From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:44867) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fEGE4-0004UY-5S for qemu-devel@nongnu.org; Thu, 03 May 2018 11:32:57 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fEGE0-0003mq-7z for qemu-devel@nongnu.org; Thu, 03 May 2018 11:32:56 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:52114 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fEGE0-0003mU-3L for qemu-devel@nongnu.org; Thu, 03 May 2018 11:32:52 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 4F43A406C743 for ; Thu, 3 May 2018 15:32:48 +0000 (UTC) Date: Thu, 3 May 2018 16:32:41 +0100 From: "Dr. David Alan Gilbert" Message-ID: <20180503153240.GK2660@work-vm> References: <20180425112723.1111-1-quintela@redhat.com> <87sh7jy0gc.fsf@secure.mitica> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87sh7jy0gc.fsf@secure.mitica> Subject: Re: [Qemu-devel] [PATCH v12 00/21] Multifd List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Juan Quintela Cc: qemu-devel@nongnu.org, lvivier@redhat.com, peterx@redhat.com * Juan Quintela (quintela@redhat.com) wrote: > Juan Quintela wrote: > > Hi > > > > > > [v12] > > > > Big news, it is not RFC anymore, it works reliabely for me. > > > > Changes: > > - Locknig changed completely (several times) > > - We now send all pages through the channels. In a 2GB guest with 1 disk and a network card, the amount of data send for RAM was 80KB. > > - This is not optimized yet, but it shouws clear improvements over precopy. testing over localhost networking I can guet: > > - 2 VCPUs guest > > - 2GB RAM > > - runn stress --vm 4 --vm 500GB (i.e. dirtying 2GB or RAM each second) > > > > - Total time: precopy ~50seconds, multifd around 11seconds > > - Bandwidth usage is around 273MB/s vs 71MB/s on the same hardware > > > > This is very preleminary testing, will send more numbers when I got them. But looks promissing. > > > > Things that will be improved later: > > - Initial synchronization is too slow (around 1s) > > - We synchronize all threads after each RAM section, we can move to only > > synchronize them after we have done a bitmap syncrhronization > > - We can improve bitmap walking (but that is independent of multifd) > > I forgot to put there that on the last 4 patches, I have not been able > to split them in a way that: > - is logical for review > - works for multifd tests in all versions > > So, I ended trynig to get the "logical" viewe, and it works after the > last patch. Why is that? > - Before I am able to transmit data, I need to be able to > end/synchronize the different channels > - To finish channels in case of error, I just close the channels > But I can't opet then yet. > > I have to think if I can come with a simpler way to split it, but you > can also consider that the last 3-4 patches are a single one. I think most of the last few can be flattened into earlier patches; I'd prefer it rather than having patches that add stuff and then they get reworked/removed later. I don't think it matters that the order of the last few doesn't work until the end; since it didn't work at the beginning, it doesn't matter until the end of the series. Dave > Later, Juan. -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK