FYI, we noticed the following commit (built with gcc-7): commit: 7e47f04b385fd3508c5a49f6c196f0715d20bc41 ("shmem: Convert shmem_add_to_page_cache to XArray") git://git.infradead.org/users/willy/linux-dax.git xarray-2017-12-04 in testcase: boot on test machine: qemu-system-x86_64 -enable-kvm -cpu host -smp 2 -m 4G caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace): +------------------------------------------------+------------+------------+ | | 0f7c4657cf | 7e47f04b38 | +------------------------------------------------+------------+------------+ | boot_successes | 16 | 5 | | boot_failures | 0 | 11 | | BUG:kernel_hang_in_test_stage | 0 | 3 | | RIP:smp_call_function_single | 0 | 8 | | Kernel_panic-not_syncing:softlockup:hung_tasks | 0 | 8 | | INFO:rcu_sched_detected_stalls_on_CPUs/tasks | 0 | 1 | | RIP:get_page_from_freelist | 0 | 1 | | RIP:__zone_watermark_ok | 0 | 1 | | BUG:soft_lockup-CPU##stuck_for#s | 0 | 5 | +------------------------------------------------+------------+------------+ Starting Create list of required st... nodes for the current kernel... Mounting Huge Pages File System... Mounting Debug File System... [ 128.157096] CPU: 1 PID: 113 Comm: (journald) Not tainted 4.15.0-rc2-00055-g7e47f04 #1 [ 128.157096] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 [ 128.157096] task: 00000000a7ddecce task.stack: 000000006e682bf2 [ 128.157096] RIP: 0010:smp_call_function_single+0xcf/0xf0 [ 128.157096] RSP: 0018:ffffc90000947cc0 EFLAGS: 00000202 ORIG_RAX: ffffffffffffff11 [ 128.157096] RAX: 0000000000000000 RBX: ffff88007f5b02a0 RCX: 0000000000000830 [ 128.157096] RDX: 0000000000000003 RSI: 00000000000000fb RDI: 0000000000000830 [ 128.157096] RBP: ffffc90000947cf0 R08: 0000000000000000 R09: 0000000000000003 [ 128.157096] R10: ffffc90000947d18 R11: 0000000000000010 R12: 0000000000000000 [ 128.157096] R13: 0000000000000002 R14: 0000000000000000 R15: ffff88013fd16c78 [ 128.157096] FS: 00007fc17b8b6900(0000) GS:ffff88013fd00000(0000) knlGS:0000000000000000 [ 128.157096] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 128.157096] CR2: 000055b9f613e828 CR3: 000000007f73e002 CR4: 00000000000206e0 [ 128.157096] Call Trace: [ 128.157096] ? x86_configure_nx+0x50/0x50 [ 128.157096] ? x86_configure_nx+0x50/0x50 [ 128.157096] ? on_each_cpu+0x36/0x70 [ 128.157096] on_each_cpu+0x36/0x70 [ 128.157096] flush_tlb_kernel_range+0x38/0x60 [ 128.157096] __purge_vmap_area_lazy+0x4d/0xe0 [ 128.157096] vm_unmap_aliases+0x115/0x150 [ 128.157096] change_page_attr_set_clr+0x28e/0x420 [ 128.157096] ? bpf_convert_filter+0x9d3/0xa00 [ 128.157096] set_memory_ro+0x26/0x30 [ 128.157096] bpf_prog_select_runtime+0x63/0x100 [ 128.157096] bpf_prepare_filter+0x2b5/0x390 [ 128.157096] ? hardlockup_detector_perf_cleanup+0x80/0x80 [ 128.157096] bpf_prog_create_from_user+0x90/0xf0 [ 128.157096] do_seccomp+0x271/0x680 [ 128.157096] entry_SYSCALL_64_fastpath+0x1a/0x7d [ 128.157096] RIP: 0033:0x7fc179e9ad49 [ 128.157096] RSP: 002b:00007fffd192f548 EFLAGS: 00000246 ORIG_RAX: 000000000000013d [ 128.157096] RAX: ffffffffffffffda RBX: 00000000000001f0 RCX: 00007fc179e9ad49 [ 128.157096] RDX: 000055b9f613a400 RSI: 0000000000000000 RDI: 0000000000000001 [ 128.157096] RBP: 00007fc17a153e48 R08: 000055b9f613a400 R09: 000055b9f613a3a0 [ 128.157096] R10: 0000000000000000 R11: 0000000000000246 R12: 00007fc17a153b78 [ 128.157096] R13: 00000000000000f0 R14: 000055b9f613e720 R15: 00007fc17a153b20 [ 128.157096] Code: 57 f0 7e 48 83 c4 28 41 5a 5d 49 8d 62 f8 c3 48 89 d1 48 89 f2 48 8d 75 d0 e8 8e fe ff ff 8b 55 e8 83 e2 01 74 0a f3 90 8b 55 e8 <83> e2 01 75 f6 eb ca 8b 05 44 a5 5f 01 85 c0 75 89 0f ff eb 85 [ 128.157096] Kernel panic - not syncing: softlockup: hung tasks [ 128.157096] CPU: 1 PID: 113 Comm: (journald) Tainted: G L 4.15.0-rc2-00055-g7e47f04 #1 [ 128.157096] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 [ 128.157096] Call Trace: [ 128.157096] <IRQ> [ 128.157096] dump_stack+0x5c/0x7b [ 128.157096] panic+0xd5/0x232 [ 128.157096] watchdog_timer_fn+0x208/0x210 [ 128.157096] ? watchdog+0x30/0x30 [ 128.157096] __hrtimer_run_queues+0xd3/0x230 [ 128.157096] hrtimer_interrupt+0xa6/0x200 [ 128.157096] smp_apic_timer_interrupt+0x56/0x130 [ 128.157096] apic_timer_interrupt+0x96/0xa0 [ 128.157096] </IRQ> [ 128.157096] RIP: 0010:smp_call_function_single+0xcf/0xf0 [ 128.157096] RSP: 0018:ffffc90000947cc0 EFLAGS: 00000202 ORIG_RAX: ffffffffffffff11 [ 128.157096] RAX: 0000000000000000 RBX: ffff88007f5b02a0 RCX: 0000000000000830 [ 128.157096] RDX: 0000000000000003 RSI: 00000000000000fb RDI: 0000000000000830 [ 128.157096] RBP: ffffc90000947cf0 R08: 0000000000000000 R09: 0000000000000003 [ 128.157096] R10: ffffc90000947d18 R11: 0000000000000010 R12: 0000000000000000 [ 128.157096] R13: 0000000000000002 R14: 0000000000000000 R15: ffff88013fd16c78 [ 128.157096] ? x86_configure_nx+0x50/0x50 [ 128.157096] ? x86_configure_nx+0x50/0x50 [ 128.157096] ? on_each_cpu+0x36/0x70 [ 128.157096] on_each_cpu+0x36/0x70 [ 128.157096] flush_tlb_kernel_range+0x38/0x60 [ 128.157096] __purge_vmap_area_lazy+0x4d/0xe0 [ 128.157096] vm_unmap_aliases+0x115/0x150 [ 128.157096] change_page_attr_set_clr+0x28e/0x420 [ 128.157096] ? bpf_convert_filter+0x9d3/0xa00 [ 128.157096] set_memory_ro+0x26/0x30 [ 128.157096] bpf_prog_select_runtime+0x63/0x100 [ 128.157096] bpf_prepare_filter+0x2b5/0x390 [ 128.157096] ? hardlockup_detector_perf_cleanup+0x80/0x80 [ 128.157096] bpf_prog_create_from_user+0x90/0xf0 [ 128.157096] do_seccomp+0x271/0x680 [ 128.157096] entry_SYSCALL_64_fastpath+0x1a/0x7d [ 128.157096] RIP: 0033:0x7fc179e9ad49 [ 128.157096] RSP: 002b:00007fffd192f548 EFLAGS: 00000246 ORIG_RAX: 000000000000013d [ 128.157096] RAX: ffffffffffffffda RBX: 00000000000001f0 RCX: 00007fc179e9ad49 [ 128.157096] RDX: 000055b9f613a400 RSI: 0000000000000000 RDI: 0000000000000001 [ 128.157096] RBP: 00007fc17a153e48 R08: 000055b9f613a400 R09: 000055b9f613a3a0 [ 128.157096] R10: 0000000000000000 R11: 0000000000000246 R12: 00007fc17a153b78 [ 128.157096] R13: 00000000000000f0 R14: 000055b9f613e720 R15: 00007fc17a153b20 [ 128.157096] Shutting down cpus with NMI [ 128.157096] Kernel Offset: disabled To reproduce: 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