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=-3.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS autolearn=no 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 E2203C2D0CE for ; Tue, 21 Jan 2020 11:12:40 +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 AB65A2253D for ; Tue, 21 Jan 2020 11:12:40 +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="ArnLmKYL" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AB65A2253D 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]:51874 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1itrSZ-00059P-CS for qemu-devel@archiver.kernel.org; Tue, 21 Jan 2020 06:12:39 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:41245) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1itrOh-0000Dt-95 for qemu-devel@nongnu.org; Tue, 21 Jan 2020 06:08:40 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1itrOd-0004WW-D7 for qemu-devel@nongnu.org; Tue, 21 Jan 2020 06:08:39 -0500 Received: from us-smtp-1.mimecast.com ([205.139.110.61]:36326 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 1itrOd-0004WN-9U for qemu-devel@nongnu.org; Tue, 21 Jan 2020 06:08:35 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1579604914; 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=zwIrFTaxN9a2qTlMPBKUIWO6noCAq3KUlr8hvzIoAS8=; b=ArnLmKYLjALbHmj9wdYdcwBF1ALNLbRW9VAsatAiogdvjakURzpguOH3JHIlvWg54XZOsr bI8N/OFPg1y5D4r0UkQAqpgXw56TKmcHMXejopEfHimNP/WQ+5L48k4ir4NJJUlS8lD5Hd 1Vp4Elskab6e0xc9tkvzSqKSPzpcLCQ= 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-402-Dp6j7vcnPbW7mLqkhJpJOA-1; Tue, 21 Jan 2020 06:08:31 -0500 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id C025D800D4C for ; Tue, 21 Jan 2020 11:08:30 +0000 (UTC) Received: from redhat.com (ovpn-116-23.ams2.redhat.com [10.36.116.23]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 54E7460BE0; Tue, 21 Jan 2020 11:08:30 +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: Tue, 21 Jan 2020 12:08:27 +0100 Message-ID: <87wo9lgj84.fsf@secure.laptop> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-MC-Unique: Dp6j7vcnPbW7mLqkhJpJOA-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: 205.139.110.61 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. Trying to redo this as something more reasonable. Problem that I was trying to do is being sure that we know in what state we are. Real migration states are: - NOT_STARTED: We haven't even started - SETUP: We have started with local stuff but haven't yet transmitted anything - ACTIVE: Migration is donig well, we are trasnmitting data - FINISHED: We have finished migration (COMPLETED/FAILED/CANCELLED/CANCELLI= NG) - COLO: Yet a completelly different can of worms To make things even more interesting, we export ->state, so code can do whatever they want with that variable. What do we need in a lot of places: - migration_is_running() (i.e. channel is still open). And we go left and right to be sure what is going on. >> @@ -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. As said, I will try to move that to inside migrate_set_state() thanks, Juan.