Hi Jason, I got the below dmesg and the first bad commit is git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git core/locking commit 1d8fe7dc8078b23e060ec62ccb4cdc1ac3c41bf8 Author: Jason Low AuthorDate: Tue Jan 28 11:13:14 2014 -0800 Commit: Ingo Molnar CommitDate: Tue Mar 11 12:14:54 2014 +0100 locking/mutexes: Unlock the mutex without the wait_lock +----------------------------------------------------------------------+------------+------------+ | | 1d8fe7dc80 | 221f19a662 | +----------------------------------------------------------------------+------------+------------+ | boot_successes | 2 | 1 | | boot_failures | 18 | 18 | | WARNING:CPU:PID:at_kernel/locking/mutex-debug.c:debug_mutex_unlock() | 18 | 18 | | backtrace:do_fork | 3 | 2 | | backtrace:SyS_clone | 3 | 2 | | backtrace:kobject_add_internal | 1 | | | backtrace:kobject_init_and_add | 1 | | | backtrace:acpi_bus_register_driver | 1 | | | backtrace:acpi_battery_init_async | 1 | | | backtrace:async_run_entry_fn | 1 | | | backtrace:do_execve | 2 | 1 | | backtrace:SyS_execve | 2 | 1 | | backtrace:user_path_at | 1 | | | backtrace:SyS_faccessat | 1 | | | backtrace:SyS_access | 1 | | | backtrace:user_statfs | 1 | 1 | | backtrace:SyS_statfs | 1 | 1 | | backtrace:serio_handle_event | 2 | 2 | | backtrace:vm_mmap_pgoff | 2 | 1 | | backtrace:SyS_mmap_pgoff | 2 | 1 | | backtrace:SyS_mmap | 2 | 1 | | backtrace:do_group_exit | 1 | 4 | | backtrace:SyS_exit_group | 1 | 4 | | backtrace:vfs_stat | 1 | | | backtrace:SyS_newstat | 1 | | | backtrace:mprotect_fixup | 3 | 4 | | backtrace:SyS_mprotect | 3 | 4 | | backtrace:misc_register | 1 | | | backtrace:wafwdt_init | 1 | | | backtrace:kernel_init_freeable | 1 | | +----------------------------------------------------------------------+------------+------------+ [ 5.550712] debug: unmapping init [mem 0xffffffff81c28000-0xffffffff81d5cfff] [ 5.573371] random: init urandom read with 6 bits of entropy available [ 5.636471] ------------[ cut here ]------------ [ 5.637033] WARNING: CPU: 1 PID: 77 at kernel/locking/mutex-debug.c:82 debug_mutex_unlock+0x211/0x220() [ 5.637033] DEBUG_LOCKS_WARN_ON(lock->owner != current) [ 5.637033] Modules linked in: [ 5.637033] CPU: 1 PID: 77 Comm: sh Not tainted 3.14.0-rc6-01849-g221f19a #2 [ 5.637033] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 5.637033] 0000000000000009 ffff8800070bfc98 ffffffff816e5665 ffff8800070bfce0 [ 5.637033] ffff8800070bfcd0 ffffffff8106ad6d ffff88000c86d3a0 0000000000000001 [ 5.637033] 0000000000000246 00000000000000b0 ffff88000c86d300 ffff8800070bfd30 [ 5.637033] Call Trace: [ 5.637033] [] dump_stack+0x4d/0x66 [ 5.637033] [] warn_slowpath_common+0x7d/0xa0 [ 5.637033] [] warn_slowpath_fmt+0x4c/0x50 [ 5.637033] [] debug_mutex_unlock+0x211/0x220 [ 5.637033] [] __mutex_unlock_slowpath+0xdb/0x210 [ 5.637033] [] mutex_unlock+0xe/0x10 [ 5.637033] [] vma_link+0x7f/0xd0 [ 5.637033] [] mmap_region+0x494/0x670 [ 5.637033] [] ? __lock_acquire+0x48e/0xcc0 [ 5.637033] [] do_mmap_pgoff+0x312/0x3e0 [ 5.637033] [] vm_mmap_pgoff+0x90/0xc0 [ 5.637033] [] SyS_mmap_pgoff+0xe7/0x110 [ 5.637033] [] SyS_mmap+0x22/0x30 [ 5.637033] [] system_call_fastpath+0x16/0x1b [ 5.637033] ---[ end trace 926fb1180f642ed0 ]--- [ 5.798610] init: Failed to create pty - disabling logging for job git bisect start 221f19a662f536aa8640694e744019776d2df584 8712a00514e50aafa7c9bf5cd3955fa60758e53b -- git bisect bad 8d8ec3963d9d341ca73b817a931f274807ecc5ae # 15:55 0- 2 Merge branch 'x86/asmlinkage' git bisect bad b4a4183f983cfed78029b7ce9a7b809da742b794 # 16:32 0- 5 Merge branch 'perf/urgent' git bisect bad 319309fdafea7717522b94e406ea3429fd9498b4 # 16:44 0- 2 Merge branch 'core/types' git bisect bad cbdc4aaf1932bbf23934443126f610b64d53e7ce # 17:39 0- 1 manual merge of core/locking git bisect good 47be1c1a0e188232b5e5962917b21750053cd3f8 # 18:09 20+ 0 lockdep: Change lockdep_set_novalidate_class() to use _and_name git bisect good c9122da1e2d29bd6a1475a0d1ce2aa6ac6ea25fa # 18:46 20+ 0 locking: Move mcs_spinlock.h into kernel/locking/ git bisect bad 1d8fe7dc8078b23e060ec62ccb4cdc1ac3c41bf8 # 19:22 0- 9 locking/mutexes: Unlock the mutex without the wait_lock git bisect good 47667fa1502e4d759df87e9cc7fbc0f202483361 # 20:14 20+ 0 locking/mutexes: Modify the way optimistic spinners are queued # first bad commit: [1d8fe7dc8078b23e060ec62ccb4cdc1ac3c41bf8] locking/mutexes: Unlock the mutex without the wait_lock git bisect good 47667fa1502e4d759df87e9cc7fbc0f202483361 # 20:28 60+ 0 locking/mutexes: Modify the way optimistic spinners are queued git bisect bad 221f19a662f536aa8640694e744019776d2df584 # 20:28 0- 18 Merge branch 'tools/kvm' git bisect good 33807f4f0daec3b00565c2932d95f614f5833adf # 21:43 60+ 0 Merge branch 'for-next' of git://git.samba.org/sfrench/cifs-2.6 git bisect good 69d5cdda16b3c9767b82d80b07edb9bb056448e3 # 22:40 60+ 1 Add linux-next specific files for 20140311 git bisect bad 6670a8a6f7e711b45114e6c66871d8bbc22a59ed # 22:41 0- 9 Merge branch 'timers/core' Thanks, Fengguang