From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58482) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Ws6Kc-00062S-8k for qemu-devel@nongnu.org; Wed, 04 Jun 2014 04:14:05 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Ws6KV-0001W6-Hh for qemu-devel@nongnu.org; Wed, 04 Jun 2014 04:13:58 -0400 Received: from mail-pb0-f53.google.com ([209.85.160.53]:59300) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Ws6KV-0001Vv-Cy for qemu-devel@nongnu.org; Wed, 04 Jun 2014 04:13:51 -0400 Received: by mail-pb0-f53.google.com with SMTP id md12so6664215pbc.40 for ; Wed, 04 Jun 2014 01:13:50 -0700 (PDT) Message-ID: <538ED539.3060806@ozlabs.ru> Date: Wed, 04 Jun 2014 18:13:45 +1000 From: Alexey Kardashevskiy MIME-Version: 1.0 References: <1395892646-30283-1-git-send-email-aik@ozlabs.ru> <87siq4rp5b.fsf@blackfin.pond.sub.org> <53494FD0.8020009@ozlabs.ru> <53604D73.1040905@ozlabs.ru> <87tx94pj49.fsf@elfo.mitica> In-Reply-To: <87tx94pj49.fsf@elfo.mitica> Content-Type: text/plain; charset=KOI8-R Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] migration: Increase default max_downtime from 30ms to 300ms List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: quintela@redhat.com Cc: Paolo Bonzini , Markus Armbruster , "Dr . David Alan Gilbert" , qemu-devel@nongnu.org On 05/05/2014 09:20 PM, Juan Quintela wrote: > Alexey Kardashevskiy wrote: >> On 04/13/2014 12:38 AM, Alexey Kardashevskiy wrote: >>> On 03/27/2014 08:01 PM, Markus Armbruster wrote: >>>> Adding Juan. >>> >>> >>> Ping? > > Patch is OK for me. Who else needs to be ok to get this in upstream? :) Thanks! > As sender says, with guests doing anything/bigger than 1GB RAM is > basically implosible to get into the 30ms downtime. > > Later, Juan. > >> >> >> Ping? >> >> >>> >>>> >>>> Alexey Kardashevskiy writes: >>>> >>>>> The existing timeout is 30ms which on 100MB/s (1Gbit) gives us >>>>> 3MB/s rate maximum. If we put some load on the guest, it is easy to >>>>> get page dirtying rate too big so live migration will never complete. >>>>> In the case of libvirt that means that the guest will be stopped >>>>> anyway after a timeout specified in the "virsh migrate" command and >>>>> this normally generates even bigger delay. >>>>> >>>>> This changes max_downtime to 300ms which seems to be more >>>>> reasonable value. >>>>> >>>>> Signed-off-by: Alexey Kardashevskiy >>>>> --- >>>>> migration.c | 2 +- >>>>> 1 file changed, 1 insertion(+), 1 deletion(-) >>>>> >>>>> diff --git a/migration.c b/migration.c >>>>> index e0e24d4..02bbce9 100644 >>>>> --- a/migration.c >>>>> +++ b/migration.c >>>>> @@ -144,7 +144,7 @@ void process_incoming_migration(QEMUFile *f) >>>>> * the choice of nanoseconds is because it is the maximum resolution that >>>>> * get_clock() can achieve. It is an internal measure. All user-visible >>>>> * units must be in seconds */ >>>>> -static uint64_t max_downtime = 30000000; >>>>> +static uint64_t max_downtime = 300000000; >>>>> >>>>> uint64_t migrate_max_downtime(void) >>>>> { >>> >>> -- Alexey