FYI, we noticed the below changes on git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git rcu/dev commit 4da4e28818f5017c96f0fde72d643e965ac78253 ("Squash with 287f7a10372c (rcu: Process offlining and onlining only at grace-period start)") +----------------------------------------------------------------+------------+------------+ | | 414341d2c2 | 4da4e28818 | +----------------------------------------------------------------+------------+------------+ | boot_successes | 20 | 0 | | early-boot-hang | 1 | | | boot_failures | 0 | 15 | | WARNING:at_kernel/rcu/tree_plugin.h:#rcu_note_context_switch() | 0 | 15 | | backtrace:SYSC_kill | 0 | 1 | | backtrace:SyS_kill | 0 | 1 | +----------------------------------------------------------------+------------+------------+ [ 0.028186] NET: Registered protocol family 16 [ 0.028902] ------------[ cut here ]------------ [ 0.028902] ------------[ cut here ]------------ [ 0.029000] WARNING: CPU: 0 PID: 1 at kernel/rcu/tree_plugin.h:177 rcu_note_context_switch+0x7e/0x139() [ 0.029000] WARNING: CPU: 0 PID: 1 at kernel/rcu/tree_plugin.h:177 rcu_note_context_switch+0x7e/0x139() [ 0.029000] Modules linked in: [ 0.029000] Modules linked in: [ 0.029000] CPU: 0 PID: 1 Comm: swapper Not tainted 3.19.0-07521-g4904fcf #64 [ 0.029000] CPU: 0 PID: 1 Comm: swapper Not tainted 3.19.0-07521-g4904fcf #64 [ 0.029000] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 0.029000] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 0.029000] 00000000 [ 0.029000] 00000000 00000000 00000000 78107d3c 78107d3c 85147a3d 85147a3d 78107d58 78107d58 84e211e8 84e211e8 000000b1 000000b1 84e4d734 84e4d734 [ 0.029000] 853cff40 [ 0.029000] 853cff40 78134ec8 78134ec8 853d0140 853d0140 78107d68 78107d68 84e21263 84e21263 00000009 00000009 00000000 00000000 78107d84 78107d84 [ 0.029000] 84e4d734 [ 0.029000] 84e4d734 7803a000 7803a000 00000246 00000246 78107fec 78107fec 78134ec8 78134ec8 7814d98c 7814d98c 78107da4 78107da4 8514887c 8514887c [ 0.029000] Call Trace: [ 0.029000] Call Trace: [ 0.029000] [<85147a3d>] dump_stack+0x16/0x18 [ 0.029000] [<85147a3d>] dump_stack+0x16/0x18 [ 0.029000] [<84e211e8>] warn_slowpath_common+0x7e/0x95 [ 0.029000] [<84e211e8>] warn_slowpath_common+0x7e/0x95 [ 0.029000] [<84e4d734>] ? rcu_note_context_switch+0x7e/0x139 [ 0.029000] [<84e4d734>] ? rcu_note_context_switch+0x7e/0x139 [ 0.029000] [<84e21263>] warn_slowpath_null+0xf/0x13 [ 0.029000] [<84e21263>] warn_slowpath_null+0xf/0x13 [ 0.029000] [<84e4d734>] rcu_note_context_switch+0x7e/0x139 [ 0.029000] [<84e4d734>] rcu_note_context_switch+0x7e/0x139 [ 0.029000] [<8514887c>] __schedule+0x14/0x50f [ 0.029000] [<8514887c>] __schedule+0x14/0x50f [ 0.029000] [<84e2ed89>] ? insert_work+0x43/0x49 [ 0.029000] [<84e2ed89>] ? insert_work+0x43/0x49 [ 0.029000] [<84e37c82>] preempt_schedule_common+0x19/0x30 [ 0.029000] [<84e37c82>] preempt_schedule_common+0x19/0x30 [ 0.029000] [<85148e8a>] preempt_schedule+0x1e/0x20 [ 0.029000] [<85148e8a>] preempt_schedule+0x1e/0x20 [ 0.029000] [<84f12996>] ___preempt_schedule+0x8/0xc [ 