From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751213AbWF1UFs (ORCPT ); Wed, 28 Jun 2006 16:05:48 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751200AbWF1UFs (ORCPT ); Wed, 28 Jun 2006 16:05:48 -0400 Received: from ausmtp05.au.ibm.com ([202.81.18.154]:56981 "EHLO ausmtp05.au.ibm.com") by vger.kernel.org with ESMTP id S1751222AbWF1UFq (ORCPT ); Wed, 28 Jun 2006 16:05:46 -0400 Date: Thu, 29 Jun 2006 01:32:47 +0530 From: Dipankar Sarma To: Ingo Molnar Cc: linux-kernel@vger.kernel.org, Ananth N Mavinakayanahalli , Prasanna Panchamukhi Subject: Re: [PATCH] 2.6.17-rt1 : fix x86_64 oops Message-ID: <20060628200247.GA7932@in.ibm.com> Reply-To: dipankar@in.ibm.com References: <20060627200105.GA13966@in.ibm.com> <20060628182137.GA23979@in.ibm.com> <20060628193256.GA4392@elte.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20060628193256.GA4392@elte.hu> User-Agent: Mutt/1.5.11 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jun 28, 2006 at 09:32:56PM +0200, Ingo Molnar wrote: > > * Dipankar Sarma wrote: > > > Turns out that kprobe_flush_task() is called from finish_task_switch() > > with preemption disabled and it uses a converted spin lock. The > > following patch fixed the problem for me and I was able to boot my > > x86_64 box. > > ah, subtle problem and nice fix! We are using an RCU trick to delay task > freeing in finish_task_switch(), but kprobe_flush_task() isnt done in Yes, otherwise it would have been hell to do __put_task_struct() with preemption disabled. > put_task_struct(). [neither would it be right to flush kprobes there.] > I've released -rt4 with this included. OK, I need to catch up, but I see a lot of oops while running rcutorture in my box (rt1). I am investigating this atm. Thanks Dipankar