From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:41328) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1erELT-0005m2-Hg for qemu-devel@nongnu.org; Wed, 28 Feb 2018 21:53:24 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1erELO-00079K-Ld for qemu-devel@nongnu.org; Wed, 28 Feb 2018 21:53:23 -0500 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:52110 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 1erELO-00078d-HQ for qemu-devel@nongnu.org; Wed, 28 Feb 2018 21:53:18 -0500 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 181B840FB646 for ; Thu, 1 Mar 2018 02:53:18 +0000 (UTC) Date: Thu, 1 Mar 2018 10:53:12 +0800 From: Peter Xu Message-ID: <20180301025312.GN27381@xz-mi> References: <20180228050633.7410-1-peterx@redhat.com> <20180228050633.7410-5-peterx@redhat.com> <20180228174349.GJ2981@work-vm> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20180228174349.GJ2981@work-vm> Subject: Re: [Qemu-devel] [PATCH 04/14] migration: let incoming side use thread context List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Dr. David Alan Gilbert" Cc: qemu-devel@nongnu.org, Paolo Bonzini , "Daniel P . Berrange" , Juan Quintela , Markus Armbruster , =?utf-8?Q?Marc-Andr=C3=A9?= Lureau , Stefan Hajnoczi , Laurent Vivier On Wed, Feb 28, 2018 at 05:43:50PM +0000, Dr. David Alan Gilbert wrote: > * Peter Xu (peterx@redhat.com) wrote: > > The old incoming migration is running in main thread and default > > gcontext. With the new qio_channel_add_watch_full() we can now let it > > run in the thread's own gcontext (if there is one). > > > > Currently this patch does nothing alone. But when any of the incoming > > migration is run in another iothread (e.g., the upcoming migrate-recover > > command), this patch will bind the incoming logic to the iothread > > instead of the main thread (which may already get page faulted and > > hanged). > > Does this make any difference to the Postcopy listener thread, which > takes over reading from the main thread once in postcopy mode? > (See savevm.c:postcopy_ram_listen_thread). It should not. It should only affect when use sends a "migrate-recover" with "run-oob=true". The rest should be the same as before. And since the postcopy ram load thread is a standalone thread with its own initial thread stack (so it's not really in a gmainloop), I can hardly tell how that can be affected since it'll always use its own thread stack. Or, have I missed anything? -- Peter Xu