FYI, we noticed the following commit: commit: 37a271c8a68547a160e00660759a562273083679 ("linux-next") git://git.cmpxchg.org/linux-mmotm.git master in testcase: locktorture with following parameters: runtime: 300s test-description: This torture test consists of creating a number of kernel threads which acquire the lock and hold it for specific amount of time, thus simulating different critical region behaviors. test-url: https://www.kernel.org/doc/Documentation/locking/locktorture.txt on test machine: qemu-system-x86_64 -enable-kvm -cpu Haswell,+smep,+smap -smp 2 -m 2G caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace): +--------------------------------------------------+------------+------------+ | | 46a7f4ac96 | 37a271c8a6 | +--------------------------------------------------+------------+------------+ | boot_successes | 4 | 0 | | boot_failures | 1 | 14 | | BUG:kernel_reboot-without-warning_in_test_stage | 1 | | | WARNING:at_kernel/sched/sched.h:#set_next_entity | 0 | 6 | | BUG:kernel_hang_in_boot_stage | 0 | 8 | +--------------------------------------------------+------------+------------+ [ 41.886771] WARNING: CPU: 1 PID: 2355 at kernel/sched/sched.h:804 set_next_entity+0x803/0x83f [ 41.888004] rq->clock_update_flags < RQCF_ACT_SKIP [ 41.888004] Modules linked in: locktorture torture iosf_mbi acpi_cpufreq [ 41.888004] CPU: 1 PID: 2355 Comm: torture_shuffle Not tainted 4.10.0-rc6-mm1-00308-g37a271c #1 [ 41.888004] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.3-20161025_171302-gandalf 04/01/2014 [ 41.888004] Call Trace: [ 41.888004] dump_stack+0x86/0xc0 [ 41.888004] __warn+0xc2/0xdd [ 41.888004] warn_slowpath_fmt+0x4b/0x53 [ 41.888004] set_next_entity+0x803/0x83f [ 41.888004] ? enqueue_task_fair+0x12ff/0x132f [ 41.888004] ? kvm_sched_clock_read+0x9/0x12 [ 41.888004] ? sched_clock+0x9/0xd [ 41.888004] set_curr_task_fair+0x26/0x2f [ 41.888004] ? set_curr_task_fair+0x26/0x2f [ 41.888004] do_set_cpus_allowed+0xa3/0xae [ 41.888004] __set_cpus_allowed_ptr+0xaf/0x1ff [ 41.888004] ? torture_onoff+0x1c0/0x1c0 [torture] [ 41.888004] set_cpus_allowed_ptr+0x10/0x12 [ 41.888004] torture_shuffle+0xd3/0x116 [torture] [ 41.888004] kthread+0x12a/0x132 [ 41.888004] ? kthread_create_on_node+0x3f/0x3f [ 41.888004] ? umh_complete+0x25/0x25 [ 41.888004] ? call_usermodehelper_exec_async+0x134/0x13d [ 41.888004] ret_from_fork+0x31/0x40 [ 41.888004] ---[ end trace 5a5cc8cca4e1f6ab ]--- To reproduce: git clone git://git.kernel.org/pub/scm/linux/kernel/git/wfg/lkp-tests.git cd lkp-tests bin/lkp qemu -k <bzImage> job-script # job-script is attached in this email Thanks, Kernel Test Robot