Greetings,

I got the below dmesg and the first bad commit is

commit c65c1877bd6826ce0d9713d76e30a7bed8e49f38
Author:     Peter Zijlstra <peterz@infradead.org>
AuthorDate: Fri Jan 10 13:23:49 2014 +0100
Commit:     Pekka Enberg <penberg@kernel.org>
CommitDate: Mon Jan 13 21:34:39 2014 +0200

    slub: use lockdep_assert_held
    
    Instead of using comments in an attempt at getting the locking right,
    use proper assertions that actively warn you if you got it wrong.
    
    Also add extra braces in a few sites to comply with coding-style.
    
    Signed-off-by: Peter Zijlstra <peterz@infradead.org>
    Signed-off-by: Pekka Enberg <penberg@kernel.org>

===================================================
PARENT COMMIT NOT CLEAN. LOOK OUT FOR WRONG BISECT!
===================================================

+------------------------------------------------------------+--------------+--------------+
|                                                            | 8afb1474db47 | 4ce63c662360 |
+------------------------------------------------------------+--------------+--------------+
| boot_successes                                             | 67           | 0            |
| boot_failures                                              | 13           | 29           |
| WARNING:CPU:PID:at_kernel/events/core.c:perf_swevent_add() | 13           | 3            |
| WARNING:CPU:PID:at_mm/slub.c:__kmem_cache_create()         | 0            | 29           |
+------------------------------------------------------------+--------------+--------------+

[    0.000000]       .text : 0x41000000 - 0x41277e78   (2527 kB)
[    0.000000] Checking if this processor honours the WP bit even in supervisor mode...Ok.
[    0.000000] ------------[ cut here ]------------
[    0.000000] WARNING: CPU: 0 PID: 0 at mm/slub.c:1511 __kmem_cache_create+0x219/0x229()
[    0.000000] Modules linked in:
[    0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 3.13.0-rc8-01969-g4ce63c6 #127
[    0.000000]  00000000 00000000 413fdf08 412710de 413fdf38 4102bb54 4137f43b 00000000
[    0.000000]  00000000 41388b53 000005e7 41093e15 41093e15 415c76e0 4009a000 4e31c810
[    0.000000]  413fdf48 4102bbe7 00000009 00000000 413fdf80 41093e15 4126f38b 00000000
[    0.000000] Call Trace:
[    0.000000]  [<412710de>] dump_stack+0x16/0x18
[    0.000000]  [<4102bb54>] warn_slowpath_common+0x70/0x87
[    0.000000]  [<41093e15>] ? __kmem_cache_create+0x219/0x229
[    0.000000]  [<41093e15>] ? __kmem_cache_create+0x219/0x229
[    0.000000]  [<4102bbe7>] warn_slowpath_null+0x1d/0x1f
[    0.000000]  [<41093e15>] __kmem_cache_create+0x219/0x229
[    0.000000]  [<4126f38b>] ? printk+0x38/0x3a
[    0.000000]  [<415a170f>] create_boot_cache+0x32/0x5d
[    0.000000]  [<415a2663>] kmem_cache_init+0x48/0xd4
[    0.000000]  [<4158c7d3>] start_kernel+0x176/0x329
[    0.000000]  [<4158c493>] ? repair_env_string+0x51/0x51
[    0.000000]  [<4158c2af>] i386_start_kernel+0x79/0x7d
[    0.000000] ---[ end trace db4b7fde7786bb07 ]---
[    0.000000] SLUB: HWalign=128, Order=0-3, MinObjects=0, CPUs=1, Nodes=1

git bisect start 4ce63c662360dbc01efaba87ffadd97378d89a11 7e22e91102c6b9df7c4ae2168910e19d2bb14cd6 --
git bisect good ab99033234a066211c8585e1af5c46951ac4a161  # 18:17     20+      4  Merge 'drm-intel/drm-intel-nightly' into devel-roam-i386-201401140347
git bisect good d35ea44219e64da8dc67362c10b5dbcba7f18b49  # 18:27     20+      5  Merge 'net-next/master' into devel-roam-i386-201401140347
git bisect  bad f822a99c9447a00d7206f1aa013474252a85f190  # 18:33      0-      5  Merge 'slab/slab/next' into devel-roam-i386-201401140347
git bisect good 8afb1474db4701d1ab80cd8251137a3260e6913e  # 18:58     20+      2  slub: Fix calculation of cpu slabs
git bisect  bad 26e4f2057516f1c457e0e95346a00303f983ad53  # 19:08      0-      3  slub: Fix possible format string bug.
git bisect  bad c65c1877bd6826ce0d9713d76e30a7bed8e49f38  # 19:14      0-      7  slub: use lockdep_assert_held
# first bad commit: [c65c1877bd6826ce0d9713d76e30a7bed8e49f38] slub: use lockdep_assert_held
git bisect good 8afb1474db4701d1ab80cd8251137a3260e6913e  # 19:25     60+     13  slub: Fix calculation of cpu slabs
git bisect  bad 4ce63c662360dbc01efaba87ffadd97378d89a11  # 19:25      0-     29  0day head guard for 'devel-roam-i386-201401140347'
git bisect good 73b782c4a36ff1dffbd90123416fed218842d180  # 19:44     60+      8  Revert "slub: use lockdep_assert_held"
git bisect good a6da83f98267bc8ee4e34aa899169991eb0ceb93  # 20:08     60+     14  Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
git bisect  bad cf1c1d193e37b9f79eedddc6bbd71b9f5f9751e5  # 20:17      0-      1  Add linux-next specific files for 20140114

Thanks,
Fengguang