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From: "Denis V. Lunev" <den@openvz.org>
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Date: Fri, 25 Sep 2015 13:05:00 +0300
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Subject: Re: [Qemu-devel] [PATCH 1/2] migration: bitmap_set is unnecessary
 as bitmap_new uses g_try_malloc0
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To: Wen Congyang <wency@cn.fujitsu.com>
Cc: Amit Shah <amit.shah@redhat.com>, Igor Redko <redkoi@virtuozzo.com>, Juan Quintela <quintela@redhat.com>, qemu-devel@nongnu.org, Anna Melekhova <annam@virtuozzo.com>

On 09/25/2015 12:37 PM, Wen Congyang wrote:
> On 09/25/2015 05:31 PM, Denis V. Lunev wrote:
>> On 09/25/2015 12:24 PM, Wen Congyang wrote:
>>> On 09/25/2015 05:09 PM, Denis V. Lunev wrote:
>>>> we can omit calling of bitmap_set in migration_bitmap_extend and
>>>> ram_save_setup just after bitmap_new, which properly zeroes memory
>>>> inside.
>>> This patch is wrong. bitmap_set() is set all bits of the memory to 1,
>>> not 0.
>>>
>> OK, then I'll replace g_try_malloc0 with g_try_malloc in the next patch to avoid
>> double memset
> No, bitmap_new() is called in many places. Some caller needs zero memory, and
> some caller doesn't need...
>

you are correct with your proposal with double allocation for the next 
patch.
With a specific function like I have did in v2 g_try_malloc0 can be
replaced.

Anyway, I am fine with your proposal, this is not a (very) big deal. 
EINPROGRESS

Den