Tejun, Here is another bisect. The first bad commit could be any of: 5a87728c4502d0a99f53346545605360fce1e91e cgroup: factor out cgroup_setup_root() from cgroup_mount() 6a9fc7f859a24754999ff9096015583b70dfa162 cgroup: update cgroup name handling bb7a2fa01329b0afc2307011d634c4bde5ef10f1 cgroup: restructure locking and error handling in cgroup_mount() 0571b870aa584093000cc9a2925db1463813212f cgroup: make cgroup_subsys->base_cftypes use cgroup_add_cftypes() 4e6a3a2aae35039751d88a567a0346660f01a1a1 cgroup: release cgroup_mutex over file removals 43b48e8041f0bfaf295e796d9157b40dfac798f0 cgroup: update the meaning of cftype->max_write_len 9c92986924852946840aa265c66325790e926a36 cgroup: introduce cgroup_tree_mutex 0be500347039f5ef658fd3045ca42afa72583e2d cgroup: improve css_from_dir() into css_tryget_from_dir() ed6d28fc60daadf1f445ab439e4da86fd363f2bb cgroup: introduce cgroup_init/exit_cftypes() 80f9567b80a645d67f332bc6707ac4d859f05e19 Merge branch 'review-kernfs-cgroup-prep' into review-kernfs-conversion c48b4c28016fdf927148616940279291d028cbc2 cgroup: introduce cgroup_ino() 455447a2486bc982c7aae2bb0cf93c810da5faae cgroup: misc preps for kernfs conversion 7bac9560a270d2fca5b65893851aa29676db2f4e kernfs: add CONFIG_KERNFS 8d4bee55479f18cbbcbdd3a1c9a3331b90932f05 cgroup: relocate functions in preparation of kernfs conversion ad1521d8543336ac7acf14f918f467ec27e765b9 kernfs: implement kernfs_get_parent(), kernfs_name/path() and friends 7c87a9de3197667e64401fdba77cb641b93d9d90 cgroup: convert to kernfs We cannot bisect more! +------------------------------------------------------------+----+ | | | +------------------------------------------------------------+----+ | boot_successes | 0 | | boot_failures | 19 | | BUG:unable_to_handle_kernel_NULL_pointer_dereference_at | 19 | | Oops:SMP_DEBUG_PAGEALLOC | 19 | | RIP:kobject_add_internal | 19 | | WARNING:CPU:PID:at_kernel/smp.c:smp_call_function_single() | 19 | | Kernel_panic-not_syncing:Attempted_to_kill_init_exitcode= | 19 | | backtrace:__class_register | 10 | | backtrace:netdev_kobject_init | 10 | | backtrace:net_dev_init | 10 | | backtrace:kernel_init_freeable | 10 | +------------------------------------------------------------+----+ [ 0.413902] PCI: pci_cache_line_size set to 64 bytes [ 0.415027] e820: reserve RAM buffer [mem 0x0009fc00-0x0009ffff] [ 0.416023] e820: reserve RAM buffer [mem 0x0fffe000-0x0fffffff] [ 0.417267] BUG: unable to handle kernel NULL pointer dereference at 0000000000000080 [ 0.418531] IP: [] kobject_add_internal+0x720/0x940 [ 0.419632] PGD 0 [ 0.419998] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC [ 0.420000] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.14.0-rc1-wl-ath-00981-g4f030e0 #2 [ 0.420000] task: ffff88000035c010 ti: ffff88000035e000 task.ti: ffff88000035e000 [ 0.420000] RIP: 0010:[] [] kobject_add_internal+0x720/0x940 [ 0.420000] RSP: 0000:ffff88000035fdb8 EFLAGS: 00010202 [ 0.420000] RAX: 0000000000000001 RBX: ffff88000dc6ec48 RCX: 0000000000000001 [ 0.420000] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff82df90f8 [ 0.420000] RBP: ffff88000035fde8 R08: 0000000000000001 R09: 0000000000000000 [ 0.420000] R10: ffffffff81436fa0 R11: ffffffff826015a1 R12: 0000000000000000 [ 0.420000] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 0.420000] FS: 0000000000000000(0000) GS:ffff88000f800000(0000) knlGS:0000000000000000 [ 0.420000] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 