From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx174.postini.com [74.125.245.174]) by kanga.kvack.org (Postfix) with SMTP id 7CF4D6B005D for ; Fri, 14 Sep 2012 18:39:51 -0400 (EDT) Received: by weys10 with SMTP id s10so3240961wey.14 for ; Fri, 14 Sep 2012 15:39:49 -0700 (PDT) Message-ID: <5053B24D.8010005@gmail.com> Date: Sat, 15 Sep 2012 00:40:13 +0200 From: Sasha Levin MIME-Version: 1.0 Subject: Re: [PATCH 6/7] mm: add CONFIG_DEBUG_VM_RB build option References: <1346750457-12385-1-git-send-email-walken@google.com> <1346750457-12385-7-git-send-email-walken@google.com> <5053AC2F.3070203@gmail.com> In-Reply-To: <5053AC2F.3070203@gmail.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Michel Lespinasse Cc: linux-mm@kvack.org, riel@redhat.com, peterz@infradead.org, aarcange@redhat.com, hughd@google.com, daniel.santos@pobox.com, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, Dave Jones On 09/15/2012 12:14 AM, Sasha Levin wrote: > On 09/04/2012 11:20 AM, Michel Lespinasse wrote: >> Add a CONFIG_DEBUG_VM_RB build option for the previously existing >> DEBUG_MM_RB code. Now that Andi Kleen modified it to avoid using >> recursive algorithms, we can expose it a bit more. >> >> Also extend this code to validate_mm() after stack expansion, and to >> check that the vma's start and last pgoffs have not changed since the >> nodes were inserted on the anon vma interval tree (as it is important >> that the nodes be reindexed after each such update). > > This patch exposes the following warning: > > [ 24.977502] ------------[ cut here ]------------ > [ 24.979089] WARNING: at mm/interval_tree.c:110 > anon_vma_interval_tree_verify+0x81/0xa0() > [ 24.981765] Pid: 5928, comm: trinity-child37 Tainted: G W > 3.6.0-rc5-next-20120914-sasha-00003-g7deb7fa-dirty #333 > [ 24.985501] Call Trace: > [ 24.986345] [] ? anon_vma_interval_tree_verify+0x81/0xa0 > [ 24.988535] [] warn_slowpath_common+0x86/0xb0 > [ 24.990636] [] warn_slowpath_null+0x15/0x20 > [ 24.992658] [] anon_vma_interval_tree_verify+0x81/0xa0 > [ 24.994980] [] validate_mm+0x58/0x1e0 > [ 24.996772] [] vma_link+0x94/0xe0 > [ 24.997719] [] copy_vma+0x279/0x2e0 > [ 24.998522] [] ? trace_hardirqs_off+0xd/0x10 > [ 25.000772] [] move_vma+0xa9/0x260 > [ 25.002499] [] sys_mremap+0x475/0x540 > [ 25.004364] [] tracesys+0xe1/0xe6 > [ 25.006108] ---[ end trace 7c901670963aa6e2 ]--- > > The code line is > > WARN_ON_ONCE(node->cached_vma_last != avc_last_pgoff(node)); > The second WARN in the function also triggers once in a while: [ 18.360283] ------------[ cut here ]------------ [ 18.360289] WARNING: at mm/interval_tree.c:109 anon_vma_interval_tree_verify+0x36/0xa0() [ 18.360292] Pid: 5694, comm: trinity-child15 Tainted: G W 3.6.0-rc5-next-20120914-sasha-00003-g7deb7fa-dirty #335 [ 18.360293] Call Trace: [ 18.360297] [] ? anon_vma_interval_tree_verify+0x36/0xa0 [ 18.360300] [] warn_slowpath_common+0x86/0xb0 [ 18.360303] [] warn_slowpath_null+0x15/0x20 [ 18.360305] [] anon_vma_interval_tree_verify+0x36/0xa0 [ 18.360309] [] validate_mm+0x58/0x1e0 [ 18.360312] [] vma_link+0x94/0xe0 [ 18.360315] [] copy_vma+0x279/0x2e0 [ 18.360319] [] ? trace_hardirqs_off+0xd/0x10 [ 18.360322] [] move_vma+0xa9/0x260 [ 18.360326] [] sys_mremap+0x475/0x540 [ 18.360330] [] tracesys+0xe1/0xe6 [ 18.360332] ---[ end trace de862a218d00cefd ]--- -- 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