From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45795) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1f6hQA-0008Lw-Dt for qemu-devel@nongnu.org; Thu, 12 Apr 2018 14:58:11 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1f6hQ5-0004tq-TV for qemu-devel@nongnu.org; Thu, 12 Apr 2018 14:58:10 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:36582 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 1f6hQ5-0004tU-OP for qemu-devel@nongnu.org; Thu, 12 Apr 2018 14:58:05 -0400 Date: Thu, 12 Apr 2018 19:58:02 +0100 From: "Dr. David Alan Gilbert" Message-ID: <20180412185801.GK2704@work-vm> References: <1523089594-1422-1-git-send-email-lidongchen@tencent.com> <1523089594-1422-5-git-send-email-lidongchen@tencent.com> <20180411164357.GH2667@work-vm> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Subject: Re: [Qemu-devel] [PATCH 4/5] migration: fix qemu carsh when RDMA live migration List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: 858585 jemmy Cc: Juan Quintela , qemu-devel , adido@mellanox.com, licq@mellanox.com, Lidong Chen * 858585 jemmy (jemmy858585@gmail.com) wrote: > On Thu, Apr 12, 2018 at 12:43 AM, Dr. David Alan Gilbert > wrote: > > * Lidong Chen (jemmy858585@gmail.com) wrote: > >> After postcopy, the destination qemu work in the dedicated > >> thread, so only invoke yield_until_fd_readable before postcopy > >> migration. > > > > The subject line needs to be more discriptive: > > migration: Stop rdma yielding during incoming postcopy > > > > I think. > > (Also please check the subject spellings) > > > >> Signed-off-by: Lidong Chen > >> --- > >> migration/rdma.c | 4 +++- > >> 1 file changed, 3 insertions(+), 1 deletion(-) > >> > >> diff --git a/migration/rdma.c b/migration/rdma.c > >> index 53773c7..81be482 100644 > >> --- a/migration/rdma.c > >> +++ b/migration/rdma.c > >> @@ -1489,11 +1489,13 @@ static int qemu_rdma_wait_comp_channel(RDMAContext *rdma) > >> * Coroutine doesn't start until migration_fd_process_incoming() > >> * so don't yield unless we know we're running inside of a coroutine. > >> */ > >> - if (rdma->migration_started_on_destination) { > >> + if (rdma->migration_started_on_destination && > >> + migration_incoming_get_current()->state == MIGRATION_STATUS_ACTIVE) { > > > > OK, that's a bit delicate; watch if it ever gets called in a failure > > case or similar - and also wathc out if we make more use of the status > > on the destination, but otherwise, and with a fix for the subject; > > How about use migration_incoming_get_current()->have_listen_thread? That's supposed to be pretty internal to the postcopy code, so I prefer the status check. Dave > if (rdma->migration_started_on_destination && > migration_incoming_get_current()->have_listen_thread == false) { > yield_until_fd_readable(rdma->comp_channel->fd); > } > > > > > > > Reviewed-by: Dr. David Alan Gilbert > > > >> yield_until_fd_readable(rdma->comp_channel->fd); > >> } else { > >> /* This is the source side, we're in a separate thread > >> * or destination prior to migration_fd_process_incoming() > >> + * after postcopy, the destination also in a seprate thread. > >> * we can't yield; so we have to poll the fd. > >> * But we need to be able to handle 'cancel' or an error > >> * without hanging forever. > >> -- > >> 1.8.3.1 > >> > > -- > > Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK