On Fri, Sep 14, 2012 at 3:14 PM, Sasha Levin <levinsasha928@xxxxxxxxx> 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] [<ffffffff81224c91>] ? anon_vma_interval_tree_verify+0x81/0xa0 > [ 24.988535] [<ffffffff81106766>] warn_slowpath_common+0x86/0xb0 > [ 24.990636] [<ffffffff81106855>] warn_slowpath_null+0x15/0x20 > [ 24.992658] [<ffffffff81224c91>] anon_vma_interval_tree_verify+0x81/0xa0 > [ 24.994980] [<ffffffff8122e6e8>] validate_mm+0x58/0x1e0 > [ 24.996772] [<ffffffff8122e934>] vma_link+0x94/0xe0 > [ 24.997719] [<ffffffff812315e9>] copy_vma+0x279/0x2e0 > [ 24.998522] [<ffffffff8117a7fd>] ? trace_hardirqs_off+0xd/0x10 > [ 25.000772] [<ffffffff81232e89>] move_vma+0xa9/0x260 > [ 25.002499] [<ffffffff812334b5>] sys_mremap+0x475/0x540 > [ 25.004364] [<ffffffff8374b6e8>] tracesys+0xe1/0xe6 > [ 25.006108] ---[ end trace 7c901670963aa6e2 ]--- > > The code line is > > WARN_ON_ONCE(node->cached_vma_last != avc_last_pgoff(node)); That's very interesting (and potentially relevant to another bug that's been reported too). I'd like to know, what workload did you use that triggered this ? (I find it hard to test mremap as I don't know of enough users of it) Thanks, -- Michel "Walken" Lespinasse A program is never fully debugged until the last user dies. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>