FYI, we noticed the below changes on https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git dev.2015.09.03b commit 92c16ca3910a3f0ea2dfaa58b4f0710854e4d35b ("rcu: Move synchronize_sched_expedited() to combining tree") +---------------------------------------------------------+------------+------------+ | | 0fd0ed1fc6 | 92c16ca391 | +---------------------------------------------------------+------------+------------+ | boot_successes | 25 | 12 | | boot_failures | 0 | 11 | | WARNING:at_kernel/rcu/tree.c:#rcu_report_exp_cpu_mult() | 0 | 10 | | backtrace:acpi_ns_evaluate | 0 | 10 | | backtrace:acpi_ns_init_one_device | 0 | 10 | | backtrace:acpi_initialize_objects | 0 | 10 | | backtrace:acpi_init | 0 | 10 | | backtrace:kernel_init_freeable | 0 | 10 | | BUG:kernel_test_crashed | 0 | 1 | +---------------------------------------------------------+------------+------------+ [ 2.610625] ACPI: Executed 1 blocks of module-level executable AML code [ 2.748380] [Firmware Bug]: ACPI: BIOS _OSI(Linux) query ignored [ 2.755129] ------------[ cut here ]------------ [ 2.760290] WARNING: CPU: 0 PID: 1 at kernel/rcu/tree.c:3558 rcu_report_exp_cpu_mult+0x141/0x160() [ 2.772328] Modules linked in: [ 2.775745] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.2.0-rc1-00088-g92c16ca #1 [ 2.784101] Hardware name: Intel Corporation S2600WTT/S2600WTT, BIOS SE5C610.86B.01.01.0008.021120151325 02/11/2015 [ 2.795752] ffffffff81b77148 ffff88103802b6a8 ffffffff8189a2f5 0000000000000001 [ 2.804039] 0000000000000000 ffff88103802b6e8 ffffffff8107346a ffff88202df38000 [ 2.812328] ffffffff81cfff40 0000ffffffffffff 0000000000000292 0000000000000000 [ 2.820618] Call Trace: [ 2.823351] [<ffffffff8189a2f5>] dump_stack+0x4c/0x65 [ 2.829094] [<ffffffff8107346a>] warn_slowpath_common+0x8a/0xc0 [ 2.835802] [<ffffffff8107355a>] warn_slowpath_null+0x1a/0x20 [ 2.842314] [<ffffffff810d4e41>] rcu_report_exp_cpu_mult+0x141/0x160 [ 2.849499] [<ffffffff810d68aa>] synchronize_sched_expedited+0x38a/0x550 [ 2.857079] [<ffffffff810d6a7e>] synchronize_rcu_expedited+0xe/0x10 [ 2.864170] [<ffffffff8147549b>] acpi_os_map_cleanup+0x14/0x3e [ 2.871460] [<ffffffff81890ebb>] acpi_os_unmap_iomem+0xe4/0xed [ 2.878069] [<ffffffff81890ed2>] acpi_os_unmap_memory+0xe/0x1c [ 2.884675] [<ffffffff8149dfbb>] acpi_ex_system_memory_space_handler+0xe6/0x29d [ 2.892934] [<ffffffff8149ded5>] ? acpi_ex_do_logical_op+0x1b2/0x1b2 [ 2.900120] [<ffffffff81492119>] acpi_ev_address_space_dispatch+0x2d4/0x342 [ 2.907992] [<ffffffff81499a39>] acpi_ex_access_region+0x423/0x4d9 [ 2.914993] [<ffffffff81097a66>] ? __might_sleep+0x56/0xb0 [ 2.921214] [<ffffffff81499ecf>] acpi_ex_field_datum_io+0x183/0x41d [ 2.928300] [<ffffffff8149a41b>] acpi_ex_extract_from_field+0xcf/0x2c3 [ 2.935676] [<ffffffff814990b9>] acpi_ex_read_data_from_field+0x389/0x3da [ 2.943344] [<ffffffff8149e7fe>] acpi_ex_resolve_node_to_value+0x337/0x457 [ 2.951108] [<ffffffff8149ecac>] acpi_ex_resolve_to_value+0x38e/0x42c [ 2.958388] [<ffffffff8148bf49>] acpi_ds_evaluate_name_path+0xa3/0x145 [ 2.965767] [<ffffffff814b5028>] ? acpi_ut_trace_ptr+0x2e/0x78 [ 2.972376] [<ffffffff8148c5d1>] acpi_ds_exec_end_op+0xd6/0x6f8 [ 2.979077] [<ffffffff814ac822>] acpi_ps_parse_loop+0x7b5/0x859 [ 2.985783] [<ffffffff81488fb5>] ? acpi_ds_call_control_method+0x2da/0x2eb [ 2.993547] [<ffffffff814adaca>] acpi_ps_parse_aml+0x1bb/0x4a3 [ 3.000148] [<ffffffff814ae756>] acpi_ps_execute_method+0x276/0x3aa [ 3.007235] [<ffffffff814a5de9>] acpi_ns_evaluate+0x2f6/0x437 [ 3.013739] [<ffffffff814a6412>] acpi_ns_init_one_device+0x17c/0x207 [ 3.020922] [<ffffffff814aa018>] acpi_ns_walk_namespace+0x125/0x276 [ 3.028008] [<ffffffff814a6296>] ? acpi_ns_init_one_object+0x107/0x107 [ 3.035385] [<ffffffff81eb04c8>] ? acpi_sleep_proc_init+0x2a/0x2a [ 3.042277] [<ffffffff814a67fa>] acpi_ns_initialize_devices+0x13e/0x217 [ 3.049760] [<ffffffff81eb2430>] acpi_initialize_objects+0x156/0x1ae [ 3.056952] [<ffffffff81eb055a>] acpi_init+0x92/0x276 [ 3.062682] [<ffffffff81eb04c8>] ? acpi_sleep_proc_init+0x2a/0x2a [ 3.069577] [<ffffffff81002123>] do_one_initcall+0xb3/0x1d0 [ 3.075896] [<ffffffff81e65170>] kernel_init_freeable+0x1c9/0x256 [ 3.082789] [<ffffffff8188d890>] ? rest_init+0x80/0x80 [ 3.088615] [<ffffffff8188d89e>] kernel_init+0xe/0xe0 [ 3.094346] [<ffffffff818a22df>] ret_from_fork+0x3f/0x70 [ 3.100373] [<ffffffff8188d890>] ? rest_init+0x80/0x80 [ 3.106201] ---[ end trace fde73dd3fbbe2b1c ]--- [ 3.111362] ------------[ cut here ]------------ To reproduce: git clone git://git.kernel.org/pub/scm/linux/kernel/git/wfg/lkp-tests.git cd lkp-tests bin/lkp install job.yaml # job file is attached in this email bin/lkp run job.yaml Thanks, Ying Huang