From: Paolo Bonzini <pbonzini@redhat.com>
To: Peter Lieven <pl@kamp.de>
Cc: Kevin Wolf <kwolf@redhat.com>,
Stefan Hajnoczi <stefanha@redhat.com>,
qemu-devel <qemu-devel@nongnu.org>,
ronnie sahlberg <ronniesahlberg@gmail.com>
Subject: Re: [Qemu-devel] [PATCH 4/4] qemu-img: conditionally discard target on convert
Date: Wed, 17 Jul 2013 19:04:01 +0200 [thread overview]
Message-ID: <51E6CE81.6000400@redhat.com> (raw)
In-Reply-To: <7C1EEB41-E2B3-4186-9188-379F02E76FF9@kamp.de>
Il 17/07/2013 19:02, Peter Lieven ha scritto:
> For Disks we always use read/write16 so i think we Should also use writesame16. Or not?
Yes.
Remember you can still use UNMAP if LBPRZ=0.
Paolo
> Von meinem iPhone gesendet
>
> Am 17.07.2013 um 18:31 schrieb ronnie sahlberg <ronniesahlberg@gmail.com>:
>
>> On Wed, Jul 17, 2013 at 9:27 AM, Paolo Bonzini <pbonzini@redhat.com> wrote:
>>> Il 17/07/2013 17:54, ronnie sahlberg ha scritto:
>>>> I think it is reasonable to assume that IF LBPRZ==1 and IF it is an
>>>> "optimal unmap request" then the blocks will become unmapped and they
>>>> will read back as 0.
>>>
>>> Yes, but it is not reasonable to assume that bdrv_discard will only
>>> receive "optimal" requests. Thus, using WRITE SAME for LBPRZ=1, and not
>>> exposing LBPRZ=1 if LBPWS=0 (may also use LBPWS10 depending on the
>>> capacity), is the safer thing to do.
>>>
>>> Paolo
>>
>> ACK.
>>
>> WRITESAME10/16 with UNMAP flag set is probably best.
next prev parent reply other threads:[~2013-07-17 17:04 UTC|newest]
Thread overview: 72+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-07-15 10:49 [Qemu-devel] [PATCH 0/4] qemu-img: conditionally discard target on convert Peter Lieven
2013-07-15 10:49 ` [Qemu-devel] [PATCH 1/4] block: add discard_zeroes and max_unmap to BlockDriverInfo Peter Lieven
2013-07-15 10:49 ` [Qemu-devel] [PATCH 2/4] iscsi: add .bdrv_get_info Peter Lieven
2013-07-15 10:49 ` [Qemu-devel] [PATCH 3/4] block/raw: " Peter Lieven
2013-07-19 5:12 ` Stefan Hajnoczi
2013-07-15 10:49 ` [Qemu-devel] [PATCH 4/4] qemu-img: conditionally discard target on convert Peter Lieven
2013-07-17 8:46 ` Kevin Wolf
2013-07-17 9:58 ` Paolo Bonzini
2013-07-17 10:21 ` Peter Lieven
2013-07-17 10:27 ` Kevin Wolf
2013-07-17 10:31 ` Peter Lieven
2013-07-17 10:47 ` Paolo Bonzini
2013-07-17 14:19 ` Peter Lieven
2013-07-17 10:45 ` Paolo Bonzini
2013-07-17 14:21 ` Peter Lieven
2013-07-17 14:26 ` Paolo Bonzini
2013-07-17 10:25 ` Kevin Wolf
2013-07-17 15:54 ` ronnie sahlberg
2013-07-17 16:27 ` Paolo Bonzini
2013-07-17 16:31 ` ronnie sahlberg
2013-07-17 17:02 ` Peter Lieven
2013-07-17 17:04 ` Paolo Bonzini [this message]
2013-07-17 17:48 ` Peter Lieven
2013-07-17 20:00 ` Paolo Bonzini
2013-07-18 9:23 ` Kevin Wolf
2013-07-18 10:24 ` Paolo Bonzini
2013-07-18 10:42 ` Kevin Wolf
2013-07-18 10:44 ` Peter Lieven
2013-07-18 10:56 ` Paolo Bonzini
2013-07-18 11:04 ` Peter Lieven
2013-07-18 12:31 ` Paolo Bonzini
2013-07-18 13:29 ` Peter Lieven
2013-07-18 13:52 ` Paolo Bonzini
2013-07-18 14:09 ` Peter Lieven
2013-07-18 14:20 ` Paolo Bonzini
2013-07-18 14:32 ` Peter Lieven
2013-07-18 14:35 ` Paolo Bonzini
2013-07-18 18:43 ` Peter Lieven
2013-07-18 18:54 ` ronnie sahlberg
2013-07-18 19:28 ` Peter Lieven
2013-07-19 5:58 ` Paolo Bonzini
2013-07-19 6:08 ` Peter Lieven
2013-07-19 13:25 ` ronnie sahlberg
2013-07-19 13:49 ` Peter Lieven
2013-07-19 14:00 ` ronnie sahlberg
2013-07-19 14:02 ` Peter Lieven
2013-07-19 13:58 ` ronnie sahlberg
2013-07-18 13:55 ` ronnie sahlberg
2013-07-18 14:14 ` Paolo Bonzini
2013-09-12 8:52 ` Peter Lieven
2013-09-12 8:55 ` Paolo Bonzini
2013-09-12 9:03 ` Peter Lieven
2013-07-17 17:09 ` ronnie sahlberg
2013-07-18 9:21 ` Kevin Wolf
2013-07-17 10:22 ` Peter Lieven
2013-07-16 10:55 ` [Qemu-devel] [PATCH 0/4] " Paolo Bonzini
2013-07-16 11:18 ` Peter Lieven
2013-07-16 11:27 ` Paolo Bonzini
2013-07-16 11:40 ` Peter Lieven
2013-07-16 11:55 ` Paolo Bonzini
2013-07-17 10:23 ` Peter Lieven
2013-07-17 10:28 ` Paolo Bonzini
2013-07-17 10:40 ` Peter Lieven
2013-07-17 10:50 ` Paolo Bonzini
2013-07-17 14:18 ` Peter Lieven
2013-07-17 14:26 ` Paolo Bonzini
2013-07-17 14:46 ` Peter Lieven
2013-07-17 14:53 ` Paolo Bonzini
2013-07-17 15:12 ` Kevin Wolf
2013-07-17 16:53 ` Peter Lieven
2013-07-17 17:01 ` Peter Lieven
2013-07-19 5:13 ` Stefan Hajnoczi
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