FYI, we noticed the following commit: commit: 6b25539325e4025b660ac5f050e2829f2c718b79 ("mm: Copy accessing sub-page last when copy huge page") git://bee.sh.intel.com/git/yhuang/linux.git clear_huge_page_hint 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): +------------------------------------------+------------+------------+ | | eebfc5a319 | 6b25539325 | +------------------------------------------+------------+------------+ | boot_successes | 4 | 0 | | boot_failures | 0 | 3 | | kernel_BUG_at_mm/memory.c | 0 | 3 | | invalid_opcode:#[##] | 0 | 3 | | Kernel_panic-not_syncing:Fatal_exception | 0 | 3 | +------------------------------------------+------------+------------+ [ 86.117783] kernel BUG at mm/memory.c:4382! [ 86.138984] invalid opcode: 0000 [#1] SMP [ 86.155052] Modules linked in: sr_mod cdrom sg ata_generic [ 86.174854] CPU: 1 PID: 3238 Comm: dpkg Not tainted 4.12.0-rc7-mm1-00387-g6b255393 #1 [ 86.204315] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.3-20161025_171302-gandalf 04/01/2014 [ 86.235707] task: ffff880102a2be80 task.stack: ffffc90000994000 [ 86.253471] RIP: 0010:copy_user_huge_page+0x1e6/0x4e7 [ 86.269611] RSP: 0000:ffffc90000997ce8 EFLAGS: 00010206 [ 86.286206] RAX: 0000004d28800200 RBX: ffffea0004ed8000 RCX: ffff88012e5e1180 [ 86.306363] RDX: 0000004d28800200 RSI: 000000000000111c RDI: ffffffff81e5f6e0 [ 86.326452] RBP: ffffc90000997d28 R08: 0000000000000200 R09: 0000004d2893f000 [ 86.346182] R10: 0000000000140000 R11: 0000000000000000 R12: ffffea0004f18000 [ 86.365273] R13: 0000000000000200 R14: 0000004d28800000 R15: 00000000000342ca [ 86.384460] FS: 00007f21140db800(0000) GS:ffff88013fd00000(0000) knlGS:0000000000000000 [ 86.411161] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 86.427851] CR2: 0000004d2893ffd8 CR3: 0000000107795000 CR4: 00000000000006e0 [ 86.447059] Call Trace: [ 86.458305] ? mem_cgroup_try_charge+0x10c/0x1d9 [ 86.473215] do_huge_pmd_wp_page+0x431/0xdaa [ 86.487312] ? filemap_map_pages+0x1ff/0x33d [ 86.501317] __handle_mm_fault+0x38f/0xecf [ 86.515023] ? __do_page_fault+0x33e/0x3e5 [ 86.528861] handle_mm_fault+0x108/0x192 [ 86.542374] __do_page_fault+0x20e/0x3e5 [ 86.556106] trace_do_page_fault+0x51/0xde [ 86.569910] do_async_page_fault+0x31/0x5d [ 86.584011] async_page_fault+0x28/0x30 [ 86.597812] RIP: 0033:0x7f211396f290 [ 86.610808] RSP: 002b:00007ffd01259540 EFLAGS: 00010246 [ 86.626922] RAX: 00007f2113c94ba8 RBX: 00007f2113c94b20 RCX: 00007f2113c94bb8 [ 86.645262] RDX: 00007f2113c94ba8 RSI: 0000000000000002 RDI: 00007f2113c94b30 [ 86.664180] RBP: 0000000000000038 R08: 00007f21140db800 R09: 0000000000000040 [ 86.682790] R10: 00007f211347d270 R11: 0000000000000202 R12: 0000004d28467900 [ 86.701554] R13: 0000000000000040 R14: 0000004d2893ff90 R15: 00007f2113c94b20 [ 86.720371] Code: d0 e8 1e 63 f1 ff e8 30 e0 8a 00 4c 8b 4d d0 44 89 ea 4d 39 ce 4c 89 c8 49 0f 43 c6 4c 01 f2 48 39 d0 48 0f 47 c2 49 39 c1 74 02 <0f> 0b 4d 29 f1 49 c1 e9 0c 47 8d 3c 09 44 89 4d d0 45 39 fd 0f [ 86.771549] RIP: copy_user_huge_page+0x1e6/0x4e7 RSP: ffffc90000997ce8 [ 86.789793] ---[ end trace 5cf0b93c7ab51648 ]--- To reproduce: git clone https://github.com/01org/lkp-tests.git cd lkp-tests bin/lkp qemu -k <bzImage> job-script # job-script is attached in this email Thanks, Kernel Test Robot