From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f182.google.com (mail-pd0-f182.google.com [209.85.192.182]) by kanga.kvack.org (Postfix) with ESMTP id 4A91C6B0031 for ; Thu, 6 Mar 2014 20:06:17 -0500 (EST) Received: by mail-pd0-f182.google.com with SMTP id g10so3305795pdj.13 for ; Thu, 06 Mar 2014 17:06:16 -0800 (PST) Received: from userp1040.oracle.com (userp1040.oracle.com. [156.151.31.81]) by mx.google.com with ESMTPS id tk9si6554470pac.64.2014.03.06.17.06.15 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Thu, 06 Mar 2014 17:06:15 -0800 (PST) Message-ID: <53191B05.20102@oracle.com> Date: Thu, 06 Mar 2014 20:04:05 -0500 From: Sasha Levin MIME-Version: 1.0 Subject: Re: [PATCH -mm] mm,numa,mprotect: always continue after finding a stable thp page References: <5318E4BC.50301@oracle.com> <20140306173137.6a23a0b2@cuia.bos.redhat.com> In-Reply-To: <20140306173137.6a23a0b2@cuia.bos.redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Rik van Riel Cc: David Rientjes , Andrew Morton , "linux-mm@kvack.org" , LKML , mgorman@suse.de, hhuang@redhat.com, knoel@redhat.com, aarcange@redhat.com On 03/06/2014 05:31 PM, Rik van Riel wrote: > On Thu, 06 Mar 2014 16:12:28 -0500 > Sasha Levin wrote: > >> >While fuzzing with trinity inside a KVM tools guest running latest -next kernel I've hit the >> >following spew. This seems to be introduced by your patch "mm,numa: reorganize change_pmd_range()". > That patch should not introduce any functional changes, except for > the VM_BUG_ON that catches the fact that we fell through to the 4kB > pte handling code, despite having just handled a THP pmd... > > Does this patch fix the issue? I'm seeing a different issue with this patch: [ 625.886532] BUG: unable to handle kernel NULL pointer dereference at 0000000000000018 [ 625.888056] IP: [] __lock_acquire+0xbc/0x580 [ 625.888969] PGD 427842067 PUD 41b321067 PMD 0 [ 625.889775] Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC [ 625.890773] Dumping ftrace buffer: [ 625.891454] (ftrace buffer empty) [ 625.892041] Modules linked in: [ 625.892610] CPU: 9 PID: 18991 Comm: trinity-c198 Tainted: G W 3.14.0-rc5-next-20140305-sasha-00012-g00c5c8f-dirty #110 [ 625.894293] task: ffff8804278cb000 ti: ffff88041d89a000 task.ti: ffff88041d89a000 [ 625.895678] RIP: 0010:[] [] __lock_acquire+0xbc/0x580 [ 625.896232] RSP: 0018:ffff88041d89bbe8 EFLAGS: 00010002 [ 625.896232] RAX: 0000000000000082 RBX: 0000000000000018 RCX: 0000000000000000 [ 625.896232] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000018 [ 625.896232] RBP: ffff88041d89bc58 R08: 0000000000000001 R09: 0000000000000000 [ 625.896232] R10: 0000000000000001 R11: 0000000000000001 R12: ffff8804278cb000 [ 625.896232] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000001 [ 625.896232] FS: 00007f144ab81700(0000) GS:ffff880a2b800000(0000) knlGS:0000000000000000 [ 625.896232] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 625.896232] CR2: 0000000000000018 CR3: 00000004290cf000 CR4: 00000000000006a0 [ 625.896232] Stack: [ 625.896232] ffff8802295abc18 ffff8804278cb000 ffff880a2b9d84c0 ffff880a2b9d84d0 [ 625.896232] ffff88041d89bc18 ffffffff810bb084 ffff88041d89bc28 ffffffff8107912d [ 625.896232] ffff88041d89bc58 ffff8804278cb000 0000000000000000 0000000000000001 [ 625.896232] Call Trace: [ 625.896232] [] ? kvm_clock_read+0x24/0x50 [ 625.896232] [] ? sched_clock+0x1d/0x30 [ 625.896232] [] lock_acquire+0x182/0x1d0 [ 625.896232] [] ? change_pte_range+0xa3/0x3b0 [ 625.896232] [] ? sched_clock+0x1d/0x30 [ 625.896232] [] _raw_spin_lock+0x40/0x80 [ 625.896232] [] ? change_pte_range+0xa3/0x3b0 [ 625.896232] [] change_pte_range+0xa3/0x3b0 [ 625.896232] [] change_protection_range+0x3a8/0x4d0 [ 625.896232] [] ? preempt_count_sub+0xe2/0x120 [ 625.896232] [] change_protection+0x25/0x30 [ 625.896232] [] change_prot_numa+0x1b/0x30 [ 625.896232] [] task_numa_work+0x279/0x360 [ 625.896232] [] task_work_run+0xae/0xf0 [ 625.896232] [] do_notify_resume+0x8e/0xe0 [ 625.896232] [] int_signal+0x12/0x17 [ 625.896232] Code: c2 37 f6 6b 85 be fa 0b 00 00 48 c7 c7 a1 4f 6c 85 e8 09 60 f9 ff 31 c0 e9 9c 04 00 00 66 90 44 8b 1d 39 1f cd 04 45 85 db 74 0c <48> 81 3b 40 52 76 87 75 06 0f 1f 00 45 31 c0 83 fe 01 77 0c 89 [ 625.896232] RIP [] __lock_acquire+0xbc/0x580 [ 625.896232] RSP [ 625.896232] CR2: 0000000000000018 Thanks, Sasha -- 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