From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53833) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WiOUq-0002L0-1G for qemu-devel@nongnu.org; Thu, 08 May 2014 09:36:30 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WiOUj-0006cw-UF for qemu-devel@nongnu.org; Thu, 08 May 2014 09:36:23 -0400 Received: from mx1.redhat.com ([209.132.183.28]:30991) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WiOUj-0006cr-MR for qemu-devel@nongnu.org; Thu, 08 May 2014 09:36:17 -0400 Message-ID: <536B884D.6080504@redhat.com> Date: Thu, 08 May 2014 15:36:13 +0200 From: Paolo Bonzini MIME-Version: 1.0 References: <53693FA4.3000306@windriver.com> <5369D504.2070101@redhat.com> <536AB2EE.6010504@windriver.com> <20140508130231.GA24978@grmbl.mre> <536B8332.9070705@redhat.com> <20140508133052.GA25602@grmbl.mre> In-Reply-To: <20140508133052.GA25602@grmbl.mre> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] virtio-serial-pci very expensive during live migration List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Amit Shah Cc: Chris Friesen , qemu-devel@nongnu.org, armbru@redhat.com Il 08/05/2014 15:30, Amit Shah ha scritto: > On (Thu) 08 May 2014 [15:14:26], Paolo Bonzini wrote: >> Il 08/05/2014 15:02, Amit Shah ha scritto: >>>>> I tried the patch below. Unfortunately it seems to cause qemu to crash. >>> This doesn't remove the memory_region_transaction_begin() and >>> _commit() from memory_region_add_eventfd(), which will still be >>> called. >> >> That's correct, transactions can be nested. > > But each _commit() will add to the delay? No, only the outermost one. Paolo