From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Kirill A. Shutemov" Subject: Re: crisv32 runtime failure in -next due to 'page-flags: define behavior SL*B-related flags on compound pages' Date: Mon, 21 Sep 2015 18:34:35 +0300 (EEST) Message-ID: <20150921153435.CE98C138@black.fi.intel.com> References: <55FAEA67.9000102@roeck-us.net> <20150918142507.GA30125@node.dhcp.inet.fi> <20150918145309.GG32685@axis.com> <55FC2A1F.8050207@roeck-us.net> Content-Transfer-Encoding: 7bit Return-path: Received: from mga02.intel.com ([134.134.136.20]:64291 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932164AbbIUPyf (ORCPT ); Mon, 21 Sep 2015 11:54:35 -0400 In-Reply-To: <55FC2A1F.8050207@roeck-us.net> Sender: linux-next-owner@vger.kernel.org List-ID: To: Guenter Roeck Cc: Jesper Nilsson , "Kirill A. Shutemov" , "linux-next@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "Kirill A. Shutemov" , Andrew Morton , Mikael Starvik , Jesper Nilsson , Minchan Kim , linux-cris-kernel@axis.com Guenter Roeck wrote: > On 09/18/2015 07:53 AM, Jesper Nilsson wrote: > > On Fri, Sep 18, 2015 at 05:25:07PM +0300, Kirill A. Shutemov wrote: > >> On Thu, Sep 17, 2015 at 09:29:27AM -0700, Guenter Roeck wrote: > >>> Hi, > >>> > >>> my crisv32 qemu test fails with next-20150917 as follows. > >>> > >>> NET: Registered protocol family 16 > >>> kernel BUG at mm/slab.c:1648! > >>> Linux 4.3.0-rc1-next-20150917 #1 Wed Sep 16 23:56:59 PDT 2015 > >>> Oops: 0000 > >>> > >>> [ register dump follows ] > >>> > >>> See http://server.roeck-us.net:8010/builders/qemu-crisv32-next/builds/83/steps/qemubuildcommand/logs/stdio > >>> for a complete log. > >> > >> Is there a chance to get proper backtrace? > > > > Yes, it should be possible with CONFIG_KALLSYMS=y in the kconfig. > > > > Good to know. I added it to my configuration. > > Here it is: > > kernel BUG at mm/slab.c:1648! I still don't understand what's going on :( Could you try with this instrumentation: diff --git a/mm/slab.c b/mm/slab.c index ce9c6531e6f7..10035d1a06d3 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -1645,7 +1645,11 @@ static void kmem_freepages(struct kmem_cache *cachep, struct page *page) sub_zone_page_state(page_zone(page), NR_SLAB_UNRECLAIMABLE, nr_freed); - BUG_ON(!PageSlab(page)); + if (!PageSlab(page)) { + dump_page(page, "page"); + dump_page(compound_head(page), "compound_head(page)"); + BUG(); + } __ClearPageSlabPfmemalloc(page); __ClearPageSlab(page); page_mapcount_reset(page); -- Kirill A. Shutemov