From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261342AbVBPGQc (ORCPT ); Wed, 16 Feb 2005 01:16:32 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261941AbVBPGQc (ORCPT ); Wed, 16 Feb 2005 01:16:32 -0500 Received: from fsmlabs.com ([168.103.115.128]:7601 "EHLO fsmlabs.com") by vger.kernel.org with ESMTP id S261342AbVBPGQa (ORCPT ); Wed, 16 Feb 2005 01:16:30 -0500 Date: Tue, 15 Feb 2005 23:17:20 -0700 (MST) From: Zwane Mwaikambo To: Andrew Morton cc: linux-kernel@vger.kernel.org, rusty@rustcorp.com.au, mingo@elte.hu, nathanl@austin.ibm.com Subject: Re: [PATCH] Run softirqs on proper processor on offline In-Reply-To: <20050215215146.4c063baf.akpm@osdl.org> Message-ID: References: <20050211232821.GA14499@otto> <20050214215948.GA22304@otto> <20050215070217.GB13568@elte.hu> <20050216020628.GA25596@otto> <20050215215146.4c063baf.akpm@osdl.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 15 Feb 2005, Andrew Morton wrote: > Zwane Mwaikambo wrote: > > > > Ensure that we only offline the processor when it's safe and never run > > softirqs in another processor's ksoftirqd context. This also gets rid of > > the warnings in ksoftirqd on cpu offline. > > I don't get it. ksoftirqd is pinned to its cpu, so why does any of this > matter? We take down ksoftirqds at CPU_DEAD time, so there is a brief period whereupon there is a ksoftirqd thread for an offline processor, it is at this point that ->cpus_allowed won't have it pinned anymore. An online processor would then take down that ksoftirqd and exit it.