From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f171.google.com (mail-pd0-f171.google.com [209.85.192.171]) by kanga.kvack.org (Postfix) with ESMTP id 432AA6B0038 for ; Sun, 22 Mar 2015 22:00:31 -0400 (EDT) Received: by pdbop1 with SMTP id op1so171582677pdb.2 for ; Sun, 22 Mar 2015 19:00:31 -0700 (PDT) Received: from shards.monkeyblade.net (shards.monkeyblade.net. [2001:4f8:3:36:211:85ff:fe63:a549]) by mx.google.com with ESMTP id ti6si19350610pab.223.2015.03.22.19.00.28 for ; Sun, 22 Mar 2015 19:00:29 -0700 (PDT) Date: Sun, 22 Mar 2015 22:00:24 -0400 (EDT) Message-Id: <20150322.220024.1171832215344978787.davem@davemloft.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> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: 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 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. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org