From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CEF9AC7618B for ; Wed, 24 Jul 2019 10:58:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A9A3922387 for ; Wed, 24 Jul 2019 10:58:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726681AbfGXK6l (ORCPT ); Wed, 24 Jul 2019 06:58:41 -0400 Received: from mx1.redhat.com ([209.132.183.28]:55052 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726070AbfGXK6k (ORCPT ); Wed, 24 Jul 2019 06:58:40 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 7A89F8F02B; Wed, 24 Jul 2019 10:58:40 +0000 (UTC) Received: from work-vm (ovpn-117-166.ams2.redhat.com [10.36.117.166]) by smtp.corp.redhat.com (Postfix) with ESMTPS id A078160A9F; Wed, 24 Jul 2019 10:58:38 +0000 (UTC) Date: Wed, 24 Jul 2019 11:58:36 +0100 From: "Dr. David Alan Gilbert" To: Juan Quintela Cc: qemu-devel@nongnu.org, Paolo Bonzini , Laurent Vivier , kvm@vger.kernel.org, Thomas Huth , Richard Henderson , Ivan Ren , Ivan Ren Subject: Re: [PATCH 2/4] migration: fix migrate_cancel leads live_migration thread hung forever Message-ID: <20190724105836.GB2717@work-vm> References: <20190724095523.1527-1-quintela@redhat.com> <20190724095523.1527-3-quintela@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190724095523.1527-3-quintela@redhat.com> User-Agent: Mutt/1.12.0 (2019-05-25) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Wed, 24 Jul 2019 10:58:40 +0000 (UTC) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org * Juan Quintela (quintela@redhat.com) wrote: > From: Ivan Ren > > When we 'migrate_cancel' a multifd migration, live_migration thread may > hung forever at some points, because of multifd_send_thread has already > exit for socket error: > 1. multifd_send_pages may hung at qemu_sem_wait(&multifd_send_state-> > channels_ready) > 2. multifd_send_sync_main my hung at qemu_sem_wait(&multifd_send_state-> > sem_sync) > > Signed-off-by: Ivan Ren > Message-Id: <1561468699-9819-3-git-send-email-ivanren@tencent.com> > Reviewed-by: Juan Quintela > Signed-off-by: Juan Quintela Reviewed-by: Dr. David Alan Gilbert > > --- > > Remove spurious not needed bits > --- > migration/ram.c | 16 ++++++++++++++-- > 1 file changed, 14 insertions(+), 2 deletions(-) > > diff --git a/migration/ram.c b/migration/ram.c > index 52a2d498e4..87bb7da8e2 100644 > --- a/migration/ram.c > +++ b/migration/ram.c > @@ -1097,7 +1097,8 @@ static void *multifd_send_thread(void *opaque) > { > MultiFDSendParams *p = opaque; > Error *local_err = NULL; > - int ret; > + int ret = 0; > + uint32_t flags = 0; > > trace_multifd_send_thread_start(p->id); > rcu_register_thread(); > @@ -1115,7 +1116,7 @@ static void *multifd_send_thread(void *opaque) > if (p->pending_job) { > uint32_t used = p->pages->used; > uint64_t packet_num = p->packet_num; > - uint32_t flags = p->flags; > + flags = p->flags; > > p->next_packet_size = used * qemu_target_page_size(); > multifd_send_fill_packet(p); > @@ -1164,6 +1165,17 @@ out: > multifd_send_terminate_threads(local_err); > } > > + /* > + * Error happen, I will exit, but I can't just leave, tell > + * who pay attention to me. > + */ > + if (ret != 0) { > + if (flags & MULTIFD_FLAG_SYNC) { > + qemu_sem_post(&multifd_send_state->sem_sync); > + } > + qemu_sem_post(&multifd_send_state->channels_ready); > + } > + > qemu_mutex_lock(&p->mutex); > p->running = false; > qemu_mutex_unlock(&p->mutex); > -- > 2.21.0 > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK