From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751901AbZHaKIU (ORCPT ); Mon, 31 Aug 2009 06:08:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750872AbZHaKIT (ORCPT ); Mon, 31 Aug 2009 06:08:19 -0400 Received: from fg-out-1718.google.com ([72.14.220.157]:36267 "EHLO fg-out-1718.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750813AbZHaKIS convert rfc822-to-8bit (ORCPT ); Mon, 31 Aug 2009 06:08:18 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:content-type :content-transfer-encoding; b=MFhGNQauzc2RmJtk53Kjyw954VvMAsRnyRqD0nMxc+YX/qxR0A+Cq5/i7E72zTZmAn zTzNE8kvWyM1IY7NAN7C9AKl1LoQ5c7jP8z0zVzNnZ+AxjlVBs069in4YWIL+9whhnRt cf0UcEZrniwX/PBfzLnuF0bfH5qBHTW/KAd3w= MIME-Version: 1.0 In-Reply-To: <20090831074842.GA28091@linux-sh.org> References: <20090831074842.GA28091@linux-sh.org> Date: Mon, 31 Aug 2009 13:08:19 +0300 X-Google-Sender-Auth: c5b2163849d4420e Message-ID: <84144f020908310308i48790f78g5a7d73a60ea854f8@mail.gmail.com> Subject: Re: page allocator regression on nommu From: Pekka Enberg To: Paul Mundt , Mel Gorman , Christoph Lameter , KOSAKI Motohiro , Pekka Enberg , Peter Zijlstra , Nick Piggin , Dave Hansen , Lee Schermerhorn , Andrew Morton , Linus Torvalds , David Howells , linux-mm@kvack.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Paul, On Mon, Aug 31, 2009 at 10:48 AM, Paul Mundt wrote: > It seems we've managed to trigger a fairly interesting conflict between > the anti-fragmentation disabling code and the nommu region rbtree. I've > bisected it down to: > > commit 49255c619fbd482d704289b5eb2795f8e3b7ff2e > Author: Mel Gorman > Date:   Tue Jun 16 15:31:58 2009 -0700 > >    page allocator: move check for disabled anti-fragmentation out of fastpath > >    On low-memory systems, anti-fragmentation gets disabled as there is >    nothing it can do and it would just incur overhead shuffling pages between >    lists constantly.  Currently the check is made in the free page fast path >    for every page.  This patch moves it to a slow path.  On machines with low >    memory, there will be small amount of additional overhead as pages get >    shuffled between lists but it should quickly settle. > > which causes death on unpacking initramfs on my nommu board. With this > reverted, everything works as expected. Note that this blows up with all of > SLOB/SLUB/SLAB. > > I'll continue debugging it, and can post my .config if it will be helpful, but > hopefully you have some suggestions on what to try :-) > > --- > > modprobe: page allocation failure. order:7, mode:0xd0 OK, so we have order 7 page allocation here... > Stack: (0x0c909d2c to 0x0c90a000) > 9d20:                            0c0387d2 00000000 00000000 0c107fcc 00000000 > 9d40: 00000000 0c107fcc 0c2f8960 00000000 00000010 00000000 00000000 000200d0 > 9d60: 00000000 0c041614 0c9f8cf4 00000000 0c9f8d1c 00000000 00000004 00000000 > 9d80: 00000007 0c01a582 0c2f8cd0 00000000 00000000 00049000 00000049 00048fff > 9da0: 00049fff 00049000 00000007 0c06633a 00000001 0c909f30 0003e950 0c0bad00 > 9dc0: 0000984a 0c2f8ea0 ffffe000 00000002 00000000 0c065314 0c2f8ea0 0c077f60 > 9de0: 00049000 0000673c 00000050 000369a0 000019cf 00000004 00004e20 0003e950 > 9e00: 000481aa 00000001 00004eaa 000049a0 00007fb0 000369a0 00000000 00000000 > 9e20: 0c909e50 00000000 00000000 0c066790 00000000 0c909f30 00000000 00000000 > 9e40: 0c2f8ea0 0c909f30 0c909e50 00004eaa 00000000 00000000 00000000 00000000 > 9e60: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 > 9e80: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 > 9ea0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 > 9ec0: 0c0482ee 00000000 fffffff8 0c2f8ea0 0c104ff8 0c04884e 0c0feb64 00000001 > 9ee0: 0c048570 ffffe000 0c2f8ea0 00000000 00000000 0c813eb8 0c909f30 0c002e68 > 9f00: 00000000 00000000 00000000 0c0feb64 0c813eb8 0c909f30 0c960000 0c007972 > 9f20: ffffff0f 00000071 00000100 0c002e38 0000000b ffffff0f 00000001 0000000b > 9f40: 0c0fea64 0c813eb8 0c0feb64 0c2f898c 00000000 ffffe000 0c9f8990 00000000 > 9f60: 00000000 00000000 00000000 0c909f8c 0c0050ca 0c01e874 40000001 00000000 > 9f80: 00000000 4795ce40 0000004c 0c002cca 00000000 00000000 00000000 00000000 > 9fa0: 00000000 00000000 00000000 00000000 00000000 0c9f8990 0c01e7a4 00000000 > 9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 > 9fe0: 0c909f9c 0c002cc4 00000000 40000000 00000000 00000000 00000000 00000000 > > Call trace: >  [<0c041614>] do_mmap_pgoff+0x638/0xa68 >  [<0c01a582>] flush_itimer_signals+0x36/0x60 >  [<0c06633a>] load_flat_file+0x32a/0x738 >  [<0c0bad00>] down_write+0x0/0xc >  [<0c065314>] load_elf_fdpic_binary+0x44/0xa8c >  [<0c077f60>] memset+0x0/0x60 >  [<0c066790>] load_flat_binary+0x48/0x2fc >  [<0c0482ee>] search_binary_handler+0x4a/0x1fc >  [<0c04884e>] do_execve+0x156/0x2bc >  [<0c048570>] copy_strings+0x0/0x150 >  [<0c002e68>] sys_execve+0x30/0x5c >  [<0c007972>] syscall_call+0xc/0x10 >  [<0c002e38>] sys_execve+0x0/0x5c >  [<0c0050ca>] kernel_execve+0x6/0xc >  [<0c01e874>] ____call_usermodehelper+0xd0/0xfc >  [<0c002cca>] kernel_thread_helper+0x6/0x10 >  [<0c01e7a4>] ____call_usermodehelper+0x0/0xfc >  [<0c002cc4>] kernel_thread_helper+0x0/0x10 > > Mem-Info: > Normal per-cpu: > CPU    0: hi:    0, btch:   1 usd:   0 > Active_anon:0 active_file:0 inactive_anon:0 >  inactive_file:0 unevictable:323 dirty:0 writeback:0 unstable:0 >  free:2967 slab:0 mapped:0 pagetables:0 bounce:0 > Normal free:11868kB min:0kB low:0kB high:0kB active_anon:0kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:1292kB present:16256kB pages_scanned:0 all_unreclaimable? no > lowmem_reserve[]: 0 0 > Normal: 267*4kB 268*8kB 251*16kB 145*32kB 0*64kB 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB 0*8192kB 0*16384kB 0*32768kB = 11868kB ...but we seem to be all out of order > 3 pages. I'm not sure why commit 49255c619fbd482d704289b5eb2795f8e3b7ff2e changes any of this, though. > 323 total pagecache pages > ------------[ cut here ]------------ > kernel BUG at mm/nommu.c:598! > Kernel BUG: 003e [#1] > Modules linked in: > > Pid : 51, Comm:                 modprobe > CPU : 0                 Not tainted  (2.6.31-rc7 #2835) > > PC is at __put_nommu_region+0xe/0xb0 > PR is at do_mmap_pgoff+0x8dc/0xa68 This looks to be a bug in nommu do_mmap_pgoff() error handling. I guess we shouldn't call __put_nommu_region() if add_nommu_region() hasn't been called? > PC  : 0c040e7a