FYI, we noticed the following commit (built with gcc-7): commit: 54e140662331938de5434a9a49705b7318c58fbf ("mm: memcg/slab: charge individual slab objects instead of pages") https://github.com/rgushchin/linux.git new_slab.1 in testcase: boot on test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 8G caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace): +----------------------------------------------------+------------+------------+ | | d2c043a61e | 54e1406623 | +----------------------------------------------------+------------+------------+ | boot_successes | 4 | 0 | | boot_failures | 4 | 6 | | BUG:kernel_NULL_pointer_dereference,address | 2 | | | Oops:#[##] | 2 | 6 | | RIP:_raw_spin_trylock | 2 | | | Kernel_panic-not_syncing:Fatal_exception | 2 | 6 | | INFO:rcu_sched_self-detected_stall_on_CPU | 2 | | | RIP:queued_spin_lock_slowpath | 2 | | | BUG:kernel_hang_in_boot-around-mounting-root_stage | 2 | | | BUG:unable_to_handle_page_fault_for_address | 0 | 6 | | RIP:atomic_try_cmpxchg | 0 | 6 | +----------------------------------------------------+------------+------------+ If you fix the issue, kindly add following tag Reported-by: kernel test robot <rong.a.chen(a)intel.com&gt; [ 11.768604] BUG: unable to handle page fault for address: ffffffff81bf8872 [ 11.770373] #PF: supervisor write access in kernel mode [ 11.771860] #PF: error_code(0x0003) - permissions violation [ 11.773320] PGD 260d067 P4D 260d067 PUD 260e063 PMD 1a001e1 [ 11.774790] Oops: 0003 [#1] SMP PTI [ 11.775941] CPU: 1 PID: 1 Comm: systemd Not tainted 5.3.0-rc7-mm1-00289-g54e1406623319 #1 [ 11.778343] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 [ 11.780903] RIP: 0010:atomic_try_cmpxchg+0x4/0x12 [ 11.782299] Code: 40 10 00 00 00 00 58 5b 5d 41 5c 41 5d c3 31 c0 48 81 ff b0 b8 bf 81 72 0c 31 c0 48 81 ff c9 bc bf 81 0f 92 c0 c3 8b 0e 89 c8 <f0> 0f b1 17 89 c1 0f 94 c0 74 02 89 0e c3 53 ba 01 00 00 00 48 89 [ 11.786832] RSP: 0018:ffffc90000013c30 EFLAGS: 00010246 [ 11.788226] RAX: 0000000000000000 RBX: ffffffff81bf8872 RCX: 0000000000000000 [ 11.789886] RDX: 0000000000000001 RSI: ffffc90000013c3c RDI: ffffffff81bf8872 [ 11.791634] RBP: ffffffff81bf8872 R08: 0000000000000000 R09: ffffc90000013e50 [ 11.793409] R10: ffffc90000013e48 R11: 0000000000000000 R12: ffffc90000013e50 [ 11.795229] R13: ffff88822a6e8020 R14: 0000000000004041 R15: 0000000000001800 [ 11.797025] FS: 00007f3ed3233940(0000) GS:ffff88823fd00000(0000) knlGS:0000000000000000 [ 11.799557] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 11.801194] CR2: ffffffff81bf8872 CR3: 00000001cc538000 CR4: 00000000000406e0 [ 11.803087] Call Trace: [ 11.804184] do_raw_spin_lock+0x2f/0x5a [ 11.805422] ? _cond_resched+0x25/0x29 [ 11.806671] fast_dput+0x31/0x82 [ 11.807815] ? _cond_resched+0x25/0x29 [ 11.809048] dput+0x3c/0x14d [ 11.810132] path_put+0x12/0x1b [ 11.811301] terminate_walk+0x48/0x68 [ 11.812508] path_lookupat+0x18d/0x1b3 [ 11.813793] ? slab_free_freelist_hook+0x19/0x68 [ 11.815336] filename_lookup+0x8c/0xfc [ 11.816590] ? ___might_sleep+0x3a/0x126 [ 11.817845] ? _cond_resched+0x25/0x29 [ 11.819166] ? getname_flags+0x29/0x156 [ 11.820397] ? kmem_cache_alloc+0x103/0x19f [ 11.821685] ? vfs_statx+0x70/0xcc [ 11.822887] vfs_statx+0x70/0xcc [ 11.824039] __do_sys_newfstatat+0x31/0x63 [ 11.825365] ? tracer_hardirqs_off+0x1b/0xfb [ 11.826702] ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe [ 11.828260] ? trace_hardirqs_off_caller+0x41/0x43 [ 11.829581] ? tracer_hardirqs_on+0x1b/0xf6 [ 11.831051] do_syscall_64+0x57/0x65 [ 11.832258] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 11.833641] RIP: 0033:0x7f3ed1a4da4a [ 11.834913] Code: 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 83 ff 01 89 f0 48 89 d6 77 1e 48 63 f8 4d 63 d0 48 89 ca b8 06 01 00 00 0f 05 <48> 3d 00 f0 ff ff 77 1a f3 c3 0f 1f 40 00 48 8b 05 11 74 2d 00 64 [ 11.839609] RSP: 002b:00007ffe9e12be48 EFLAGS: 00000246 ORIG_RAX: 0000000000000106 [ 11.842054] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f3ed1a4da4a [ 11.843880] RDX: 00007ffe9e12c030 RSI: 00005594416198a5 RDI: 0000000000000003 [ 11.845643] RBP: 0000559441c57011 R08: 0000000000001000 R09: 0000000000080000 [ 11.847503] R10: 0000000000001000 R11: 0000000000000246 R12: 0000000000000001 [ 11.849290] R13: 0000000000000400 R14: 00007ffe9e12be58 R15: 00007f3ed3233740 [ 11.851198] Modules linked in: [ 11.852325] CR2: ffffffff81bf8872 [ 11.853441] ---[ end trace 4813af85c191fcb5 ]--- To reproduce: # build kernel cd linux cp config-5.3.0-rc7-mm1-00289-g54e1406623319 .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, Rong Chen