FYI, we noticed the following commit (built with gcc-7): commit: ac1f97be8df98718a3d545cb6bb6ee4159e4300c ("sched/fair: Add trivial fair server") https://kernel.googlesource.com/pub/scm/linux/kernel/git/peterz/queue.git sched/wip-deadline in testcase: boot on test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 4G caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace): +---------------------------------------------------------+------------+------------+ | | f4fa60e1b1 | ac1f97be8d | +---------------------------------------------------------+------------+------------+ | boot_successes | 5 | 0 | | boot_failures | 6 | 14 | | BUG:kernel_reboot-without-warning_in_test_stage | 6 | | | WARNING:at_kernel/sched/sched.h:#dl_server_init | 0 | 14 | | RIP:dl_server_init | 0 | 14 | | WARNING:at_kernel/sched/deadline.c:#task_non_contending | 0 | 3 | | RIP:task_non_contending | 0 | 3 | | kernel_BUG_at_kernel/sched/deadline.c | 0 | 3 | | invalid_opcode:#[##] | 0 | 3 | | RIP:enqueue_dl_entity | 0 | 3 | | RIP:default_idle | 0 | 2 | | Kernel_panic-not_syncing:Fatal_exception_in_interrupt | 0 | 2 | | Kernel_panic-not_syncing:Fatal_exception | 0 | 1 | +---------------------------------------------------------+------------+------------+ If you fix the issue, kindly add following tag Reported-by: kernel test robot <lkp(a)intel.com&gt; [ 3.215886] WARNING: CPU: 0 PID: 0 at kernel/sched/sched.h:1108 dl_server_init+0x68/0xca [ 3.237973] Modules linked in: [ 3.242573] CPU: 0 PID: 0 Comm: swapper Not tainted 5.3.0-rc1-00388-gac1f97be8df987 #4 [ 3.254600] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 [ 3.267232] RIP: 0010:dl_server_init+0x68/0xca [ 3.274057] Code: 0b 83 bd 20 0a 00 00 01 4c 8b 63 48 77 1e 80 3d 3b 6e 6b 01 00 75 15 48 c7 c7 93 24 34 82 c6 05 2b 6e 6b 01 01 e8 d1 38 fc ff <0f> 0b 4c 39 a5 28 0a 00 00 79 0e 48 c7 c7 45 d6 32 82 e8 32 5f 01 [ 3.302613] RSP: 0000:ffffffff82603eb8 EFLAGS: 00010082 [ 3.310703] RAX: 0000000000000000 RBX: ffff88813fc2a2e8 RCX: 0000000000000000 [ 3.321660] RDX: 0000000000000026 RSI: ffffffff82c4afa6 RDI: ffffffff82c4b3a6 [ 3.332536] RBP: ffff88813fc29a00 R08: ffffffff82c4af80 R09: 0000000000000026 [ 3.343234] R10: 0000000000000000 R11: ffffffff82603ccf R12: 0000000000000000 [ 3.354133] R13: 0000000000029a00 R14: ffff88813fc29bc0 R15: ffff88813fc29a40 [ 3.365277] FS: 0000000000000000(0000) GS:ffff88813fc00000(0000) knlGS:0000000000000000 [ 3.377714] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 3.386474] CR2: ffff88813ffff000 CR3: 0000000002612000 CR4: 00000000000006b0 [ 3.397423] Call Trace: [ 3.401223] sched_init+0x37e/0x3fe [ 3.406629] start_kernel+0x267/0x50a [ 3.412198] ? x86_family+0x5/0x1d [ 3.417442] secondary_startup_64+0xb6/0xc0 [ 3.423800] random: get_random_bytes called from init_oops_id+0x22/0x31 with crng_init=0 [ 3.436167] ---[ end trace b2352b5ced6eae1c ]--- To reproduce: # build kernel cd linux cp config-5.3.0-rc1-00388-gac1f97be8df987 .config make HOSTCC=gcc-7 CC=gcc-7 ARCH=x86_64 olddefconfig prepare modules_prepare bzImage git clone https://github.com/intel/lkp-tests.git cd lkp-tests bin/lkp qemu -k <bzImage> job-script # job-script is attached in this email Thanks, lkp