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 50891C76186 for ; Tue, 23 Jul 2019 17:24:10 +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 20F6122543 for ; Tue, 23 Jul 2019 17:24:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 20F6122543 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]:46258 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hpyWH-0004ez-1T for qemu-devel@archiver.kernel.org; Tue, 23 Jul 2019 13:24:09 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:51243) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hpyW7-0004Do-Dt for qemu-devel@nongnu.org; Tue, 23 Jul 2019 13:24:00 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hpyW6-0007NH-Au for qemu-devel@nongnu.org; Tue, 23 Jul 2019 13:23:59 -0400 Received: from mx1.redhat.com ([209.132.183.28]:45340) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hpyW6-0007Mm-5L for qemu-devel@nongnu.org; Tue, 23 Jul 2019 13:23:58 -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 0B70030860A7; Tue, 23 Jul 2019 17:23:57 +0000 (UTC) Received: from work-vm (ovpn-117-202.ams2.redhat.com [10.36.117.202]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 2E87D5D9C5; Tue, 23 Jul 2019 17:23:55 +0000 (UTC) Date: Tue, 23 Jul 2019 18:23:53 +0100 From: "Dr. David Alan Gilbert" To: Wei Yang Message-ID: <20190723172353.GO2719@work-vm> References: <20190720223939.11327-1-richardw.yang@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190720223939.11327-1-richardw.yang@linux.intel.com> User-Agent: Mutt/1.12.0 (2019-05-25) 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 [10.5.110.44]); Tue, 23 Jul 2019 17:23:57 +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] migration/postcopy: use mis->bh instead of allocating a QEMUBH 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, quintela@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" * Wei Yang (richardw.yang@linux.intel.com) wrote: > For migration incoming side, it either quit in precopy or postcopy. It > is save to use the mis->bh for both instead of allocating a dedicated ^^^^ 'safe' not 'save' > QEMUBH for postcopy. > > Signed-off-by: Wei Yang Yes, I think that's OK; it's a little subtle. Once postcopy is in 'run' then the main incoming code will exit before running it's bh, so you're right that it's free for us to use. Reviewed-by: Dr. David Alan Gilbert > --- > migration/savevm.c | 17 ++++------------- > 1 file changed, 4 insertions(+), 13 deletions(-) > > diff --git a/migration/savevm.c b/migration/savevm.c > index 25fe7ea05a..0105068579 100644 > --- a/migration/savevm.c > +++ b/migration/savevm.c > @@ -1856,16 +1856,10 @@ static int loadvm_postcopy_handle_listen(MigrationIncomingState *mis) > return 0; > } > > - > -typedef struct { > - QEMUBH *bh; > -} HandleRunBhData; > - > static void loadvm_postcopy_handle_run_bh(void *opaque) > { > Error *local_err = NULL; > - HandleRunBhData *data = opaque; > - MigrationIncomingState *mis = migration_incoming_get_current(); > + MigrationIncomingState *mis = opaque; > > /* TODO we should move all of this lot into postcopy_ram.c or a shared code > * in migration.c > @@ -1897,8 +1891,7 @@ static void loadvm_postcopy_handle_run_bh(void *opaque) > runstate_set(RUN_STATE_PAUSED); > } > > - qemu_bh_delete(data->bh); > - g_free(data); > + qemu_bh_delete(mis->bh); > } > > /* After all discards we can start running and asking for pages */ > @@ -1906,7 +1899,6 @@ static int loadvm_postcopy_handle_run(MigrationIncomingState *mis) > { > PostcopyState old_ps = POSTCOPY_INCOMING_LISTENING; > PostcopyState ps = postcopy_state_set(POSTCOPY_INCOMING_RUNNING, &old_ps); > - HandleRunBhData *data; > > trace_loadvm_postcopy_handle_run(); > if (ps != old_ps) { > @@ -1914,9 +1906,8 @@ static int loadvm_postcopy_handle_run(MigrationIncomingState *mis) > return -1; > } > > - data = g_new(HandleRunBhData, 1); > - data->bh = qemu_bh_new(loadvm_postcopy_handle_run_bh, data); > - qemu_bh_schedule(data->bh); > + mis->bh = qemu_bh_new(loadvm_postcopy_handle_run_bh, mis); > + qemu_bh_schedule(mis->bh); > > /* We need to finish reading the stream from the package > * and also stop reading anything more from the stream that loaded the > -- > 2.17.1 > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK