FYI, we noticed the following commit: https://github.com/0day-ci/linux Michal-Hocko/tree-wide-get-rid-of-__GFP_REPEAT-for-order-0-allocations-part-I/20160428-212857 commit 8caa6068fa57b7187daedbfa9507d5ba4f962a41 ("md: simplify free_params for kmalloc vs vmalloc fallback") on test machine: vm-lkp-wsx03-1G: 1 threads qemu-system-x86_64 -enable-kvm -cpu host with 1G memory caused below changes: +------------------------------------------+------------+------------+ | | 0b9466ab4a | 8caa6068fa | +------------------------------------------+------------+------------+ | boot_successes | 10 | 2 | | boot_failures | 0 | 6 | | kernel_BUG_at_mm/slub.c | 0 | 6 | | invalid_opcode:#[##]SMP | 0 | 6 | | RIP:kfree | 0 | 6 | | Kernel_panic-not_syncing:Fatal_exception | 0 | 6 | | backtrace:do_vfs_ioctl | 0 | 6 | | backtrace:SyS_ioctl | 0 | 6 | +------------------------------------------+------------+------------+ [ 15.781036] device-mapper: uevent: version 1.0.3 [ 15.782750] device-mapper: ioctl: 4.34.0-ioctl (2015-10-28) initialised: dm-devel@redhat.com [ 15.785199] ------------[ cut here ]------------ [ 15.786335] kernel BUG at mm/slub.c:3656! [ 15.787557] invalid opcode: 0000 [#1] SMP [ 15.788798] Modules linked in: dm_mod rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver sg sr_mod cdrom ata_generic pata_acpi ppdev crc32c_intel snd_pcm snd_timer snd soundcore pcspkr serio_raw ata_piix i2c_piix4 libata parport_pc floppy parport acpi_cpufreq [ 15.795806] CPU: 0 PID: 415 Comm: dmsetup Not tainted 4.6.0-rc3-00055-g8caa606 #1 [ 15.797800] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Debian-1.8.2-1 04/01/2014 [ 15.800016] task: ffff88003e87a440 ti: ffff88003f5d8000 task.ti: ffff88003f5d8000 [ 15.802071] RIP: 0010:[] [] kfree+0x131/0x170 [ 15.804179] RSP: 0018:ffff88003f5dbcd0 EFLAGS: 00010246 [ 15.805395] RAX: dead000000000100 RBX: ffff88003f5dbd28 RCX: 0000000000000000 [ 15.806812] RDX: 0000000000000000 RSI: ffff88003f5dbd28 RDI: ffff88003f5dbd28 [ 15.808348] RBP: ffff88003f5dbce8 R08: 0000000000000131 R09: 0000000000000000 [ 15.809769] R10: ffffea0000fd76c0 R11: 0000000000000000 R12: 0000000000000000 [ 15.811216] R13: ffffffff811944ca R14: ffff88003f5dbd28 R15: 0000000000000000 [ 15.812635] FS: 00007fda6089c800(0000) GS:ffff880037000000(0000) knlGS:0000000000000000 [ 15.814653] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 15.815906] CR2: 000055ad4817a000 CR3: 000000003ee67000 CR4: 00000000000006f0 [ 15.817353] Stack: [ 15.818142] 000055ad48177120 0000000000000000 0000000000000000 ffff88003f5dbcf8 [ 15.820375] ffffffff811944ca ffff88003f5dbe88 ffffffffa01d6552 ffff88003f5dbd80 [ 15.822589] ffffffff811ce6a3 0000000100000001 0000000000000131 0000002200000004 [ 15.824802] Call Trace: [ 15.825674] [] kvfree+0x2a/0x40 [ 15.826803] [] ctl_ioctl+0x262/0x520 [dm_mod] [ 15.828097] [] ? alloc_pages_vma+0xb3/0x230 [ 15.829374] [] dm_ctl_ioctl+0x13/0x20 [dm_mod] [ 15.830670] [] do_vfs_ioctl+0x8f/0x670 [ 15.831903] [] ? security_file_ioctl+0x43/0x60 [ 15.833219] [] SyS_ioctl+0x79/0x90 [ 15.834403] [] entry_SYSCALL_64_fastpath+0x1a/0xa4 [ 15.835747] Code: da 4c 89 ee ff d0 49 8b 04 24 48 85 c0 75 e6 65 ff 0d 7c 39 e3 7e e9 f9 fe ff ff 49 8b 02 f6 c4 40 75 0a 49 8b 42 20 a8 01 75 02 <0f> 0b 49 8b 02 31 f6 f6 c4 40 74 04 41 8b 72 6c 4c 89 d7 e8 07 [ 15.844575] RIP [] kfree+0x131/0x170 [ 15.845849] RSP [ 15.846853] ---[ end trace 3d847d94459925d4 ]--- [ 15.848721] Kernel panic - not syncing: Fatal exception FYI, raw QEMU command line is: qemu-system-x86_64 -enable-kvm -cpu host -kernel /pkg/linux/x86_64-rhel/gcc-4.9/8caa6068fa57b7187daedbfa9507d5ba4f962a41/vmlinuz-4.6.0-rc3-00055-g8caa606 -append 'root=/dev/ram0 user=lkp job=/lkp/scheduled/vm-lkp-wsx03-1G-5/bisect_fsmark-1x-32t-1HDD-btrfs-9B-400M-fsyncBeforeClose-16d-256fpd-debian-x86_64-2015-02-07.cgz-x86_64-rhel-8caa6068fa57b7187daedbfa9507d5ba4f962a41-20160429-80077-zxsib7-0.yaml ARCH=x86_64 kconfig=x86_64-rhel branch=linux-devel/devel-hourly-2016042901 commit=8caa6068fa57b7187daedbfa9507d5ba4f962a41 BOOT_IMAGE=/pkg/linux/x86_64-rhel/gcc-4.9/8caa6068fa57b7187daedbfa9507d5ba4f962a41/vmlinuz-4.6.0-rc3-00055-g8caa606 max_uptime=2016 RESULT_ROOT=/result/fsmark/1x-32t-1HDD-btrfs-9B-400M-fsyncBeforeClose-16d-256fpd/vm-lkp-wsx03-1G/debian-x86_64-2015-02-07.cgz/x86_64-rhel/gcc-4.9/8caa6068fa57b7187daedbfa9507d5ba4f962a41/0 LKP_SERVER=inn earlyprintk=ttyS0,115200 systemd.log_level=err debug apic=debug sysrq_always_enabled rcupdate.rcu_cpu_stall_timeout=100 panic=-1 softlockup_panic=1 nmi_watchdog=panic oops=panic load_ramdisk=2 prompt_ramdisk=0 console=ttyS0,115200 console=tty0 vga=normal rw ip=::::vm-lkp-wsx03-1G-5::dhcp' -initrd /fs/sdc1/initrd-vm-lkp-wsx03-1G-5 -m 1024 -smp 1 -device e1000,netdev=net0 -netdev user,id=net0,hostfwd=tcp::23604-:22 -boot order=nc -no-reboot -watchdog i6300esb -rtc base=localtime -drive file=/fs/sdc1/disk0-vm-lkp-wsx03-1G-5,media=disk,if=virtio -drive file=/fs/sdc1/disk1-vm-lkp-wsx03-1G-5,media=disk,if=virtio -pidfile /dev/shm/kboot/pid-vm-lkp-wsx03-1G-5 -serial file:/dev/shm/kboot/serial-vm-lkp-wsx03-1G-5 -daemonize -display none -monitor null To reproduce: git clone git://git.kernel.org/pub/scm/linux/kernel/git/wfg/lkp-tests.git cd lkp-tests bin/lkp install job.yaml # job file is attached in this email bin/lkp run job.yaml Thanks, Kernel Test Robot