FYI, we noticed the below changes on https://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.4.y-rt commit ecfea7087396e8d4d38225296e971af4ada316a2 ("mm: page_alloc: rt-friendly per-cpu pages") +----------------------------------------------------------------+------------+------------+ | | a87bd6aded | ecfea70873 | +----------------------------------------------------------------+------------+------------+ | boot_successes | 81 | 0 | | boot_failures | 42 | 70 | | INFO:possible_irq_lock_inversion_dependency_detected | 39 | 34 | | backtrace:_do_fork | 39 | 46 | | backtrace:do_mount | 32 | 34 | | backtrace:SyS_mount | 32 | 34 | | backtrace:cgroup_setup_root | 39 | 34 | | backtrace:cgroup_init | 39 | 34 | | backtrace:smpboot_thread_fn | 39 | 33 | | backtrace:user_path_at_empty | 6 | | | backtrace:SyS_name_to_handle_at | 6 | | | BUG:unable_to_handle_kernel | 3 | 3 | | Oops | 3 | 3 | | RIP:__lock_acquire | 3 | 3 | | Kernel_panic-not_syncing:Fatal_exception | 3 | 3 | | backtrace:fd_timer_workfn | 3 | 3 | | backtrace:SYSC_mkdirat | 1 | | | backtrace:SyS_mkdir | 1 | | | BUG:using_smp_processor_id()in_preemptible[##]code:kworker/u4 | 0 | 53 | | backtrace:call_usermodehelper_exec_work | 0 | 45 | | backtrace:pgd_alloc | 0 | 34 | | backtrace:mm_init | 0 | 34 | | BUG:using_smp_processor_id()in_preemptible[##]code:kworker/u8 | 0 | 8 | | BUG:using_smp_processor_id()in_preemptible[##]code:kworker/u32 | 0 | 4 | | backtrace:vfs_read | 0 | 1 | | backtrace:SyS_read | 0 | 1 | | BUG:using_smp_processor_id()in_preemptible[##]code:kworker/u64 | 0 | 4 | | backtrace:debug_smp_processor_id | 0 | 2 | | inconsistent{HARDIRQ-ON-W}->{IN-HARDIRQ-W}usage | 0 | 1 | | backtrace:cpu_startup_entry | 0 | 1 | +----------------------------------------------------------------+------------+------------+ [ 23.717099] systemd-sysv-generator[619]: Ignoring K02urandom symlink in rc6.d, not generating urandom.service. [ 23.717107] systemd-sysv-generator[619]: Ignoring K07hwclock.sh symlink in rc6.d, not generating hwclock.service. [ 23.717115] systemd-sysv-generator[619]: Ignoring K01watchdog symlink in rc6.d, not generating watchdog.service. [ 24.405406] BUG: using smp_processor_id() in preemptible [00000000 00000000] code: kworker/u64:0/6 [ 24.405413] caller is debug_smp_processor_id+0x17/0x19 [ 24.405416] CPU: 0 PID: 6 Comm: kworker/u64:0 Not tainted 4.4.0-rc6-00060-gecfea70 #2 [ 24.405418] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Debian-1.8.2-1 04/01/2014 [ 24.405425] Workqueue: events_unbound call_usermodehelper_exec_work [ 24.405429] 0000000000000000 ffff880247553a18 ffffffff8173deed 0000000000000000 [ 24.405431] ffff880247553a48 ffffffff8176207c 0000000000000006 ffff88025eef7f80 [ 24.405434] ffff880247553b48 0000000000000957 ffff880247553a58 ffffffff817620a8 [ 24.405435] Call Trace: [ 24.405441] [] dump_stack+0x4e/0x79 [ 24.405443] [] check_preemption_disabled+0x119/0x12e [ 24.405445] [] debug_smp_processor_id+0x17/0x19 [ 24.405452] [] get_page_from_freelist+0x441/0x7f9 [ 24.405454] [] ? cpumask_next_and+0x16/0x48 [ 24.405461] [] ? ___might_sleep+0xce/0x217 [ 24.405463] [] __alloc_pages_nodemask+0x160/0x2d3 [ 24.405466] [] __alloc_pages_node+0x62/0x69 [ 