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=-6.6 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 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 002EDC33CB6 for ; Fri, 17 Jan 2020 18:36:42 +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 C998B2082F for ; Fri, 17 Jan 2020 18:36:41 +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="erS7hEzF" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C998B2082F 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]:33404 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1isWTw-0002GH-9e for qemu-devel@archiver.kernel.org; Fri, 17 Jan 2020 13:36:32 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:34257) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1isWT4-0001BO-3M for qemu-devel@nongnu.org; Fri, 17 Jan 2020 13:35:42 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1isWSx-0005iL-OF for qemu-devel@nongnu.org; Fri, 17 Jan 2020 13:35:36 -0500 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:53874 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1isWSx-0005ho-Ai for qemu-devel@nongnu.org; Fri, 17 Jan 2020 13:35:31 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1579286130; h=from:from:reply-to: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=tst/jx3I9FtPMCaVUBWMFd6eyo1esdQoo87pkOTPS/I=; b=erS7hEzFYCcBNsvqk0+vjAo484ewLtyXS+2JPFacb+MXd1UIvn4mwXrWUNekP9QeltK5P5 Gcl87W7dhA5hEGQukwi15iTvWnJscHMKfrdis8LE9wfOlqkWwEQJ+RK04RqqoiE1OjkUEG kdH4lFymbr+ByVSW/QRcpymzGEZrkRg= 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-393-WltaX3SlO66XpJdqh3sm9w-1; Fri, 17 Jan 2020 13:35:29 -0500 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 151A314E8 for ; Fri, 17 Jan 2020 18:35:28 +0000 (UTC) Received: from redhat.com (ovpn-116-71.ams2.redhat.com [10.36.116.71]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 85B8C1BC6D; Fri, 17 Jan 2020 18:35:27 +0000 (UTC) From: Juan Quintela To: "Dr. David Alan Gilbert" Subject: Re: [PATCH v3 2/5] migration: Create MigrationState active field In-Reply-To: <20200117162612.GN3209@work-vm> (David Alan Gilbert's message of "Fri, 17 Jan 2020 16:26:12 +0000") References: <20200116154616.11569-1-quintela@redhat.com> <20200116154616.11569-3-quintela@redhat.com> <20200117162612.GN3209@work-vm> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.3 (gnu/linux) Date: Fri, 17 Jan 2020 19:35:25 +0100 Message-ID: <87k15q2aoi.fsf@secure.laptop> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-MC-Unique: WltaX3SlO66XpJdqh3sm9w-1 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 207.211.31.81 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: , Reply-To: quintela@redhat.com 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" "Dr. David Alan Gilbert" wrote: > * 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. My plan was to go the other way around. We need to use the state with atomics, I wanted a single way of deciding if we are/or not in the middle of a migration. Just now it is too confusing on my opinion. >> --- >> 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. Ok. Thanks, Juan.