From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56892) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WhHD8-0003eD-H2 for qemu-devel@nongnu.org; Mon, 05 May 2014 07:37:35 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WhHD0-0005LF-UZ for qemu-devel@nongnu.org; Mon, 05 May 2014 07:37:30 -0400 Received: from mx1.redhat.com ([209.132.183.28]:3755) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WhHD0-0005KV-MJ for qemu-devel@nongnu.org; Mon, 05 May 2014 07:37:22 -0400 From: Juan Quintela In-Reply-To: <53604D73.1040905@ozlabs.ru> (Alexey Kardashevskiy's message of "Wed, 30 Apr 2014 11:10:11 +1000") References: <1395892646-30283-1-git-send-email-aik@ozlabs.ru> <87siq4rp5b.fsf@blackfin.pond.sub.org> <53494FD0.8020009@ozlabs.ru> <53604D73.1040905@ozlabs.ru> Date: Mon, 05 May 2014 13:20:22 +0200 Message-ID: <87tx94pj49.fsf@elfo.mitica> MIME-Version: 1.0 Content-Type: text/plain Subject: Re: [Qemu-devel] [PATCH] migration: Increase default max_downtime from 30ms to 300ms Reply-To: quintela@redhat.com List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexey Kardashevskiy Cc: Paolo Bonzini , Markus Armbruster , "Dr . David Alan Gilbert" , qemu-devel@nongnu.org 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. 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) >>>> { >> >>