24.405468] [] alloc_kmem_pages_node+0x1a/0x1c [ 24.405472] [] copy_process+0x163/0x195f [ 24.405474] [] ? call_usermodehelper+0x45/0x45 [ 24.405479] [] ? mark_lock+0x24/0x201 [ 24.405481] [] ? __lock_acquire+0x65b/0xdee [ 24.405483] [] _do_fork+0x82/0x2f7 [ 24.405485] [] ? lock_acquire+0x106/0x192 [ 24.405487] [] ? lock_acquire+0x106/0x192 [ 24.405489] [] kernel_thread+0x29/0x2b [ 24.405491] [] call_usermodehelper_exec_work+0x7d/0x90 [ 24.405497] [] process_one_work+0x247/0x47c [ 24.405500] [] worker_thread+0x1f5/0x2a7 [ 24.405501] [] ? rescuer_thread+0x289/0x289 [ 24.405505] [] kthread+0xc5/0xcd [ 24.405508] [] ? kthread_parkme+0x24/0x24 [ 24.405511] [] ret_from_fork+0x3f/0x70 [ 24.405513] [] ? kthread_parkme+0x24/0x24 [ 24.406071] BUG: using smp_processor_id() in preemptible [00000000 00000000] code: kworker/u64:0/627 [ 24.406077] caller is debug_smp_processor_id+0x17/0x19 [ 24.406080] CPU: 2 PID: 627 Comm: kworker/u64:0 Not tainted 4.4.0-rc6-00060-gecfea70 #2 [ 24.406082] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Debian-1.8.2-1 04/01/2014 [ 24.406086] 0000000000000000 ffff880217dffc70 ffffffff8173deed 0000000000000002 [ 24.406088] ffff880217dffca0 ffffffff8176207c 0000000000000273 ffff88025eef7f80 [ 24.406091] ffff880217dffda0 0000000000000957 ffff880217dffcb0 ffffffff817620a8 [ 24.406092] Call Trace: [ 24.406099] [] dump_stack+0x4e/0x79 [ 24.406101] [] check_preemption_disabled+0x119/0x12e [ 24.406103] [] debug_smp_processor_id+0x17/0x19 [ 24.406110] [] get_page_from_freelist+0x2bd/0x7f9 [ 24.406116] [] ? ___might_sleep+0xce/0x217 [ 24.406119] [] __alloc_pages_nodemask+0x160/0x2d3 [ 24.406124] [] alloc_pages_current+0xae/0xe2 [ 24.406127] [] __get_free_pages+0x16/0x52 [ 24.406132] [] pgd_alloc+0x1d/0xcb [ 24.406137] [] mm_init+0x181/0x1c1 [ 24.406139] [] mm_alloc+0x3f/0x41 [ 24.406143] [] do_execveat_common+0x26b/0x6db [ 24.406145] [] do_execve+0x23/0x25 [ 24.406149] [] call_usermodehelper_exec_async+0x100/0x12d [ 24.406151] [] ? call_usermodehelper+0x45/0x45 [ 24.406155] [] ret_from_fork+0x3f/0x70 [ 24.406157] [] ? call_usermodehelper+0x45/0x45 [ 24.406211] BUG: using smp_processor_id() in preemptible [00000000 00000000] code: kworker/u64:0/627 [ 24.406212] caller is debug_smp_processor_id+0x17/0x19 [ 24.406214] CPU: 2 PID: 627 Comm: kworker/u64:0 Not tainted 4.4.0-rc6-00060-gecfea70 #2 [ 24.406215] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Debian-1.8.2-1 04/01/2014 [ 24.406217] 0000000000000000 ffff880217dffa58 ffffffff8173deed 0000000000000002 [ 24.406220] ffff880217dffa88 ffffffff8176207c 0000000000000273 ffff88025eef7f80 [ 24.406222] ffff880217dffb88 0000000000000957 ffff880217dffa98 ffffffff817620a8 [ 24.406223] Call Trace: [ 24.406225] [] dump_stack+0x4e/0x79 [ 24.406227] [] check_preemption_disabled+0x119/0x12e [ 24.406229] [] debug_smp_processor_id+0x17/0x19 [ 24.406231] [] get_page_from_freelist+0x2bd/0x7f9 [ 24.406234] [] ? ___might_sleep+0xce/0x217 [ 24.406236] [] __alloc_pages_nodemask+0x160/0x2d3 [ 24.406238] [] alloc_pages_current+0xae/0xe2 [ 24.406241] [] __get_free_pages+0x16/0x52 [ 24.406242] [] get_zeroed_page+0x16/0x18 [ 24.406250] [] __pud_alloc+0x20/0xa3 [ 24.406252] [] pud_alloc+0x25/0x30 [ 