From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 23 Jul 2002 16:45:10 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 23 Jul 2002 16:45:10 -0400 Received: from holomorphy.com ([66.224.33.161]:48013 "EHLO holomorphy") by vger.kernel.org with ESMTP id ; Tue, 23 Jul 2002 16:45:09 -0400 Date: Tue, 23 Jul 2002 13:47:45 -0700 From: William Lee Irwin III To: george anzinger Cc: Zwane Mwaikambo , Trond Myklebust , Linux Kernel Subject: Re: odd memory corruption in 2.5.27? Message-ID: <20020723204745.GM919@holomorphy.com> Mail-Followup-To: William Lee Irwin III , george anzinger , Zwane Mwaikambo , Trond Myklebust , Linux Kernel References: <3D3DBD4B.4EFD3543@mvista.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Description: brief message Content-Disposition: inline In-Reply-To: <3D3DBD4B.4EFD3543@mvista.com> User-Agent: Mutt/1.3.25i Organization: The Domain of Holomorphy Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 23, 2002 at 01:32:11PM -0700, george anzinger wrote: > I just spent a month tracking down this issue. It comes > down to the slab allocater using per cpu data structures and > protecting them with a combination of interrupt disables and > spin_locks. Preemption is allowed (incorrectly) if > interrupts are off and preempt_count goes to zero on the > spin_unlock. I will wager that this is an SMP machine. > After the preemption interrupts will be on (schedule() does > that) AND you could be on a different cpu. Either of these > is a BAD thing. > The proposed fix is to catch the attempted preemption in > preempt_schedule() and just return if the interrupt system > is off. (Of course there is more that this to it, but I do > believe that the problem is known. You could blow this > assertion out of the water by asserting that the machine is > NOT smp.) I've been seeing the slab allocator race like mad already (i.e. BUG at slab.c:1947 and slab.c:1961. I'll test this fix. Thanks, Bill