Greetings, 0day kernel testing robot got the below dmesg and the first bad commit is git://git.infradead.org/users/willy/linux-dax.git waiter-diet commit 32a8118b39b6bf2dad19bac66442e1d6a99fa4b6 Author: Matthew Wilcox <mawilcox(a)microsoft.com&gt; AuthorDate: Fri Feb 10 22:35:12 2017 -0500 Commit: Matthew Wilcox <mawilcox(a)microsoft.com&gt; CommitDate: Fri Feb 10 22:35:12 2017 -0500 Shrink mutex by one pointer Instead of embedding a list_head in the mutex, store a pointer to the first waiter. The waiters continue to be linked to each other through a list_head, allowing for O(1) deletion from the middle, removal from the beginning and addition to the end. struct file shrinks by 8 bytes, as does struct device, and struct cgroup. The superblock shrinks by 16 bytes because it has two mutexes. Signed-off-by: Matthew Wilcox <mawilcox(a)microsoft.com&gt; +--------------------------------------------------------------------------+------------+------------+------------+ | | 54b4bd3f9f | 32a8118b39 | 5a5778a8f7 | +--------------------------------------------------------------------------+------------+------------+------------+ | boot_successes | 82 | 0 | 0 | | boot_failures | 662 | 194 | 29 | | INFO:task_blocked_for_more_than#seconds | 222 | 10 | 4 | | Kernel_panic-not_syncing:hung_task:blocked_tasks | 220 | 10 | 1 | | calltrace:SyS_mprotect | 3 | | | | BUG:kernel_reboot-without-warning_in_test_stage | 2 | | | | calltrace:SyS_munmap | 1 | | | | invoked_oom-killer:gfp_mask=0x | 2 | | | | Mem-Info | 2 | | | | page_allocation_failure:order:#,mode:#(GFP_KERNEL|__GFP_NORETRY) | 1 | | | | calltrace:SyS_sethostname | 1 | | | | BUG:kernel_hang_in_test_stage | 1 | 2 | 4 | | Kernel_panic-not_syncing:Attempted_to_kill_init!exitcode= | 436 | 115 | 4 | | WARNING:at_kernel/locking/mutex-debug.c:#debug_mutex_wake_waiter | 0 | 64 | 20 | | BUG:unable_to_handle_kernel | 0 | 64 | 19 | | Oops | 0 | 64 | 20 | | Kernel_panic-not_syncing:Fatal_exception | 0 | 67 | 20 | | BUG:sleeping_function_called_from_invalid_context_at_arch/x86/mm/fault.c | 0 | 34 | 11 | | INFO:lockdep_is_turned_off | 0 | 34 | 11 | | kernel_BUG_at_lib/list_debug.c | 0 | 3 | | | invalid_opcode:#[##]SMP | 0 | 3 | | | WARNING:at_kernel/sched/sched.h:#assert_clock_updated | 0 | 0 | 6 | +--------------------------------------------------------------------------+------------+------------+------------+ Please wait: booting... Starting udev [ 2.581193] ------------[ cut here ]------------ [ 2.582206] WARNING: CPU: 0 PID: 362 at kernel/locking/mutex-debug.c:42 debug_mutex_wake_waiter+0x249/0x250 [ 2.584253] DEBUG_LOCKS_WARN_ON(list_empty(&waiter->list)) [ 2.584255] Modules linked in: [ 2.585673] CPU: 0 PID: 362 Comm: udevd Not tainted 4.10.0-rc5-00370-g32a8118 #2 [ 2.586833] Call Trace: [ 2.587244] show_stack+0x6a/0x6c [ 2.587772] dump_stack+0xc5/0x128 [ 2.588319] ? debug_mutex_wake_waiter+0x249/0x250 git bisect start 5a5778a8f7c3f71ab4515a3f22ec1c046edfe929 d5adbfcd5f7bcc6fa58a41c5c5ada0e5c826ce2c -- git bisect bad c851a34706e18df7364b853b7aa0954d65883c99 # 14:34 14- 21 Merge 'linux-review/Scott-Bauer/uapi-sed-opal-fix-IOW-for-activate-lsp-to-use-correct-struct/20170211-024911' into devel-spot-201702111217 git bisect bad 36b01a3b87bfa85ad341ae93e226abf35e03f567 # 14:57 28- 37 Merge 'linux-review/Christophe-JAILLET/serial-efm32-Fix-parity-management-in-efm32_uart_console_get_options/20170211-054812' into devel-spot-201702111217 git bisect bad e97007f9a376a6c56286a2a59804644d85a3915d # 15:17 32- 34 Merge 'linux-review/Nathan-Fontenot/ibmvnic-Initialize-completion-variables-before-starting-work/20170211-075936' into devel-spot-201702111217 git bisect bad 41acc5df7e90c4a1d0a2411d3863ec91397afd79 # 15:40 2- 37 Merge 'btrfs/for-linus-4.10' into devel-spot-201702111217 git bisect bad 99d50a786610bd9ca97ebe65ee03fdb7eafc107b # 16:00 12- 17 Merge 'linux-review/yuan-linyu/net-remove-member-max-of-struct-scm_fp_list/20170211-114932' into devel-spot-201702111217 git bisect good 8e15883fed03308c8ef04d36ffd8a86f99c4bb24 # 16:21 182+ 99 0day base guard for 'devel-spot-201702111217' git bisect bad 11580e4780c00534ebc3f10daf310740c7392d9e # 16:41 36- 70 Merge 'dax/waiter-diet' into devel-spot-201702111217 git bisect good 54b4bd3f9ff6594858117794724debcc3b789324 # 17:03 190+ 163 Shrink semaphore by one pointer git bisect bad 32a8118b39b6bf2dad19bac66442e1d6a99fa4b6 # 17:18 29- 42 Shrink mutex by one pointer # first bad commit: [32a8118b39b6bf2dad19bac66442e1d6a99fa4b6] Shrink mutex by one pointer git bisect good 54b4bd3f9ff6594858117794724debcc3b789324 # 17:31 543+ 655 Shrink semaphore by one pointer # extra tests with CONFIG_DEBUG_INFO_REDUCED git bisect bad 32a8118b39b6bf2dad19bac66442e1d6a99fa4b6 # 17:56 0- 17 Shrink mutex by one pointer # extra tests on HEAD of linux-devel/devel-spot-201702111217 git bisect bad 5a5778a8f7c3f71ab4515a3f22ec1c046edfe929 # 17:56 0- 29 0day head guard for 'devel-spot-201702111217' # extra tests on tree/branch dax/waiter-diet git bisect bad 32a8118b39b6bf2dad19bac66442e1d6a99fa4b6 # 17:56 0- 194 Shrink mutex by one pointer # extra tests with first bad commit reverted git bisect good 45dae970bcf69879d60d7a4f9724011bc59487ac # 18:23 540+ 509 Revert "Shrink mutex by one pointer" # extra tests on tree/branch linus/master git bisect good 1ee18329fae936089c6c599250ae92482ff2b81f # 18:58 550+ 315 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net # extra tests on tree/branch linux-next/master git bisect good 632571b1bee00494aef749512d9f3290dfba0ead # 19:43 550+ 474 Add linux-next specific files for 20170210 --- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/pipermail/lkp Intel Corporation