24.406255] [] handle_mm_fault+0xa7/0xbf1 [ 24.406262] [] ? touch_atime+0x97/0xa0 [ 24.406265] [] ? follow_page_mask+0x490/0x4be [ 24.406269] [] ? lock_is_held+0x49/0x50 [ 24.406271] [] __get_user_pages+0x4bb/0x568 [ 24.406273] [] ? __lock_acquire+0x65b/0xdee [ 24.406275] [] get_user_pages+0x42/0x44 [ 24.406282] [] copy_strings+0x189/0x2b9 [ 24.406284] [] copy_strings_kernel+0x34/0x40 [ 24.406286] [] do_execveat_common+0x3f3/0x6db [ 24.406288] [] do_execve+0x23/0x25 [ 24.406290] [] call_usermodehelper_exec_async+0x100/0x12d [ 24.406292] [] ? call_usermodehelper+0x45/0x45 [ 24.406293] [] ret_from_fork+0x3f/0x70 [ 24.406295] [] ? call_usermodehelper+0x45/0x45 [ 24.406304] BUG: using smp_processor_id() in preemptible [00000000 00000000] code: kworker/u64:0/627 [ 24.406305] caller is debug_smp_processor_id+0x17/0x19 [ 24.406307] CPU: 2 PID: 627 Comm: kworker/u64:0 Not tainted 4.4.0-rc6-00060-gecfea70 #2 [ 24.406308] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Debian-1.8.2-1 04/01/2014 [ 24.406310] 0000000000000000 ffff880217dffa70 ffffffff8173deed 0000000000000002 [ 24.406313] ffff880217dffaa0 ffffffff8176207c 0000000000000273 ffff88025eef7f80 [ 24.406315] ffff880217dffba0 0000000000000957 ffff880217dffab0 ffffffff817620a8 [ 24.406316] Call Trace: [ 24.406318] [] dump_stack+0x4e/0x79 [ 24.406319] [] check_preemption_disabled+0x119/0x12e [ 24.406321] [] debug_smp_processor_id+0x17/0x19 [ 24.406323] [] get_page_from_freelist+0x2bd/0x7f9 [ 24.406326] [] ? ___might_sleep+0xce/0x217 [ 24.406328] [] __alloc_pages_nodemask+0x160/0x2d3 [ 24.406331] [] alloc_pages_current+0xae/0xe2 [ 24.406333] [] __pmd_alloc+0x24/0x161 [ 24.406335] [] pmd_alloc+0x25/0x30 [ 24.406337] [] handle_mm_fault+0xbf/0xbf1 [ 24.406339] [] ? touch_atime+0x97/0xa0 [ 24.406341] [] ? follow_page_mask+0x490/0x4be [ 24.406343] [] ? lock_is_held+0x49/0x50 [ 24.406345] [] __get_user_pages+0x4bb/0x568 [ 24.406347] [] ? __lock_acquire+0x65b/0xdee [ 24.406349] [] get_user_pages+0x42/0x44 [ 24.406351] [] copy_strings+0x189/0x2b9 [ 24.406354] [] copy_strings_kernel+0x34/0x40 [ 24.406356] [] do_execveat_common+0x3f3/0x6db [ 24.406357] [] do_execve+0x23/0x25 [ 24.406359] [] call_usermodehelper_exec_async+0x100/0x12d [ 24.406361] [] ? call_usermodehelper+0x45/0x45 [ 24.406363] [] ret_from_fork+0x3f/0x70 [ 24.406365] [] ? call_usermodehelper+0x45/0x45 [ 24.406374] BUG: using smp_processor_id() in preemptible [00000000 00000000] code: kworker/u64:0/627 [ 24.406376] caller is debug_smp_processor_id+0x17/0x19 [ 24.406377] CPU: 2 PID: 627 Comm: kworker/u64:0 Not tainted 4.4.0-rc6-00060-gecfea70 #2 [ 24.406379] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Debian-1.8.2-1 04/01/2014 [ 24.406381] 0000000000000000 ffff880217dffa80 ffffffff8173deed 0000000000000002 [ 24.406384] ffff880217dffab0 ffffffff8176207c 0000000000000273 ffff88025eef7f80 [ 24.406386] ffff880217dffbb0 0000000000000957 ffff880217dffac0 ffffffff817620a8 [ 24.406387] Call Trace: [ 24.406389] [] dump_stack+0x4e/0x79 [ 24.406391] [] check_preemption_disabled+0x119/0x12e [ 24.406393] [] debug_smp_processor_id+0x17/0x19 [ 24.406395] [] get_page_from_freelist+0x2bd/0x7f9 [ 24.406398] [] ? ___might_sleep+0xce/0x217 [ 