From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S265288AbUHDNRW (ORCPT ); Wed, 4 Aug 2004 09:17:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S265331AbUHDNRV (ORCPT ); Wed, 4 Aug 2004 09:17:21 -0400 Received: from e31.co.us.ibm.com ([32.97.110.129]:33684 "EHLO e31.co.us.ibm.com") by vger.kernel.org with ESMTP id S265288AbUHDNRQ (ORCPT ); Wed, 4 Aug 2004 09:17:16 -0400 Subject: Re: CPU hotplug broken in 2.6.8-rc2 ? From: Nathan Lynch To: vatsa@in.ibm.com Cc: dipankar@in.ibm.com, Joel Schopp , Rusty Russell , lkml , Nick Piggin , zwane@linuxpower.ca In-Reply-To: <20040804100642.GA20278@in.ibm.com> References: <20040802094907.GA3945@in.ibm.com> <20040802095741.GA4599@in.ibm.com> <1091475519.29556.4.camel@pants.austin.ibm.com> <1091478386.29556.36.camel@pants.austin.ibm.com> <1091567239.28036.36.camel@biclops.private.network> <20040804100642.GA20278@in.ibm.com> Content-Type: text/plain Message-Id: <1091625124.9360.14.camel@biclops.private.network> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.6 Date: Wed, 04 Aug 2004 08:12:05 -0500 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2004-08-04 at 05:06, Srivatsa Vaddagiri wrote: > On Tue, Aug 03, 2004 at 04:07:20PM -0500, Nathan Lynch wrote: > > BUG_ON(rq->nr_running != 0); > > > > I can reproduce this on both ppc64 and i386. Does anyone know why this > > is happening? > > I guess some task is still stuck with the dead CPU. Can you put a breakpoint on the BUG_ON > and see the ps output (in kdb) to see which task is that when you hit the breakpoint? The task is always something like cc1 or sh from the build which is running. > > I will also try debugging the 2.6.8-rc2 CPU Hotplug woes as soon as I can. > Well, I am seeing this with 2.6.8-rc2-mm2 -- with 2.6.8-rc2-bk13 (plus the same patch) I cannot reproduce it; I have run the test for 12 hours without problem. Nathan