[Devel] WARNING at mm/slub.c

[Denis Kirjanov]

On 3/16/17, Denis Kirjanov <dkirjanov at cloudlinux.com> wrote:
> Hi guys,
>
> with the kernel rh7-3.10.0-327.36.1.vz7.18.7 we're seeing the
> following WARNING while running LTP test suite:
>
> [11796.576981] WARNING: at mm/slub.c:1252
> slab_pre_alloc_hook.isra.42.part.43+0x15/0x17()
>
> [11796.591008] Call Trace:
> [11796.592065]  [<ffffffff8164c468>] dump_stack+0x19/0x1b
> [11796.593076]  [<ffffffff8107b850>] warn_slowpath_common+0x70/0xb0
> [11796.594228]  [<ffffffff8107b99a>] warn_slowpath_null+0x1a/0x20
> [11796.595442]  [<ffffffff81649469>]
> slab_pre_alloc_hook.isra.42.part.43+0x15/0x17
> [11796.596686]  [<ffffffff811d8b68>] kmem_cache_alloc_trace+0x58/0x230
> [11796.597965]  [<ffffffff813126ee>] ? kmapset_new+0x1e/0x50
> [11796.599224]  [<ffffffff813126ee>] kmapset_new+0x1e/0x50
> [11796.600433]  [<ffffffff8127c7ba>] __sysfs_add_one+0x4a/0xb0
> [11796.601431]  [<ffffffff8127c83b>] sysfs_add_one+0x1b/0xd0
> [11796.602451]  [<ffffffff8127baa7>] sysfs_add_file_mode+0xb7/0x100
> [11796.603449]  [<ffffffff8127bb1a>] sysfs_create_file+0x2a/0x30
> [11796.604461]  [<ffffffff812fe12c>] kobject_add_internal+0x16c/0x2f0
> [11796.605503]  [<ffffffff812fe5b5>] kobject_add+0x75/0xd0
> [11796.606627]  [<ffffffff811d8d17>] ? kmem_cache_alloc_trace+0x207/0x230
> [11796.607655]  [<ffffffffa0563091>] __link_block_group+0xe1/0x120 [btrfs]
> [11796.608634]  [<ffffffffa05661a0>] btrfs_make_block_group+0x150/0x270
> [btrfs]
> [11796.609701]  [<ffffffffa059fd5f>] __btrfs_alloc_chunk+0x67f/0x8a0
> [btrfs]
> [11796.610756]  [<ffffffffa05a2eb4>] btrfs_alloc_chunk+0x34/0x40 [btrfs]
> [11796.611800]  [<ffffffffa055d62f>] do_chunk_alloc+0x23f/0x410 [btrfs]
> [11796.612954]  [<ffffffffa055e61a>]
> btrfs_check_data_free_space+0xea/0x280 [btrfs]
> [11796.614008]  [<ffffffffa05898a1>] __btrfs_buffered_write+0x151/0x5c0
> [btrfs]
> [11796.615153]  [<ffffffffa058d056>] btrfs_file_aio_write+0x246/0x560
> [btrfs]
> [11796.616141]  [<ffffffff811eae92>] ?
> __mem_cgroup_commit_charge+0x152/0x350
> [11796.617220]  [<ffffffff811faff0>] do_sync_write+0x90/0xe0
> [11796.618253]  [<ffffffff811fb81d>] vfs_write+0xbd/0x1e0
> [11796.619224]  [<ffffffff811fc2bf>] SyS_write+0x7f/0xe0
> [11796.620185]  [<ffffffff8165ccc9>] system_call_fastpath+0x16/0x1b
> [11796.621145] ---[ end trace 1437311f89b9e3c6 ]---
>

Guys, I've found your commit:

commit 149819fef38230c95f4d6c644061bc8b0dcdd51d
Author: Vladimir Davydov <vdavydov at parallels.com>
Date:   Fri Jun 5 13:20:02 2015 +0400

    mm/fs: Port diff-mm-debug-memallocation-caused-fs-reentrance

    Enable the debug once again, as the issue it found has been fixed:
    https://jira.sw.ru/browse/PSBM-34112

    Previous commit: 255427905323ac97a3c9b2d5acb2bf21ea2b31f6.

    Author: Dmitry Monakhov
    Email: dmonakhov at openvz.org
    Subject: mm: debug memallocation caused fs reentrance
    Date: Sun, 9 Nov 2014 11:53:14 +0400

But I can't open a link to figure out the original reason for the patch.



> Thanks!
>