pwrite_zeroes()
From: |
Eric Blake |
Subject: |
Re: [Qemu-devel] Regression: block: Add .bdrv_co_pwrite_zeroes() |
Date: |
Mon, 4 Jul 2016 19:53:14 -0600 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 |
On 07/04/2016 07:49 AM, Peter Lieven wrote:
> Hi,
>
> the above commit:
>
> commit d05aa8bb4a8b6aa9a915ec5074fb12ae632d2323
> Author: Eric Blake <address@hidden>
> Date: Wed Jun 1 15:10:03 2016 -0600
>
> block: Add .bdrv_co_pwrite_zeroes()
>
> introduces a regression (at least for me).
>
> The Limits from the iSCSI Block Limits VPD have no requirement of being
> a power of two.
> We use Dell Equallogic iSCSI SANs for instance. They have an internal
> page size of 15MB. And
> they advertise this page size as max_ws_len, opt_transfer_len and
> opt_discard_alignment.
A non-power-of-2 max_ws_len shouldn't be a problem, but opt_transfer_len
and opt_discard_alignment not being a power of 2 impacts other code.
15MB is a rather odd page size.
>
> I think we cannot assert that that these alignments are a power of 2.
Perhaps that means we should just fix our code to round things down to
the nearest power of 2 (8MB) for the opt_transfer_len and
opt_discard_alignment values. Can you post a stack-trace of the actual
assertion you are hitting?
--
Eric Blake eblake redhat com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
signature.asc
Description: OpenPGP digital signature
- [Qemu-devel] Regression: block: Add .bdrv_co_pwrite_zeroes(), Peter Lieven, 2016/07/04
- Re: [Qemu-devel] Regression: block: Add .bdrv_co_pwrite_zeroes(),
Eric Blake <=
- Re: [Qemu-devel] Regression: block: Add .bdrv_co_pwrite_zeroes(), Paolo Bonzini, 2016/07/05
- Re: [Qemu-devel] Regression: block: Add .bdrv_co_pwrite_zeroes(), Peter Lieven, 2016/07/05
- Re: [Qemu-devel] Regression: block: Add .bdrv_co_pwrite_zeroes(), Eric Blake, 2016/07/05
- Re: [Qemu-devel] Regression: block: Add .bdrv_co_pwrite_zeroes(), Paolo Bonzini, 2016/07/05
- Re: [Qemu-devel] Regression: block: Add .bdrv_co_pwrite_zeroes(), Peter Lieven, 2016/07/15
- Re: [Qemu-devel] Regression: block: Add .bdrv_co_pwrite_zeroes(), Eric Blake, 2016/07/15
- Re: [Qemu-devel] Regression: block: Add .bdrv_co_pwrite_zeroes(), Peter Lieven, 2016/07/18