From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49157) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1edi97-0002Ku-7j for qemu-devel@nongnu.org; Mon, 22 Jan 2018 14:52:46 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1edi94-0007vr-4p for qemu-devel@nongnu.org; Mon, 22 Jan 2018 14:52:45 -0500 Received: from mx1.redhat.com ([209.132.183.28]:54548) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1edi93-0007vO-Tx for qemu-devel@nongnu.org; Mon, 22 Jan 2018 14:52:42 -0500 Date: Mon, 22 Jan 2018 19:52:21 +0000 From: "Dr. David Alan Gilbert" Message-ID: <20180122195221.GC2628@work-vm> References: <87h8rg2jdh.fsf@secure.laptop> <016e04bd-3ee3-dffc-943f-394c8583c886@samsung.com> <96f66b1f-2248-04ed-aabb-0cac1342b0cc@samsung.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <96f66b1f-2248-04ed-aabb-0cac1342b0cc@samsung.com> Subject: Re: [Qemu-devel] [PULL 00/27] Migration pull List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexey Perevalov Cc: Peter Maydell , Juan Quintela , Philippe =?iso-8859-1?Q?Mathieu-Daud=E9?= , Peter Xu , Alex =?iso-8859-1?Q?Benn=E9e?= , Laurent Vivier , QEMU Developers * Alexey Perevalov (a.perevalov@samsung.com) wrote: > On 01/22/2018 07:26 PM, Peter Maydell wrote: > > On 22 January 2018 at 16:25, Alexey Perevalov wrote: > > > I want to keep 64bit atomic operations in migration. > > Sorry, you can't -- some 32 bit CPUs simply do not provide these > > operations. You need to rework your design to not require this. > I would like to ask David, > how do you think is it normal to use just one half of now_ms (int64_t), one > half > of 64 bit value should represent 1200 hours and probably it's enough to keep > time > difference. Yes you could use an offset (start of migration?) - if the postcopy phase is taking more than that long we're probably in trouble. But remember your '0' value is special. Dave > > > > thanks > > -- PMM > > > > > > > > -- > Best regards, > Alexey Perevalov -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK