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=-8.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, 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 78785C33CB1 for ; Fri, 17 Jan 2020 16:27:12 +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 4521E2072E for ; Fri, 17 Jan 2020 16:27:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="JRxv7baw" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4521E2072E 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]:59876 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1isUSl-0005pd-Av for qemu-devel@archiver.kernel.org; Fri, 17 Jan 2020 11:27:11 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:45352) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1isUS0-0005GY-UO for qemu-devel@nongnu.org; Fri, 17 Jan 2020 11:26:29 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1isURw-0005KW-4N for qemu-devel@nongnu.org; Fri, 17 Jan 2020 11:26:24 -0500 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:59174 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1isURw-0005JO-00 for qemu-devel@nongnu.org; Fri, 17 Jan 2020 11:26:20 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1579278378; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=o1SCoHGlwxSj2pWHzUDgSzNc0S7n42hRqUof4YgbeH8=; b=JRxv7baw9TUkvBLcoOyQnYjbe1iXJEpOABLK/taH6coFknKNH5qn5KOnBlof4pLSi4Y5RA 6PnPWzXrO8A7/+1WFHk3Rm0S7DtQRfZgibJyJeDVA3AuiZ1H23PGbdOfKwkCbFO3VVVtFD oaS714oCeNqxKyK9f+bT2dXB3ToUzqY= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-202-CMyulCCvObi7XEME9zswrg-1; Fri, 17 Jan 2020 11:26:17 -0500 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 794F1107ACCC for ; Fri, 17 Jan 2020 16:26:16 +0000 (UTC) Received: from work-vm (unknown [10.36.118.51]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 33A5281207; Fri, 17 Jan 2020 16:26:15 +0000 (UTC) Date: Fri, 17 Jan 2020 16:26:12 +0000 From: "Dr. David Alan Gilbert" To: Juan Quintela Subject: Re: [PATCH v3 2/5] migration: Create MigrationState active field Message-ID: <20200117162612.GN3209@work-vm> References: <20200116154616.11569-1-quintela@redhat.com> <20200116154616.11569-3-quintela@redhat.com> MIME-Version: 1.0 In-Reply-To: <20200116154616.11569-3-quintela@redhat.com> User-Agent: Mutt/1.13.0 (2019-11-30) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-MC-Unique: CMyulCCvObi7XEME9zswrg-1 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Content-Disposition: inline X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 205.139.110.120 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: Laurent Vivier , Paolo Bonzini , Thomas Huth , 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: > Right now, there is no easy way to dectect if we have already > cancelled/finished/failed a migration. This field is setup to true > when we start a migration, and it is set to false as soon as we stop > it. >=20 > It fixes a real bug, in ram_save_iterate() we call functions that > wrote to the channel even if we know that migration has stopped for > any reason. This gives problems with multifd because we need to > synchronize various semoaphores that we don't want to take. >=20 > Signed-off-by: Juan Quintela Why can't you use migration_is_active() in the ram.c case? My preference would be just to stick with something derived from the state rather than tacking another state bit on. > --- > migration/migration.c | 5 +++++ > migration/migration.h | 5 +++++ > migration/ram.c | 2 +- > migration/savevm.c | 2 ++ > 4 files changed, 13 insertions(+), 1 deletion(-) >=20 > diff --git a/migration/migration.c b/migration/migration.c > index 990bff00c0..60bc8710b6 100644 > --- a/migration/migration.c > +++ b/migration/migration.c > @@ -1583,6 +1583,8 @@ static void migrate_fd_cancel(MigrationState *s) > QEMUFile *f =3D migrate_get_current()->to_dst_file; > trace_migrate_fd_cancel(); > =20 > + s->active =3D false; > + > if (s->rp_state.from_dst_file) { > /* shutdown the rp socket, so causing the rp thread to shutdown = */ > qemu_file_shutdown(s->rp_state.from_dst_file); > @@ -2834,6 +2836,7 @@ static void migration_completion(MigrationState *s) > } > =20 > if (!migrate_colo_enabled()) { > + s->active =3D false; > migrate_set_state(&s->state, current_active_state, > MIGRATION_STATUS_COMPLETED); You've not always got these two the same way around - i.e. do you change the state first or do you set the active state first? I think it needs to be consistent. > } > @@ -2859,6 +2862,7 @@ fail_invalidate: > } > =20 > fail: > + s->active =3D false; > migrate_set_state(&s->state, current_active_state, > MIGRATION_STATUS_FAILED); > } > @@ -3289,6 +3293,7 @@ static void *migration_thread(void *opaque) > } > =20 > qemu_savevm_state_setup(s->to_dst_file); > + s->active =3D true; > =20 > if (qemu_savevm_nr_failover_devices()) { > migrate_set_state(&s->state, MIGRATION_STATUS_SETUP, > diff --git a/migration/migration.h b/migration/migration.h > index aa9ff6f27b..e0386efe95 100644 > --- a/migration/migration.h > +++ b/migration/migration.h > @@ -169,6 +169,11 @@ struct MigrationState > =20 > int state; > =20 > + /* Is the migration channel still open. When migration finish, > + * gets an error or is cancelled this becomes false. > + */ > + > + bool active; > /* State related to return path */ > struct { > QEMUFile *from_dst_file; > diff --git a/migration/ram.c b/migration/ram.c > index 8f9f3bba5b..44ca56e1ea 100644 > --- a/migration/ram.c > +++ b/migration/ram.c > @@ -3521,7 +3521,7 @@ static int ram_save_iterate(QEMUFile *f, void *opaq= ue) > ram_control_after_iterate(f, RAM_CONTROL_ROUND); > =20 > out: > - if (ret >=3D 0) { > + if (ret >=3D 0 && migrate_get_current()->active) { > multifd_send_sync_main(rs); > qemu_put_be64(f, RAM_SAVE_FLAG_EOS); > qemu_fflush(f); > diff --git a/migration/savevm.c b/migration/savevm.c > index adfdca26ac..3efde5b3dd 100644 > --- a/migration/savevm.c > +++ b/migration/savevm.c > @@ -1550,6 +1550,7 @@ static int qemu_savevm_state(QEMUFile *f, Error **e= rrp) > qemu_mutex_unlock_iothread(); > qemu_savevm_state_header(f); > qemu_savevm_state_setup(f); > + ms->active =3D true; > qemu_mutex_lock_iothread(); > =20 > while (qemu_file_get_error(f) =3D=3D 0) { > @@ -1574,6 +1575,7 @@ static int qemu_savevm_state(QEMUFile *f, Error **e= rrp) > status =3D MIGRATION_STATUS_COMPLETED; > } > migrate_set_state(&ms->state, MIGRATION_STATUS_SETUP, status); > + ms->active =3D false; > =20 > /* f is outer parameter, it should not stay in global migration stat= e after > * this function finished */ > --=20 > 2.24.1 >=20 -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK