FYI, we noticed the following commit (built with gcc-7): commit: 6209f6fc62835d84c2a92d237588a114e39436ce ("mm, oom: rework mmap_exit vs. oom_reaper synchronization") https://github.com/0day-ci/linux UPDATE-20180911-024633/Tetsuo-Handa/mm-oom-Fix-unnecessary-killing-of-additional-processes/20180910-163452 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-x86_64 -enable-kvm -cpu Haswell,+smep,+smap -smp 2 -m 512M caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace): +------------------------------------------+------------+------------+ | | a49a9dcce8 | 6209f6fc62 | +------------------------------------------+------------+------------+ | boot_successes | 4 | 0 | | boot_failures | 11 | 9 | | invoked_oom-killer:gfp_mask=0x | 10 | 9 | | Mem-Info | 11 | 9 | | Out_of_memory:Kill_process | 11 | 9 | | general_protection_fault:#[##] | 0 | 7 | | RIP:__oom_reap_task_mm | 0 | 8 | | Kernel_panic-not_syncing:Fatal_exception | 0 | 8 | +------------------------------------------+------------+------------+ [ 75.095365] [ 431] 0 431 4460 1839 69632 0 -1000 sed [ 75.116040] [ 439] 0 439 4469 729 73728 0 -1000 rc.local [ 75.137487] [ 440] 0 440 1078 313 53248 0 0 sleep [ 75.158428] [ 441] 0 441 4990 178 61440 0 -1000 lkp-setup-rootf [ 75.181175] [ 442] 0 442 85 49 40960 0 -1000 run-parts [ 75.202754] Out of memory: Kill process 397 (rc) score 7 or sacrifice child [ 75.219642] Killed process 427 (S99rc.local) total-vm:18036kB, anon-rss:420kB, file-rss:2704kB, shmem-rss:0kB /etc/init.d/rc: line 149: 427 Killed $debug "$script" $action [ 75.270407] general protection fault: 0000 [#1] DEBUG_PAGEALLOC PTI [ 75.289553] CPU: 0 PID: 11 Comm: oom_reaper Not tainted 4.19.0-rc2-00206-g6209f6f #1 [ 75.309358] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 [ 75.330813] RIP: 0010:__oom_reap_task_mm+0x40/0x180 [ 75.343290] Code: 8b 04 25 28 00 00 00 48 89 45 d0 31 c0 80 8f b2 04 00 00 40 48 8b 1f 48 85 db 0f 84 0b 01 00 00 49 89 fc c6 85 47 ff ff ff 01 <48> 8b 43 50 a9 00 24 40 00 0f 85 e3 00 00 00 48 83 bb 90 00 00 00 [ 75.386036] RSP: 0018:ffff88001d087db8 EFLAGS: 00010202 [ 75.399221] RAX: 6b6b6b6b6b6b6b6b RBX: 6b6b6b6b6b05036b RCX: 00000000000001ab [ 75.416364] RDX: ffff88001d0828e0 RSI: 00000000a0ac31fe RDI: ffff88000d103a80 [ 75.433182] RBP: ffff88001d087e78 R08: 000000004ab0396a R09: 00000000a0ac31fe [ 75.449774] R10: ffff88000d103b78 R11: ffff88001d0822c0 R12: ffff88000d103a80 [ 75.466591] R13: ffff88000d103a80 R14: ffff88000d103b28 R15: ffffffff840b6574 [ 75.483286] FS: 0000000000000000(0000) GS:ffffffff8308c000(0000) knlGS:0000000000000000 [ 75.503824] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 75.518117] CR2: 00007f7171c3b1f4 CR3: 0000000003062003 CR4: 00000000000206b0 [ 75.533929] Call Trace: [ 75.541424] ? oom_reaper+0x1aa/0x4c0 [ 75.550332] oom_reaper+0x36b/0x4c0 [ 75.559503] ? __wake_up_common_lock+0xc0/0xc0 [ 75.569710] kthread+0x151/0x160 [ 75.578584] ? __oom_reap_task_mm+0x180/0x180 [ 75.589480] ? __kthread_create_on_node+0x1e0/0x1e0 [ 75.601818] ret_from_fork+0x24/0x30 [ 75.637304] ---[ end trace 084a6c5aff200732 ]--- [ 75.661129] RIP: 0010:__oom_reap_task_mm+0x40/0x180 [ 75.672375] Code: 8b 04 25 28 00 00 00 48 89 45 d0 31 c0 80 8f b2 04 00 00 40 48 8b 1f 48 85 db 0f 84 0b 01 00 00 49 89 fc c6 85 47 ff ff ff 01 <48> 8b 43 50 a9 00 24 40 00 0f 85 e3 00 00 00 48 83 bb 90 00 00 00 [ 75.717670] RSP: 0018:ffff88001d087db8 EFLAGS: 00010202 [ 75.733410] RAX: 6b6b6b6b6b6b6b6b RBX: 6b6b6b6b6b05036b RCX: 00000000000001ab [ 75.751142] RDX: ffff88001d0828e0 RSI: 00000000a0ac31fe RDI: ffff88000d103a80 [ 75.769090] RBP: ffff88001d087e78 R08: 000000004ab0396a R09: 00000000a0ac31fe [ 75.786955] R10: ffff88000d103b78 R11: ffff88001d0822c0 R12: ffff88000d103a80 [ 75.805100] R13: ffff88000d103a80 R14: ffff88000d103b28 R15: ffffffff840b6574 [ 75.823112] FS: 0000000000000000(0000) GS:ffffffff8308c000(0000) knlGS:0000000000000000 [ 75.845084] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 75.860290] CR2: 00007f7171c3b1f4 CR3: 0000000003062003 CR4: 00000000000206b0 [ 75.878136] Kernel panic - not syncing: Fatal exception [ 75.891719] Kernel Offset: disabled Elapsed time: 80 #!/bin/bash To reproduce: git clone https://github.com/intel/lkp-tests.git cd lkp-tests bin/lkp qemu -k job-script # job-script is attached in this email Thanks, Rong Chen