From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f169.google.com (mail-pd0-f169.google.com [209.85.192.169]) by kanga.kvack.org (Postfix) with ESMTP id 812C76B0032 for ; Wed, 1 Apr 2015 16:13:25 -0400 (EDT) Received: by pddn5 with SMTP id n5so65583954pdd.2 for ; Wed, 01 Apr 2015 13:13:25 -0700 (PDT) Received: from aserp1040.oracle.com (aserp1040.oracle.com. [141.146.126.69]) by mx.google.com with ESMTPS id fu7si4357880pdb.48.2015.04.01.13.13.22 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Wed, 01 Apr 2015 13:13:23 -0700 (PDT) Message-ID: <551C515C.5050807@oracle.com> Date: Wed, 01 Apr 2015 16:13:16 -0400 From: Sasha Levin MIME-Version: 1.0 Subject: Re: kernel 3.18.10: THP refcounting bug References: <551BBE1A.4040404@profihost.ag> <20150401113122.GA17153@node.dhcp.inet.fi> <551BDB8F.4070707@profihost.ag> <551C12CC.3000803@oracle.com> <551C39EE.90504@profihost.ag> In-Reply-To: <551C39EE.90504@profihost.ag> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Stefan Priebe Cc: "Kirill A. Shutemov" , "linux-mm@kvack.org" , Hugh Dickins , Konstantin Khlebnikov linux-mm@ was incorrect in the original mail so this ended up getting around just between us. Below is Stefan's response to my question about the 'B' taint flag. On 04/01/2015 02:33 PM, Stefan Priebe wrote: > > Am 01.04.2015 um 17:46 schrieb Sasha Levin: >> On 04/01/2015 07:50 AM, Stefan Priebe - Profihost AG wrote: >>> Hi, >>> >>> while using 3.18.9 i got several times the following stack trace: >>> >>> kernel BUG at mm/filemap.c:203! >>> invalid opcode: 0000 [#1] SMP >>> Modules linked in: dm_mod netconsole usbhid sd_mod sg ata_generic >>> virtio_net virtio_scsi uhci_hcd ehci_hcd usbcore virtio_pci usb_common >>> virtio_ring ata_piix virtio floppy >>> CPU: 3 PID: 1 Comm: busybox Tainted: G B 3.18.9 #1 >> >> Looking at the taint flags, was there anything else before this that >> could set the 'B' flag? > > oh i'm sorry you're correct before that one i see (happens on shutdown): > > BUG: Bad page map in process udevd pte:ba4a2025 pmd:ba275067 > page:ffffea0002e92880 count:1 mapcount:-1 mapping:ffff8800bba8c4c8 index:0x10 > flags: 0x1fffff8000007c(referenced|uptodate|dirty|lru|active) > page dumped because: bad pte > addr:0000000000410000 vm_flags:00000875 anon_vma: (null) mapping:ffff8800bba8c4c8 index:10 > vma->vm_ops->fault: filemap_fault+0x0/0x480 > vma->vm_file->f_op->mmap: generic_file_mmap+0x0/0x60 > CPU: 7 PID: 105 Comm: udevd Not tainted 3.18.9+14-ph #1 > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5.1-0-g8936dbb-20141113_115728-nilsson.home.kraxel.org 04/01/201 > 4 > ffff880136ca58c0 ffff8800b9c8bc58 ffffffff815f0732 00000000072b072b > 0000000000410000 ffff8800b9c8bca8 ffffffff8115b5b6 00000000ba4a2025 > 0000000000000010 ffff8800b9c8bca8 0000000000424000 ffff8800ba275080 > Call Trace: > [] dump_stack+0x46/0x58 > [] print_bad_pte+0x196/0x240 > [] unmap_single_vma+0x729/0x7f0 > [] unmap_vmas+0x51/0xa0 > [] exit_mmap+0xc5/0x170 > [] mmput+0x55/0x100 > [] do_exit+0x25d/0xa30 > [] ? do_munmap+0x30f/0x3b0 > [] do_group_exit+0x3f/0xa0 > [] SyS_exit_group+0x17/0x20 > [] system_call_fastpath+0x12/0x17 > Disabling lock debugging due to kernel taint > BUG: Bad page state in process udevd pfn:ba4a2 > page:ffffea0002e92880 count:0 mapcount:-1 mapping:ffff8800bba8c4c8 index:0x10 > flags: 0x1fffff8000001c(referenced|uptodate|dirty) > page dumped because: non-NULL mapping > Modules linked in: dm_mod netconsole usbhid sd_mod sg ata_generic virtio_net virtio_scsi uhci_hcd ehci_hcd usbcore virtio_pci usb_co > mmon virtio_ring ata_piix virtio floppy > CPU: 7 PID: 105 Comm: udevd Tainted: G B 3.18.9+14-ph #1 > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5.1-0-g8936dbb-20141113_115728-nilsson.home.kraxel.org 04/01/201 > 4 > ffffffff81805618 ffff8800b9c8bba8 ffffffff815f0732 0000000007700770 > ffffea0002e92880 ffff8800b9c8bbd8 ffffffff815eb801 0000000000000000 > ffffea0002e92880 0000000000000000 000fffff80000000 ffff8800b9c8bc28 > Call Trace: > [] dump_stack+0x46/0x58 > [] bad_page+0xf7/0x115 > [] free_pages_prepare+0x152/0x180 > [] free_hot_cold_page+0x40/0x160 > [] free_hot_cold_page_list+0x4e/0xa0 > [] release_pages+0x1f3/0x280 > [] free_pages_and_swap_cache+0x8d/0xa0 > [] tlb_flush_mmu_free+0x34/0x60 > [] tlb_flush_mmu+0x24/0x30 > [] tlb_finish_mmu+0x14/0x40 > [] exit_mmap+0xf4/0x170 > [] mmput+0x55/0x100 > [] do_exit+0x25d/0xa30 > [] ? do_munmap+0x30f/0x3b0 > [] do_group_exit+0x3f/0xa0 > [] SyS_exit_group+0x17/0x20 > [] system_call_fastpath+0x12/0x17 > ------------[ cut here ]------------ > > > Stefan > >> >> >> 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