Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758617AbZATIVK (ORCPT ); Tue, 20 Jan 2009 03:21:10 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754356AbZATIUz (ORCPT ); Tue, 20 Jan 2009 03:20:55 -0500 Received: from cn.fujitsu.com ([222.73.24.84]:49819 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1754175AbZATIUz (ORCPT ); Tue, 20 Jan 2009 03:20:55 -0500 Message-ID: <49758937.5070300@cn.fujitsu.com> Date: Tue, 20 Jan 2009 16:20:07 +0800 From: Li Zefan User-Agent: Thunderbird 2.0.0.9 (X11/20071115) MIME-Version: 1.0 To: Ingo Molnar CC: Jaswinder Singh Rajput , Nick Piggin , Rusty Russell , Mike Travis , LKML Subject: Re: [BUG] kernel BUG at arch/x86/kernel/tlb_32.c:130! References: <49756F44.6040801@cn.fujitsu.com> <20090120075440.GA29426@elte.hu> <20090120081759.GA30394@elte.hu> In-Reply-To: <20090120081759.GA30394@elte.hu> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1583 Lines: 43 Ingo Molnar wrote: > * Ingo Molnar wrote: > >> * Li Zefan wrote: >> >>> I was using mmotm 2009-01-16-16-18, and I ran into this BUG, >>> the line is: >>> BUG_ON(cpumask_empty(cpumask)); >>> >>> I suspect it is caused by: >>> >>> commit 4595f9620cda8a1e973588e743cf5f8436dd20c6 >>> Author: Rusty Russell >>> Date: Sat Jan 10 21:58:09 2009 -0800 >>> >>> x86: change flush_tlb_others to take a const struct cpumask >>> >>> Impact: reduce stack usage, use new cpumask API. >> Jaswinder reported a similar crash. >> >> Mike, Rusty, what's going on with this commit? Why does this code: >> >> + if (cpumask_any_but(&mm->cpu_vm_mask, smp_processor_id()) < nr_cpu_ids) >> + flush_tlb_others(&mm->cpu_vm_mask, mm, TLB_FLUSH_ALL); >> >> Assume that mm->cpu_vm_mask wont change? TLB flushes go async and the >> MM's schedulability is not locked during that. I.e. mm->cpu_vm_mask can >> change under you while the TLB flush IPIs are flying around - while when >> the cpumask was passed on-stack this wouldnt happen. > > okay, a testsystem of mine just triggered this crash too. > > Li Zefan, Jaswinder, does the patch below fix it for you? > I'll test it, but I have to run for several hours to confirm it, since the bug is not easy to trigger. :) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/