FYI, we noticed the following commit: commit: ef2271279c8ddc7a1ae688168b120a2b0bf3b463 ("ksm: introduce ksm_max_page_sharing per page deduplication limit") https://git.kernel.org/cgit/linux/kernel/git/andrea/aa.git master in testcase: trinity with following parameters: runtime: 300s test-description: Trinity is a linux system call fuzz tester. test-url: http://codemonkey.org.uk/projects/trinity/ on test machine: qemu-system-i386 -enable-kvm -smp 2 -m 320M caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace): +------------------------------------------+------------+------------+ | | 16bcd858c4 | ef2271279c | +------------------------------------------+------------+------------+ | boot_successes | 46 | 21 | | boot_failures | 0 | 23 | | kernel_BUG_at_mm/mmap.c | 0 | 23 | | invalid_opcode:#[##] | 0 | 23 | | EIP:unmapped_area_topdown | 0 | 23 | | Kernel_panic-not_syncing:Fatal_exception | 0 | 23 | +------------------------------------------+------------+------------+ [ 36.299632] kernel BUG at mm/mmap.c:1968! [ 36.299632] kernel BUG at mm/mmap.c:1968! [ 36.303491] invalid opcode: 0000 [#1] [ 36.303491] invalid opcode: 0000 [#1] [ 36.304959] Modules linked in: [ 36.304959] Modules linked in: [ 36.308105] CPU: 0 PID: 2440 Comm: trinity-c2 Not tainted 4.12.0-rc6-00024-gef22712 #1 [ 36.308105] CPU: 0 PID: 2440 Comm: trinity-c2 Not tainted 4.12.0-rc6-00024-gef22712 #1 [ 36.311887] task: 8a32b300 task.stack: 897d2000 [ 36.311887] task: 8a32b300 task.stack: 897d2000 [ 36.313752] EIP: unmapped_area_topdown+0x131/0x140 [ 36.313752] EIP: unmapped_area_topdown+0x131/0x140 [ 36.315995] EFLAGS: 00010206 CPU: 0 [ 36.315995] EFLAGS: 00010206 CPU: 0 [ 36.317318] EAX: 6c2ef000 EBX: 6c3f0000 ECX: 6c400000 EDX: 6c2ef000 [ 36.317318] EAX: 6c2ef000 EBX: 6c3f0000 ECX: 6c400000 EDX: 6c2ef000 [ 36.320170] ESI: 00101000 EDI: 897d3eac EBP: 897d3e98 ESP: 897d3e6c [ 36.320170] ESI: 00101000 EDI: 897d3eac EBP: 897d3e98 ESP: 897d3e6c [ 36.323477] DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 0068 [ 36.323477] DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 0068 [ 36.328281] CR0: 80050033 CR2: 08a14fc0 CR3: 111db000 CR4: 00000690 [ 36.328281] CR0: 80050033 CR2: 08a14fc0 CR3: 111db000 CR4: 00000690 [ 36.331708] Call Trace: [ 36.331708] Call Trace: [ 36.332981] arch_get_unmapped_area_topdown+0x81/0x121 [ 36.332981] arch_get_unmapped_area_topdown+0x81/0x121 [ 36.335498] ? arch_get_unmapped_area+0xd9/0xd9 [ 36.335498] ? arch_get_unmapped_area+0xd9/0xd9 [ 36.337251] get_unmapped_area+0x4d/0x89 [ 36.337251] get_unmapped_area+0x4d/0x89 [ 36.340782] do_mmap+0xd2/0x2ee [ 36.340782] do_mmap+0xd2/0x2ee [ 36.342221] vm_mmap_pgoff+0x50/0x80 [ 36.342221] vm_mmap_pgoff+0x50/0x80 [ 36.343760] SyS_mmap_pgoff+0xec/0x132 [ 36.343760] SyS_mmap_pgoff+0xec/0x132 [ 36.345436] do_fast_syscall_32+0xca/0x184 [ 36.345436] do_fast_syscall_32+0xca/0x184 [ 36.347739] entry_SYSENTER_32+0x4c/0x7b [ 36.347739] entry_SYSENTER_32+0x4c/0x7b [ 36.350067] EIP: 0x6f7f3bd5 [ 36.350067] EIP: 0x6f7f3bd5 [ 36.353342] EFLAGS: 00000246 CPU: 0 [ 36.353342] EFLAGS: 00000246 CPU: 0 [ 36.354982] EAX: ffffffda EBX: 00000000 ECX: 00101000 EDX: 00000003 [ 36.354982] EAX: ffffffda EBX: 00000000 ECX: 00101000 EDX: 00000003 [ 36.359594] ESI: 00000022 EDI: ffffffff EBP: 00000000 ESP: 77b3210c [ 36.359594] ESI: 00000022 EDI: ffffffff EBP: 00000000 ESP: 77b3210c [ 36.363729] DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 007b [ 36.363729] DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 007b [ 36.366290] Code: 74 a9 8b 4b 04 eb a4 39 df 0f 47 fb 2b 7d e4 89 fa 89 f8 8b 7d f0 2b 47 14 23 45 e0 29 c2 39 55 e8 89 d0 76 02 0f 0b 39 d1 76 07 <0f> 0b b8 f4 ff ff ff 83 c4 20 5b 5e 5f 5d c3 55 89 e5 56 53 89 [ 36.366290] Code: 74 a9 8b 4b 04 eb a4 39 df 0f 47 fb 2b 7d e4 89 fa 89 f8 8b 7d f0 2b 47 14 23 45 e0 29 c2 39 55 e8 89 d0 76 02 0f 0b 39 d1 76 07 <0f> 0b b8 f4 ff ff ff 83 c4 20 5b 5e 5f 5d c3 55 89 e5 56 53 89 [ 36.375107] EIP: unmapped_area_topdown+0x131/0x140 SS:ESP: 0068:897d3e6c [ 36.375107] EIP: unmapped_area_topdown+0x131/0x140 SS:ESP: 0068:897d3e6c [ 36.378202] ---[ end trace ce5cd97e71feb177 ]--- 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, Xiaolong