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=-2.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_NEOMUTT 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 DE2A2ECDFD0 for ; Fri, 14 Sep 2018 09:39:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 91E5620853 for ; Fri, 14 Sep 2018 09:39:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 91E5620853 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=citrix.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728169AbeINOwl (ORCPT ); Fri, 14 Sep 2018 10:52:41 -0400 Received: from smtp03.citrix.com ([162.221.156.55]:27136 "EHLO SMTP03.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726776AbeINOwl (ORCPT ); Fri, 14 Sep 2018 10:52:41 -0400 X-IronPort-AV: E=Sophos;i="5.53,372,1531785600"; d="scan'208";a="65299678" Date: Fri, 14 Sep 2018 10:38:58 +0100 From: Wei Liu To: Juergen Gross CC: Dongli Zhang , , , , , , , , Subject: Re: [PATCH 6/6] drivers: enable xenwatch multithreading for xen-netback and xen-blkback driver Message-ID: <20180914093858.fwu6aqwwjbsdbbt4@zion.uk.xensource.com> References: <1536910456-13337-1-git-send-email-dongli.zhang@oracle.com> <1536910456-13337-7-git-send-email-dongli.zhang@oracle.com> <518d3ec9-0d2d-7f77-e750-3e1329f7e97b@suse.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <518d3ec9-0d2d-7f77-e750-3e1329f7e97b@suse.com> User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Sep 14, 2018 at 11:16:30AM +0200, Juergen Gross wrote: > On 14/09/18 09:34, Dongli Zhang wrote: > > This is the 6th patch of a (6-patch) patch set. > > > > As the 'use_mtwatch' for xen-netback and xen-blkback are set to true, > > probing any xenbus devices of those two drivers would create the per-domU > > xenwatch thread for the domid the new devices belong to, or increment the > > reference count of existing thread. > > > > Xenwatch multithreading might be enabled for more xen backend pv drivers in > > the future. > > > > Signed-off-by: Dongli Zhang > > --- > > drivers/block/xen-blkback/xenbus.c | 3 ++- > > drivers/net/xen-netback/xenbus.c | 1 + > > 2 files changed, 3 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c > > index a4bc74e..debbbd0 100644 > > --- a/drivers/block/xen-blkback/xenbus.c > > +++ b/drivers/block/xen-blkback/xenbus.c > > @@ -1108,7 +1108,8 @@ static struct xenbus_driver xen_blkbk_driver = { > > .ids = xen_blkbk_ids, > > .probe = xen_blkbk_probe, > > .remove = xen_blkbk_remove, > > - .otherend_changed = frontend_changed > > + .otherend_changed = frontend_changed, > > + .use_mtwatch = true, > > }; > > > > int xen_blkif_xenbus_init(void) > > diff --git a/drivers/net/xen-netback/xenbus.c b/drivers/net/xen-netback/xenbus.c > > index cd51492..63d46a7 100644 > > --- a/drivers/net/xen-netback/xenbus.c > > +++ b/drivers/net/xen-netback/xenbus.c > > @@ -1203,6 +1203,7 @@ static struct xenbus_driver netback_driver = { > > .remove = netback_remove, > > .uevent = netback_uevent, > > .otherend_changed = frontend_changed, > > + .use_mtwatch = true, > > Is there a special reason why kernel based backends shouldn't all use > the multithread model? This would avoid the need for the use_mtwatch > struct member. > > This is meant as an honest question. I'm really not sure we should > switch all backends at once. OTOH I can't see any real downsides. > > Thoughts? I don't see any downside. Wei. > > > Juergen