0.029000] [<84f12996>] ___preempt_schedule+0x8/0xc [ 0.029000] [<84e23900>] ? __local_bh_enable_ip+0x72/0x75 [ 0.029000] [<84e23900>] ? __local_bh_enable_ip+0x72/0x75 [ 0.029000] [<8514b76d>] _raw_spin_unlock_bh+0x15/0x17 [ 0.029000] [<8514b76d>] _raw_spin_unlock_bh+0x15/0x17 [ 0.029000] [<84f16aec>] unlock_buckets+0x2f/0x33 [ 0.029000] [<84f16aec>] unlock_buckets+0x2f/0x33 [ 0.029000] [<84f16de1>] rhashtable_lookup_compare_insert+0x9b/0xab [ 0.029000] [<84f16de1>] rhashtable_lookup_compare_insert+0x9b/0xab [ 0.029000] [<85096801>] ? netlink_overrun+0x26/0x32 [ 0.029000] [<85096801>] ? netlink_overrun+0x26/0x32 [ 0.029000] [<85096ece>] netlink_insert+0x58/0x83 [ 0.029000] [<85096ece>] netlink_insert+0x58/0x83 [ 0.029000] [<8509813f>] __netlink_kernel_create+0xe9/0x1c3 [ 0.029000] [<8509813f>] __netlink_kernel_create+0xe9/0x1c3 [ 0.029000] [<8507137f>] rtnetlink_net_init+0x3f/0x5a [ 0.029000] [<8507137f>] rtnetlink_net_init+0x3f/0x5a [ 0.029000] [<85070d35>] ? rtnetlink_net_exit+0x1e/0x1e [ 0.029000] [<85070d35>] ? rtnetlink_net_exit+0x1e/0x1e [ 0.029000] [<85061b2f>] ops_init+0xc9/0xef [ 0.029000] [<85061b2f>] ops_init+0xc9/0xef [ 0.029000] [<85061e19>] register_pernet_operations+0x99/0xf9 [ 0.029000] [<85061e19>] register_pernet_operations+0x99/0xf9 [ 0.029000] [<85061e95>] register_pernet_subsys+0x1c/0x2d [ 0.029000] [<85061e95>] register_pernet_subsys+0x1c/0x2d [ 0.029000] [<854569c0>] rtnetlink_init+0xd/0x144 [ 0.029000] [<854569c0>] rtnetlink_init+0xd/0x144 [ 0.029000] [<85457c24>] netlink_proto_init+0x14e/0x164 [ 0.029000] [<85457c24>] netlink_proto_init+0x14e/0x164 [ 0.029000] [<850966bc>] ? is_vmalloc_addr+0x39/0x39 [ 0.029000] [<850966bc>] ? is_vmalloc_addr+0x39/0x39 [ 0.029000] [<84f1696a>] ? __percpu_ida_init+0xe5/0xe5 [ 0.029000] [<84f1696a>] ? __percpu_ida_init+0xe5/0xe5 [ 0.029000] [<84f16998>] ? rht_grow_above_75+0x2e/0x2e [ 0.029000] [<84f16998>] ? rht_grow_above_75+0x2e/0x2e [ 0.029000] [<85457ad6>] ? init_em_u32+0xf/0xf [ 0.029000] [<85457ad6>] ? init_em_u32+0xf/0xf [ 0.029000] [<84e0049a>] do_one_initcall+0xe8/0x163 [ 0.029000] [<84e0049a>] do_one_initcall+0xe8/0x163 [ 0.029000] [<8542d41e>] ? do_early_param+0x73/0x73 [ 0.029000] [<8542d41e>] ? do_early_param+0x73/0x73 [ 0.029000] [<84e32943>] ? parse_args+0x28c/0x389 [ 0.029000] [<84e32943>] ? parse_args+0x28c/0x389 [ 0.029000] [<8542d41e>] ? do_early_param+0x73/0x73 [ 0.029000] [<8542d41e>] ? do_early_param+0x73/0x73 [ 0.029000] [<8542db12>] kernel_init_freeable+0xd6/0x14e [ 0.029000] [<8542db12>] kernel_init_freeable+0xd6/0x14e [ 0.029000] [<8542db12>] ? kernel_init_freeable+0xd6/0x14e [ 0.029000] [<8542db12>] ? kernel_init_freeable+0xd6/0x14e [ 0.029000] [<8514628c>] kernel_init+0x8/0xb0 [ 0.029000] [<8514628c>] kernel_init+0x8/0xb0 [ 0.029000] [<8514ba80>] ret_from_kernel_thread+0x20/0x30 [ 0.029000] [<8514ba80>] ret_from_kernel_thread+0x20/0x30 [ 0.029000] [<85146284>] ? rest_init+0x6f/0x6f [ 0.029000] [<85146284>] ? rest_init+0x6f/0x6f [ 0.029000] ---[ end trace b93b19f720f08f2d ]--- [ 0.029000] ---[ end trace b93b19f720f08f2d ]--- Thanks, Ying Huang