From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andi Kleen Subject: Re: [PATCH/RFC] synchronize_rcu(): high latency on idle system Date: Sun, 13 Jan 2008 16:34:17 +0100 Message-ID: <200801131634.17677.ak@suse.de> References: <20080112012626.GI28570@kvack.org> <200801121935.58286.ak@suse.de> <20080112175226.7d8f9dbc@deepthought> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, linux-kerne@vger.kernel.org To: Stephen Hemminger Return-path: Received: from ns.suse.de ([195.135.220.2]:57375 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751226AbYAMPeV (ORCPT ); Sun, 13 Jan 2008 10:34:21 -0500 In-Reply-To: <20080112175226.7d8f9dbc@deepthought> Content-Disposition: inline Sender: netdev-owner@vger.kernel.org List-ID: > I think it should be in netdev_unregister_kobject(). But that would > only get rid of one of the two calls to synchronize_rcu() in the unregister_netdev. Would be already an improvement. > The other synchronize_rcu() is for qdisc's and not sure if that one can > be removed? The standard way to remove such calls is to set a "deleted" flag in the object, then check and ignore such objects in the reader and finally remove the object with call_rcu I have not checked if that is really feasible for qdiscs. -Andi