From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38735) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dskYG-0008Hs-7d for qemu-devel@nongnu.org; Fri, 15 Sep 2017 02:56:37 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dskYF-0002j1-EJ for qemu-devel@nongnu.org; Fri, 15 Sep 2017 02:56:36 -0400 Date: Fri, 15 Sep 2017 14:56:27 +0800 From: Peter Xu Message-ID: <20170915065627.GQ3617@pxdev.xzpeter.org> References: <20170915054404.19914-1-famz@redhat.com> <20170915054404.19914-2-famz@redhat.com> <20170915064132.GP3617@pxdev.xzpeter.org> <20170915064907.GD17199@lemon> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20170915064907.GD17199@lemon> Subject: Re: [Qemu-devel] [PATCH 1/3] migration: Allow ram_save_cleanup to be called with empty state List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Fam Zheng Cc: qemu-devel@nongnu.org, "Dr. David Alan Gilbert" , Juan Quintela , qemu-stable@nongnu.org On Fri, Sep 15, 2017 at 02:49:07PM +0800, Fam Zheng wrote: > On Fri, 09/15 14:41, Peter Xu wrote: > > On Fri, Sep 15, 2017 at 01:44:02PM +0800, Fam Zheng wrote: > > > So that we can do cleanup unconditionally at the end of main(). > > > > > > Signed-off-by: Fam Zheng > > > --- > > > migration/ram.c | 3 +++ > > > 1 file changed, 3 insertions(+) > > > > > > diff --git a/migration/ram.c b/migration/ram.c > > > index e18b3e2d4f..37e6a71241 100644 > > > --- a/migration/ram.c > > > +++ b/migration/ram.c > > > @@ -1365,6 +1365,9 @@ static void ram_save_cleanup(void *opaque) > > > RAMState **rsp = opaque; > > > RAMBlock *block; > > > > > > + if (!rsp || !*rsp) { > > > + return; > > > + } > > > /* caller have hold iothread lock or is in a bh, so there is > > > * no writing race against this migration_bitmap > > > */ > > > -- > > > 2.13.5 > > > > > > > Instead of take special care on RAM, how about check in > > migrate_fd_cancel(), and return directly if migration_is_idle()? > > This is not from migrate_fd_cancel(), but from qemu_savevm_state_cleanup(), so > that doesn't work. Yeh I see the point. But my logic still stands - we don't need to cleanup anything if the migration is not really there. I'm thinking whether we can put qemu_savevm_state_cleanup() into migrate_fd_cancel() in some way, though I am still not 100% sure on the colo part. Anyway, I feel like a bit confusing we have two cleanup functions. -- Peter Xu