From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40570) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YYwBm-0001M9-PJ for qemu-devel@nongnu.org; Fri, 20 Mar 2015 08:38:11 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YYwBk-00009W-3J for qemu-devel@nongnu.org; Fri, 20 Mar 2015 08:38:10 -0400 Received: from mx1.redhat.com ([209.132.183.28]:45885) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YYwBj-00009E-Tn for qemu-devel@nongnu.org; Fri, 20 Mar 2015 08:38:08 -0400 Date: Fri, 20 Mar 2015 12:37:59 +0000 From: "Dr. David Alan Gilbert" Message-ID: <20150320123759.GE2468@work-vm> References: <1424883128-9841-1-git-send-email-dgilbert@redhat.com> <1424883128-9841-21-git-send-email-dgilbert@redhat.com> <20150313010058.GZ11973@voom.redhat.com> <20150313101953.GA2486@work-vm> <20150316061840.GE5741@voom.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150316061840.GE5741@voom.redhat.com> Subject: Re: [Qemu-devel] [PATCH v5 20/45] Modify savevm handlers for postcopy List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: David Gibson Cc: aarcange@redhat.com, yamahata@private.email.ne.jp, quintela@redhat.com, qemu-devel@nongnu.org, amit.shah@redhat.com, pbonzini@redhat.com, yanghy@cn.fujitsu.com * David Gibson (david@gibson.dropbear.id.au) wrote: > On Fri, Mar 13, 2015 at 10:19:54AM +0000, Dr. David Alan Gilbert wrote: > > * David Gibson (david@gibson.dropbear.id.au) wrote: > > > On Wed, Feb 25, 2015 at 04:51:43PM +0000, Dr. David Alan Gilbert (git) wrote: > > > > From: "Dr. David Alan Gilbert" > > > > > > > > Modify save_live_pending to return separate postcopiable and > > > > non-postcopiable counts. > > > > > > > > Add 'can_postcopy' to allow a device to state if it can postcopy > > > > > > What's the purpose of the can_postcopy callback? There are no callers > > > in this patch - is it still necessary with the change to > > > save_live_pending? > > > > The patch 'qemu_savevm_state_complete: Postcopy changes' uses > > it in qemu_savevm_state_postcopy_complete and qemu_savevm_state_complete > > to decide which devices must be completed at that point. > > Couldn't they check for non-zero postcopiable state from > save_live_pending instead? That would be a bit weird. At the moment for each device we call the: save_live_setup method (from qemu_savevm_state_begin) 0...multiple times we call: save_live_pending save_live_iterate and then we always call save_live_complete To my mind we have to call save_live_complete for any device that we've called save_live_setup on (maybe it allocated something in _setup that it clears up in _complete). save_live_pending could perfectly well return 0 remaining at the end of the migrate for our device, and thus if we used that then we wouldn't call save_live_complete. Dave > > -- > David Gibson | I'll have my music baroque, and my code > david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ > | _way_ _around_! > http://www.ozlabs.org/~dgibson -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK