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 72160C433FF for ; Wed, 14 Aug 2019 14:59:05 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 483D52063F for ; Wed, 14 Aug 2019 14:59:05 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 483D52063F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:33152 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1hxujw-0005r0-Ha for qemu-devel@archiver.kernel.org; Wed, 14 Aug 2019 10:59:04 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:36493) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1hxuj6-0005FO-R8 for qemu-devel@nongnu.org; Wed, 14 Aug 2019 10:58:14 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hxuiy-0007jJ-FU for qemu-devel@nongnu.org; Wed, 14 Aug 2019 10:58:12 -0400 Received: from mx1.redhat.com ([209.132.183.28]:43168) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hxuiy-0007ix-7j for qemu-devel@nongnu.org; Wed, 14 Aug 2019 10:58:04 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 57CD2308C386 for ; Wed, 14 Aug 2019 14:58:03 +0000 (UTC) Received: from work-vm (ovpn-117-212.ams2.redhat.com [10.36.117.212]) by smtp.corp.redhat.com (Postfix) with ESMTPS id A0B4C88B2C; Wed, 14 Aug 2019 14:58:02 +0000 (UTC) Date: Wed, 14 Aug 2019 15:58:00 +0100 From: "Dr. David Alan Gilbert" To: Juan Quintela Message-ID: <20190814145800.GM2920@work-vm> References: <20190814020218.1868-1-quintela@redhat.com> <20190814020218.1868-4-quintela@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190814020218.1868-4-quintela@redhat.com> User-Agent: Mutt/1.12.1 (2019-06-15) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.48]); Wed, 14 Aug 2019 14:58:03 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: Re: [Qemu-devel] [PATCH 3/6] migration: Make sure that all multifd channels have been created X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" * Juan Quintela (quintela@redhat.com) wrote: > If we start the migration before all have been created, we have to > handle the case that one channel still don't exist. This way it is > easier. > > Signed-off-by: Juan Quintela > --- > migration/ram.c | 14 ++++++++++++++ > migration/trace-events | 1 + > 2 files changed, 15 insertions(+) > > diff --git a/migration/ram.c b/migration/ram.c > index 4bdd201a4e..4a6ae677a9 100644 > --- a/migration/ram.c > +++ b/migration/ram.c > @@ -663,6 +663,8 @@ typedef struct { > uint64_t num_pages; > /* syncs main thread and channels */ > QemuSemaphore sem_sync; > + /* thread has started and setup is done */ > + QemuSemaphore started; > } MultiFDSendParams; > > typedef struct { > @@ -1039,6 +1041,7 @@ void multifd_save_cleanup(void) > qemu_mutex_destroy(&p->mutex); > qemu_sem_destroy(&p->sem); > qemu_sem_destroy(&p->sem_sync); > + qemu_sem_destroy(&p->started); > g_free(p->name); > p->name = NULL; > multifd_pages_clear(p->pages); > @@ -1113,6 +1116,8 @@ static void *multifd_send_thread(void *opaque) > /* initial packet */ > p->num_packets = 1; > > + qemu_sem_post(&p->started); > + > while (true) { > qemu_sem_wait(&p->sem); > qemu_mutex_lock(&p->mutex); > @@ -1229,6 +1234,7 @@ int multifd_save_setup(void) > qemu_mutex_init(&p->mutex); > qemu_sem_init(&p->sem, 0); > qemu_sem_init(&p->sem_sync, 0); > + qemu_sem_init(&p->started, 0); > p->quit = false; > p->pending_job = 0; > p->id = i; > @@ -3486,6 +3492,14 @@ static int ram_save_setup(QEMUFile *f, void *opaque) > ram_control_before_iterate(f, RAM_CONTROL_SETUP); > ram_control_after_iterate(f, RAM_CONTROL_SETUP); > > + /* We want to wait for all threads to have started before doing > + * anything else */ > + for (int i = 0; i < migrate_multifd_channels(); i++) { > + MultiFDSendParams *p = &multifd_send_state->params[i]; > + > + qemu_sem_wait(&p->started); > + trace_multifd_send_thread_started(p->id); > + } What happens if there's an error during startup and either we cancel or the migration fails and we try and cleanup - how do we get out of this loop? Dave > multifd_send_sync_main(); > qemu_put_be64(f, RAM_SAVE_FLAG_EOS); > qemu_fflush(f); > diff --git a/migration/trace-events b/migration/trace-events > index 886ce70ca0..dd13a5c4b1 100644 > --- a/migration/trace-events > +++ b/migration/trace-events > @@ -95,6 +95,7 @@ multifd_send_sync_main_wait(uint8_t id) "channel %d" > multifd_send_terminate_threads(bool error) "error %d" > multifd_send_thread_end(uint8_t id, uint64_t packets, uint64_t pages) "channel %d packets %" PRIu64 " pages %" PRIu64 > multifd_send_thread_start(uint8_t id) "%d" > +multifd_send_thread_started(uint8_t id) "channel %d" > ram_discard_range(const char *rbname, uint64_t start, size_t len) "%s: start: %" PRIx64 " %zx" > ram_load_loop(const char *rbname, uint64_t addr, int flags, void *host) "%s: addr: 0x%" PRIx64 " flags: 0x%x host: %p" > ram_load_postcopy_loop(uint64_t addr, int flags) "@%" PRIx64 " %x" > -- > 2.21.0 > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK