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Date: Mon, 2 Feb 2015 20:00:05 +0300
From: "Denis V. Lunev" <den@openvz.org>
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Subject: Re: [Qemu-devel] [PATCH] block: change default for discard and
 write zeroes to INT_MAX
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To: Kevin Wolf <kwolf@redhat.com>
Cc: Peter Lieven <pl@kamp.de>, qemu-devel@nongnu.org

On 02/02/15 19:45, Kevin Wolf wrote:
> Am 02.02.2015 um 17:25 hat Denis V. Lunev geschrieben:
>> On 02/02/15 19:13, Kevin Wolf wrote:
>>> Am 02.02.2015 um 15:48 hat Peter Lieven geschrieben:
>>>> do not trim requests if the driver does not supply a limit
>>>> through BlockLimits. For write zeroes we still keep a limit
>>>> for the unsupported path to avoid allocating a big bounce buffer.
>>>>
>>>> Suggested-by: Kevin Wolf <kwolf@redhat.com>
>>>> Suggested-by: Denis V. Lunev <den@openvz.org>
>>>> Signed-off-by: Peter Lieven <pl@kamp.de>
>>> Thanks, applied to the block branch (and removed 'block/raw-posix: set
>>> max_write_zeroes to INT_MAX for regular files' from the queue).
>>>
>>> Kevin
>> double checked the code.
>>
>> There are 2 things to patch for discard, write_zeroes is OK for me.
>> Sorry, for not paying attention for discard branch :(
> Good catch, thanks!
>
> But shouldn't we use the actual limits instead of INT_MAX, i.e. SIZE_MAX
> for gluster and UINT32_MAX for nbd?
>
> Kevin
You are absolutely correct for NBD case but I do not get the
point about SIZE_MAX for gluster. There is no such definition
in their git at git://github.com/gluster/glusterfs nor in
public API headers in Ubuntu :(

Regards,
     Den