0.420000] CR2: 0000000000000080 CR3: 000000000280b000 CR4: 00000000000006f0 [ 0.420000] Stack: [ 0.420000] ffffffff8117d402 ffff88000dc6ec48 ffff88000dc6ec00 ffffffff83c0fae8 [ 0.420000] 0000000000000000 0000000000000000 ffff88000035fe08 ffffffff81437958 [ 0.420000] ffffffff82d0dec0 ffff88000dc6ec00 ffff88000035fe38 ffffffff8190473f [ 0.420000] Call Trace: [ 0.420000] [] ? __raw_spin_lock_init+0x42/0x70 [ 0.420000] [] kset_register+0x38/0x80 [ 0.420000] [] __class_register+0x1cf/0x390 [ 0.420000] [] ? netdev_init+0x9a/0x9a [ 0.420000] [] netdev_kobject_init+0x31/0x3a [ 0.420000] [] net_dev_init+0x77/0x292 [ 0.420000] [] ? netdev_init+0x9a/0x9a [ 0.420000] [] do_one_initcall+0x14f/0x27b [ 0.420000] [] ? parameq+0x17/0xc0 [ 0.420000] [] ? parse_args+0x315/0x660 [ 0.420000] [] kernel_init_freeable+0x311/0x404 [ 0.420000] [] ? do_early_param+0xd7/0xd7 [ 0.420000] [] ? rest_init+0x140/0x140 [ 0.420000] [] kernel_init+0x16/0x1e0 [ 0.420000] [] ret_from_fork+0x7c/0xb0 [ 0.420000] [] ? rest_init+0x140/0x140 [ 0.420000] Code: ff e9 33 fe ff ff b8 fe ff ff ff e9 29 fe ff ff 48 83 05 b3 1c 42 02 01 48 c7 c7 f8 90 df 82 4c 8b 63 30 48 83 05 60 16 42 02 01 <41> 0f b7 84 24 80 00 00 00 83 e0 0f 66 83 e8 01 41 0f 95 c5 31 [ 0.420000] RIP [] kobject_add_internal+0x720/0x940 [ 0.420000] RSP [ 0.420000] CR2: 0000000000000080 [ 0.420000] ---[ end trace ec833e17e878915c ]--- [ 0.420000] swapper/0 (1) used greatest stack depth: 4760 bytes left git bisect start 4f030e0534a17070336d1d1e12698da355c344b0 38dbfb59d1175ef458d006556061adeaa8751b72 -- git bisect good 59ad03776650d10cf461d6cdf32e3716baa9ffda # 17:04 20+ 20 Merge 'mac80211-next/master' into devel-hourly-2014020518 git bisect bad bf541a8b7b445952193b3f25f70158804032b3d4 # 17:21 0- 6 Merge 'usb/usb-linus' into devel-hourly-2014020518 git bisect good 5fd14ed3636ec4bccf69003079c64556660cff1c # 18:02 20+ 20 Merge 'stericsson/ux500-devicetree-cleanup' into devel-hourly-2014020518 git bisect good 8a9b207c1dc7eebc51981b036e60d04153e3233f # 18:29 20+ 20 Merge 'arm-perf/cacheflush' into devel-hourly-2014020518 git bisect bad 16f9c9e4362d02b34cfce98346a0667f6bfb0db1 # 18:59 0- 1 Merge 'asoc/for-next' into devel-hourly-2014020518 git bisect bad 52cef3770aefaf7b8d39ea53423533e50286a774 # 19:08 0- 8 Merge 'cgroup/review-post-kernfs-conversion' into devel-hourly-2014020518 git bisect good 7911ad279cf6b3311cfbe44ac437f2b9d5c4318a # 20:41 20+ 20 sysfs, driver-core: remove unused {sysfs|device}_schedule_callback_owner() git bisect good 36b08489bf55244735cd2f85fedd368434982c14 # 21:52 20+ 20 kernfs: rename kernfs_dir_ops to kernfs_syscall_ops git bisect good 9b9fbc2cbda740628f415261e28aed5fecb6f754 # 22:47 20+ 20 kernfs: allow nodes to be created in the deactivated state git bisect bad 0f23a4ecfbef2a707ddfd9d8359ae5220c8d76c1 # 23:58 0- 20 cgroup: remove cgroup->name git bisect bad 044c79a581aa54cd9ba306f74d92fda6621a8ec1 # 00:45 0- 6 cgroup: remove cftype_set git bisect good 246bc9304252810e16bd02358c3e6928a74c8f62 # 01:51 20+ 20 kernfs: implement kernfs_node_from_dentry(), kernfs_root_from_sb() and kernfs_rename() git bisect bad 7c87a9de3197667e64401fdba77cb641b93d9d90 # 02:38 0- 20 cgroup: convert to kernfs git bisect good ef42c58a5b4b8060a3931aab36bf2b4f81b44afc # 04:10 20+ 20 Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip git bisect good 0cc2aa51be9d2f2b001c0e070b2e5cdde89b39f4 # 04:37 20+ 20 Add linux-next specific files for 20140206 Thanks, Fengguang