24.406400] [] __alloc_pages_nodemask+0x160/0x2d3 [ 24.406403] [] alloc_pages_current+0xae/0xe2 [ 24.406405] [] pte_alloc_one+0x17/0x7b [ 24.406407] [] __pte_alloc+0x1e/0xf1 [ 24.406408] [] handle_mm_fault+0x11d/0xbf1 [ 24.406410] [] ? touch_atime+0x97/0xa0 [ 24.406412] [] ? follow_page_mask+0x490/0x4be [ 24.406414] [] ? lock_is_held+0x49/0x50 [ 24.406416] [] __get_user_pages+0x4bb/0x568 [ 24.406418] [] ? __lock_acquire+0x65b/0xdee [ 24.406420] [] get_user_pages+0x42/0x44 [ 24.406422] [] copy_strings+0x189/0x2b9 [ 24.406425] [] copy_strings_kernel+0x34/0x40 [ 24.406426] [] do_execveat_common+0x3f3/0x6db [ 24.406428] [] do_execve+0x23/0x25 [ 24.406430] [] call_usermodehelper_exec_async+0x100/0x12d [ 24.406432] [] ? call_usermodehelper+0x45/0x45 [ 24.406434] [] ret_from_fork+0x3f/0x70 [ 24.406436] [] ? call_usermodehelper+0x45/0x45 [ 24.406454] BUG: using smp_processor_id() in preemptible [00000000 00000000] code: kworker/u64:0/627 [ 24.406456] caller is debug_smp_processor_id+0x17/0x19 [ 24.406457] CPU: 2 PID: 627 Comm: kworker/u64:0 Not tainted 4.4.0-rc6-00060-gecfea70 #2 [ 24.406459] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Debian-1.8.2-1 04/01/2014 [ 24.406461] 0000000000000000 ffff880217dffaa8 ffffffff8173deed 0000000000000002 [ 24.406464] ffff880217dffad8 ffffffff8176207c 0000000000000273 ffff88025eef7f80 [ 24.406466] ffff880217dffbd8 0000000000000957 ffff880217dffae8 ffffffff817620a8 [ 24.406467] Call Trace: [ 24.406469] [] dump_stack+0x4e/0x79 [ 24.406471] [] check_preemption_disabled+0x119/0x12e [ 24.406473] [] debug_smp_processor_id+0x17/0x19 [ 24.406475] [] get_page_from_freelist+0x2bd/0x7f9 [ 24.406478] [] ? expand_downwards+0x146/0x1d5 [ 24.406480] [] ? ___might_sleep+0xce/0x217 [ 24.406483] [] __alloc_pages_nodemask+0x160/0x2d3 [ 24.406486] [] alloc_pages_vma+0xca/0x108 [ 24.406488] [] handle_mm_fault+0x228/0xbf1 [ 24.406489] [] ? touch_atime+0x97/0xa0 [ 24.406492] [] ? follow_page_mask+0x490/0x4be [ 24.406493] [] ? lock_is_held+0x49/0x50 [ 24.406495] [] __get_user_pages+0x4bb/0x568 [ 24.406497] [] ? __lock_acquire+0x65b/0xdee [ 24.406499] [] get_user_pages+0x42/0x44 [ 24.406501] [] copy_strings+0x189/0x2b9 [ 24.406504] [] copy_strings_kernel+0x34/0x40 [ 24.406506] [] do_execveat_common+0x3f3/0x6db [ 24.406507] [] do_execve+0x23/0x25 [ 24.406510] [] call_usermodehelper_exec_async+0x100/0x12d [ 24.406511] [] ? call_usermodehelper+0x45/0x45 [ 24.406513] [] ret_from_fork+0x3f/0x70 [ 24.406515] [] ? call_usermodehelper+0x45/0x45 [ 24.406621] BUG: using smp_processor_id() in preemptible [00000000 00000000] code: kworker/u64:0/627 [ 24.406623] caller is debug_smp_processor_id+0x17/0x19 [ 24.406625] CPU: 2 PID: 627 Comm: kworker/u64:0 Not tainted 4.4.0-rc6-00060-gecfea70 #2 [ 24.406626] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Debian-1.8.2-1 04/01/2014 [ 24.406629] 0000000000000000 ffff880217dffc28 ffffffff8173deed 0000000000000002 [ 24.406632] ffff880217dffc58 ffffffff8176207c 0000000000000273 0000000000000000 [ 24.406634] ffffea00028d6c28 00000000000bab13 ffff880217dffc68 ffffffff817620a8 [ 24.406635] Call Trace: [ 24.406637] [] dump_stack+0x4e/0x79 [ 24.406639] [] check_preemption_disabled+0x119/0x12e Thanks, Ying Huang