From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53996) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eWf8F-00046m-QQ for qemu-devel@nongnu.org; Wed, 03 Jan 2018 04:14:47 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eWf8C-0008S3-GU for qemu-devel@nongnu.org; Wed, 03 Jan 2018 04:14:43 -0500 Received: from mx1.redhat.com ([209.132.183.28]:58792) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1eWf8C-0008Ps-A5 for qemu-devel@nongnu.org; Wed, 03 Jan 2018 04:14:40 -0500 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 6C8C66A7CB for ; Wed, 3 Jan 2018 09:14:39 +0000 (UTC) From: Juan Quintela In-Reply-To: <20180103054043.25719-9-peterx@redhat.com> (Peter Xu's message of "Wed, 3 Jan 2018 13:40:40 +0800") References: <20180103054043.25719-1-peterx@redhat.com> <20180103054043.25719-9-peterx@redhat.com> Reply-To: quintela@redhat.com Date: Wed, 03 Jan 2018 10:14:33 +0100 Message-ID: <87fu7n2tja.fsf@secure.laptop> MIME-Version: 1.0 Content-Type: text/plain Subject: Re: [Qemu-devel] [PATCH 08/11] migration: use switch at the end of migration List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Xu Cc: qemu-devel@nongnu.org, Laurent Vivier , "Dr . David Alan Gilbert" Peter Xu wrote: > It converts the old if clauses into switch, explicitly mentions the > possible migration states. The old nested "if"s are not clear on what > we do on different states. > > Signed-off-by: Peter Xu > --- > migration/migration.c | 32 +++++++++++++++++++++----------- > 1 file changed, 21 insertions(+), 11 deletions(-) > > diff --git a/migration/migration.c b/migration/migration.c > index acef54748b..bfcba24caa 100644 > --- a/migration/migration.c > +++ b/migration/migration.c > @@ -2296,19 +2296,23 @@ static void *migration_thread(void *opaque) > cpu_throttle_stop(); > > qemu_mutex_lock_iothread(); > - if (s->state == MIGRATION_STATUS_COMPLETED) { > + switch (s->state) { > + case MIGRATION_STATUS_COMPLETED: > migration_calculate_complete(s); > runstate_set(RUN_STATE_POSTMIGRATE); > - } else { > - if (s->state == MIGRATION_STATUS_ACTIVE) { > - assert(migrate_colo_enabled()); > - migrate_start_colo_process(s); > - /* > - * Fixme: we will run VM in COLO no matter its old running state. > - * After exited COLO, we will keep running. > - */ > - s->old_vm_running = true; > - } > + break; > + > + case MIGRATION_STATUS_ACTIVE: > + assert(migrate_colo_enabled()); > + migrate_start_colo_process(s); I think this line is wrong, you still have to proctect it with the if (migrate_cole_enabled). Rest of cleanup, is something that I like. Later, Juan. > + /* > + * Fixme: we will run VM in COLO no matter its old running state. > + * After exited COLO, we will keep running. > + */ > + s->old_vm_running = true; > + /* Fallthrough */ Actually, I don't like Fallthrought on C, but well, problem is C O:-) > + case MIGRATION_STATUS_FAILED: > + case MIGRATION_STATUS_CANCELLED: > if (s->old_vm_running) { > vm_start(); > } else { > @@ -2316,6 +2320,12 @@ static void *migration_thread(void *opaque) > runstate_set(RUN_STATE_POSTMIGRATE); > } > } > + break; > + > + default: > + /* Should not reach here, but if so, forgive the VM. */ > + error_report("%s: Unknown ending state %d", __func__, s->state); > + break; > } > qemu_bh_schedule(s->cleanup_bh); > qemu_mutex_unlock_iothread();