From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752119AbbCWCAa (ORCPT ); Sun, 22 Mar 2015 22:00:30 -0400 Received: from shards.monkeyblade.net ([149.20.54.216]:50527 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751996AbbCWCA2 (ORCPT ); Sun, 22 Mar 2015 22:00:28 -0400 Date: Sun, 22 Mar 2015 22:00:24 -0400 (EDT) Message-Id: <20150322.220024.1171832215344978787.davem@davemloft.net> To: david.ahern@oracle.com Cc: torvalds@linux-foundation.org, sparclinux@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, bpicco@meloft.net Subject: Re: 4.0.0-rc4: panic in free_block From: David Miller In-Reply-To: <550F5852.5020405@oracle.com> References: <550F51D5.2010804@oracle.com> <20150322.195403.1653355516554747742.davem@davemloft.net> <550F5852.5020405@oracle.com> X-Mailer: Mew version 6.6 on Emacs 24.4 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Sun, 22 Mar 2015 19:00:28 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: David Ahern Date: Sun, 22 Mar 2015 18:03:30 -0600 > On 3/22/15 5:54 PM, David Miller wrote: >>> I just put it on 4.0.0-rc4 and ditto -- problem goes away, so it >>> clearly suggests the memcpy or memmove are the root cause. >> >> Thanks, didn't notice that. >> >> So, something is amuck. > > to continue to refine the problem ... I modified only the memmove > lines (not the memcpy) and it works fine. So its the memmove. > > I'm sure this will get whitespaced damaged on the copy and paste but > to be clear this is the patch I am currently running and system is > stable. On Friday it failed on every single; with this patch I have > allyesconfig builds with -j 128 in a loop (clean in between) and > nothing -- no panics. Can you just try calling memcpy(), that should work because I think we agree that if the memcpy() implementation copies from low to high it should work. I wonder if the triggering factor is configuring for a high number of cpus. I always have NR_CPUS=128 since that's the largest machine I have. I'll give NR_CPUS=1024 a spin.