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From: Juan Quintela <quintela@redhat.com>
To: Chegu Vinod <chegu_vinod@hp.com>
Cc: qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [PATCH 00/18] Migration thread lite (20121029)
Date: Mon, 29 Oct 2012 18:33:21 +0100	[thread overview]
Message-ID: <87mwz5kwta.fsf@elfo.mitica> (raw)
In-Reply-To: <508EAFC5.9050803@hp.com> (Chegu Vinod's message of "Mon, 29 Oct 2012 09:33:09 -0700")

Chegu Vinod <chegu_vinod@hp.com> wrote:
> On 10/29/2012 9:21 AM, Vinod, Chegu wrote:
>> Date: Mon, 29 Oct 2012 15:11:25 +0100
>> From: Juan Quintela <quintela@redhat.com>
>> To: qemu-devel@nongnu.org
>> Cc: owasserm@redhat.com, mtosatti@redhat.com, avi@redhat.com,
>> 	pbonzini@redhat.com
>> Subject: [Qemu-devel] [PATCH 00/18] Migration thread lite (20121029)
>>
>> Hi
>>
>> After discussing with Anthony and Paolo, this is the minimal migration thread support that we can do for 1.3.
>>
>> - fixed all the comments (thanks eric, paolo and orit).
>> - buffered_file.c remains until 1.4.
>> - testing for vinod showed very nice results, that is why the bitmap
>>    handling optimizations remain.
>
> Hi Juan,
>
> Is there any value in calling the migration_bitmap_synch() routine in
> the ram_save_setup() . All the
> pages were marked as dirty to begin with...so can't we just assume
> that all pages need to be sent
> and proceed ?

I haven't investigated it fully, but if we don't do it, we end sending
each page twice.  As said that needs more investigation.

>
> migration_bitmap_synch () - still remains an expensive call. and the
> very first call to seems to be ~3x times
>  more expensive than the subsequent calls. For large guests (>128G
> guests) this is multiple seconds...and
> it freezes the OS instance.

Will try to implement the other optimizaton, but that is 1.4 material
:-(

Later, Juan.)

  reply	other threads:[~2012-10-29 17:33 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <4168C988EBDF2141B4E0B6475B6A73D101905D46@G6W2493.americas.hpqcorp.net>
2012-10-29 16:33 ` [Qemu-devel] [PATCH 00/18] Migration thread lite (20121029) Chegu Vinod
2012-10-29 17:33   ` Juan Quintela [this message]
2012-10-29 14:11 Juan Quintela

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