Greeting, FYI, we noticed the following commit (built with gcc-9): commit: 05e46721b33339921f456a3ccd9752f6b7411843 ("mm/swap.c: optimizing __pagevec_lru_add lru_lock") https://github.com/alexshi/linux.git lrunext in testcase: rcuperf with following parameters: runtime: 300s perf_type: srcu on test machine: qemu-system-i386 -enable-kvm -cpu SandyBridge -smp 8 -m 16G caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace): +--------------------------------------------+------------+------------+ | | 34bb09ab41 | 05e46721b3 | +--------------------------------------------+------------+------------+ | boot_successes | 4 | 1 | | boot_failures | 0 | 1 | | BUG:using_smp_processor_id()in_preemptible | 0 | 1 | +--------------------------------------------+------------+------------+ If you fix the issue, kindly add following tag Reported-by: kernel test robot [ 88.523381] BUG: using smp_processor_id() in preemptible [00000000] code: swapper/0/1 [ 88.525627] caller is debug_smp_processor_id+0x12/0x14 [ 88.526995] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 5.8.0-next-20200803-00024-g05e46721b3333 #1 [ 88.529291] Call Trace: [ 88.529900] dump_stack+0x52/0x66 [ 88.530708] check_preemption_disabled+0x92/0xa4 [ 88.531837] debug_smp_processor_id+0x12/0x14 [ 88.532947] __pagevec_lru_add+0x16/0x2c4 [ 88.533915] ? _raw_spin_unlock_irqrestore+0x27/0x3a [ 88.535145] lru_add_drain_cpu+0x1f/0xe6 [ 88.536071] ? drain_pages+0x2e/0x2e [ 88.536943] page_alloc_cpu_dead+0xc/0x20 [ 88.537953] cpuhp_invoke_callback+0xa2/0x20c [ 88.538987] ? drain_pages+0x2e/0x2e [ 88.539848] ? padata_replace+0x81/0x81 [ 88.540807] _cpu_down+0xd3/0x16c [ 88.541670] cpu_down_maps_locked+0x15/0x1d [ 88.542748] cpu_device_down+0x1c/0x29 [ 88.543677] cpu_subsys_offline+0x8/0xa [ 88.544584] device_offline+0x4d/0x74 [ 88.545467] remove_cpu+0x19/0x26 [ 88.546302] _debug_hotplug_cpu+0x22/0x82 [ 88.547321] ? topology_init+0x2b/0x2b [ 88.548276] debug_hotplug_cpu+0xc/0x10 [ 88.549713] do_one_initcall+0x9c/0x1b7 [ 88.550680] ? parse_args+0x15f/0x293 [ 88.551569] ? trace_initcall_level+0x6b/0x6f [ 88.552642] do_initcalls+0xa8/0xc8 [ 88.553463] kernel_init_freeable+0x110/0x13a [ 88.554495] ? rest_init+0xd3/0xd3 [ 88.555319] kernel_init+0x8/0xdf [ 88.556097] ret_from_fork+0x19/0x30 [ 88.558971] DEBUG_HOTPLUG_CPU0: CPU 0 is now offline [ 88.561760] Freeing unused kernel image (initmem) memory: 776K [ 88.668109] Write protecting kernel text and read-only data: 24036k [ 88.669590] NX-protecting the kernel data: 14020k [ 88.671290] rodata_test: all tests were successful [ 88.682260] Run /init as init process [ 88.683059] with arguments: [ 88.683685] /init [ 88.684193] with environment: [ 88.684953] HOME=/ [ 88.685502] TERM=linux [ 88.686209] user=lkp [ 88.686828] job=/lkp/jobs/scheduled/vm-snb-i386-33/rcuperf-srcu-300s-debian-i386-20191205.cgz-05e46721b33339921f456a3ccd9752f6b7411843-20200805-26088-tnk6a5-3.yaml [ 88.690300] ARCH=i386 [ 88.690905] kconfig=i386-randconfig-a013-20200804 [ 88.692040] branch=alexshi/lrunext [ 88.692916] commit=05e46721b33339921f456a3ccd9752f6b7411843 [ 88.698137] BOOT_IMAGE=/pkg/linux/i386-randconfig-a013-20200804/gcc-9/05e46721b33339921f456a3ccd9752f6b7411843/vmlinuz-5.8.0-next-20200803-00024-g05e46721b3333 [ 88.701529] max_uptime=1500 [ 88.702280] RESULT_ROOT=/result/rcuperf/srcu-300s/vm-snb-i386/debian-i386-20191205.cgz/i386-randconfig-a013-20200804/gcc-9/05e46721b33339921f456a3ccd9752f6b7411843/2 [ 88.705693] LKP_SERVER=inn [ 88.706448] selinux=0 [ 88.707062] softlockup_panic=1 [ 88.707841] prompt_ramdisk=0 [ 88.708593] vga=normal [ 88.719222] systemd[1]: RTC configured in localtime, applying delta of 0 minutes to system time. [ 88.721573] systemd[1]: Failed to redirect standard streams to /dev/null: Device or resource busy [ 88.728282] random: systemd: uninitialized urandom read (16 bytes read) [ 88.731183] random: systemd: uninitialized urandom read (16 bytes read) Welcome to Debian GNU/Linux 9 (stretch)! [ 88.755983] process 203 (systemd) attempted a POSIX timer syscall while CONFIG_POSIX_TIMERS is not set [ 88.803861] random: systemd-cryptse: uninitialized urandom read (16 bytes read) [ OK ] Listening on Syslog Socket. [ OK ] Listening on /dev/initctl Compatibility Named Pipe. [ OK ] Listening on Journal Socket (/dev/log). [ OK ] Started Dispatch Password Requests to Console Directory Watch. [ OK ] Reached target Swap. [ OK ] Listening on Journal Socket. [ OK ] Listening on RPCbind Server Activation Socket. [ OK ] Created slice User and Session Slice. [ OK ] Started Forward Password Requests to Wall Directory Watch. [ OK ] Reached target Encrypted Volumes. [ OK ] Reached target Paths. [ OK ] Listening on udev Kernel Socket. [ OK ] Created slice System Slice. [ OK ] Created slice system-serial\x2dgetty.slice. Starting Load Kernel Modules... [ [ 88.917273] random: fast init done OK ] Reached target Slices. Mounting RPC Pipe File System... [ OK ] Created slice system-getty.slice. Starting Remount Root and Kernel File Systems... Starting Journal Service... Starting Create Static Device Nodes in /dev... Mounting Debug File System... [ OK ] Listening on udev Control Socket. [ OK ] Mounted RPC Pipe File System. [ OK ] Mounted Debug File System. [ OK ] Started Load Kernel Modules. [ OK ] Started Remount Root and Kernel File Systems. [ OK ] Started Create Static Device Nodes in /dev. Starting udev Kernel Device Manager... [ OK ] Reached target Local File Systems (Pre). [ OK ] Reached target Local File Systems. Starting Preprocess NFS configuration... Starting Load/Save Random Seed... To reproduce: # build kernel cd linux cp config-5.8.0-next-20200803-00024-g05e46721b3333 .config make HOSTCC=gcc-9 CC=gcc-9 ARCH=i386 olddefconfig prepare modules_prepare bzImage git clone https://github.com/intel/lkp-tests.git cd lkp-tests bin/lkp qemu -k job-script # job-script is attached in this email Thanks, Rong Chen