SP  : 0c909d7c SR  : 40000001 > R0  : 0000001d R1  : 00000000 R2  : 00000000 R3  : 0000000d > R4  : 0c9f8cf4 R5  : 000017de R6  : ffffffff R7  : 00000035 > R8  : 0c9f8cf4 R9  : 00000000 R10 : 00000000 R11 : fffffff4 > R12 : 0c9f8d1c R13 : 00000000 R14 : 0c9f8cf4 > MACH: 0000017e MACL: baf11680 GBR : 00000000 PR  : 0c0418b8 > > Call trace: >  [<0c0418b8>] do_mmap_pgoff+0x8dc/0xa68 >  [<0c01a582>] flush_itimer_signals+0x36/0x60 >  [<0c06633a>] load_flat_file+0x32a/0x738 >  [<0c0bad00>] down_write+0x0/0xc >  [<0c065314>] load_elf_fdpic_binary+0x44/0xa8c >  [<0c077f60>] memset+0x0/0x60 >  [<0c066790>] load_flat_binary+0x48/0x2fc >  [<0c0482ee>] search_binary_handler+0x4a/0x1fc >  [<0c04884e>] do_execve+0x156/0x2bc >  [<0c048570>] copy_strings+0x0/0x150 >  [<0c002e68>] sys_execve+0x30/0x5c >  [<0c007972>] syscall_call+0xc/0x10 >  [<0c002e38>] sys_execve+0x0/0x5c >  [<0c0050ca>] kernel_execve+0x6/0xc >  [<0c01e874>] ____call_usermodehelper+0xd0/0xfc >  [<0c002cca>] kernel_thread_helper+0x6/0x10 >  [<0c01e7a4>] ____call_usermodehelper+0x0/0xfc >  [<0c002cc4>] kernel_thread_helper+0x0/0x10 > > Code: >  0c040e74:  tst       r1, r1 >  0c040e76:  bf.s      0c040e7c >  0c040e78:  mov       r4, r8 > ->0c040e7a:  trapa     #62 >  0c040e7c:  stc       sr, r1 >  0c040e7e:  mov       r1, r0 >  0c040e80:  or        #-16, r0 >  0c040e82:  ldc       r0, sr >  0c040e84:  mov       r1, r0 > > Process: modprobe (pid: 51, stack limit = 0c908001) > Stack: (0x0c909d7c to 0x0c90a000) > 9d60:                                                                0c0418b8 > 9d80: 00000007 0c01a582 0c2f8cd0 00000000 00000000 00049000 00000049 00048fff > 9da0: 00049fff 00049000 00000007 0c06633a 00000001 0c909f30 0003e950 0c0bad00 > 9dc0: 0000984a 0c2f8ea0 ffffe000 00000002 00000000 0c065314 0c2f8ea0 0c077f60 > 9de0: 00049000 0000673c 00000050 000369a0 000019cf 00000004 00004e20 0003e950 > 9e00: 000481aa 00000001 00004eaa 000049a0 00007fb0 000369a0 00000000 00000000 > 9e20: 0c909e50 00000000 00000000 0c066790 00000000 0c909f30 00000000 00000000 > 9e40: 0c2f8ea0 0c909f30 0c909e50 00004eaa 00000000 00000000 00000000 00000000 > 9e60: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 > 9e80: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 > 9ea0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 > 9ec0: 0c0482ee 00000000 fffffff8 0c2f8ea0 0c104ff8 0c04884e 0c0feb64 00000001 > 9ee0: 0c048570 ffffe000 0c2f8ea0 00000000 00000000 0c813eb8 0c909f30 0c002e68 > 9f00: 00000000 00000000 00000000 0c0feb64 0c813eb8 0c909f30 0c960000 0c007972 > 9f20: ffffff0f 00000071 00000100 0c002e38 0000000b ffffff0f 00000001 0000000b > 9f40: 0c0fea64 0c813eb8 0c0feb64 0c2f898c 00000000 ffffe000 0c9f8990 00000000 > 9f60: 00000000 00000000 00000000 0c909f8c 0c0050ca 0c01e874 40000001 00000000 > 9f80: 00000000 4795ce40 0000004c 0c002cca 00000000 00000000 00000000 00000000 > 9fa0: 00000000 00000000 00000000 00000000 00000000 0c9f8990 0c01e7a4 00000000 > 9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 > 9fe0: 0c909f9c 0c002cc4 00000000 40000000 00000000 00000000 00000000 00000000 > ---[ end trace 139ce121c98e96c9 ]--- > > -- > 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 >