FYI, we noticed the below changes on

https://github.com/0day-ci/linux Laura-Abbott/mm-slub-Skip-CPU-slab-activation-when-debugging/20160329-065544
commit 923e73a1d7ab188f43f117b4c4eaf5e0ae345c37 ("mm/slub: Skip CPU slab activation when debugging")


[    5.788861] Key type id_legacy registered
[    5.790735] Installing knfsd (copyright (C) 1996 okir@monad.swb.de).
[    5.817687] ------------[ cut here ]------------
[    5.819447] kernel BUG at mm/slub.c:1682!
[    5.822976] invalid opcode: 0000 [#1] SMP 
[    5.824868] Modules linked in:
[    5.826442] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.6.0-rc1-00001-g923e73a #122
[    5.829454] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Debian-1.8.2-1 04/01/2014
[    5.832675] task: ffff880012028040 ti: ffff880012024000 task.ti: ffff880012024000
[    5.838380] RIP: 0010:[<ffffffff811ddf82>]  [<ffffffff811ddf82>] get_partial_node+0x138/0x693
[    5.842725] RSP: 0018:ffff880012027b80  EFLAGS: 00010046
[    5.845375] RAX: 0000000100010001 RBX: ffffe8ffffc01ba0 RCX: ef7bdef7bdef7bdf
[    5.848070] RDX: 0000000000000001 RSI: ffff88000d61d258 RDI: 0000000000000046
[    5.850232] RBP: ffff880012027c70 R08: 00000000be162c32 R09: 0000000000000004
[    5.853172] R10: ffff880012027ae8 R11: 0000000000000000 R12: ffff88000d61d240
[    5.855856] R13: ffff88000d634f40 R14: ffffea0000359c00 R15: 0000000000000000
[    5.858537] FS:  0000000000000000(0000) GS:ffff880013400000(0000) knlGS:0000000000000000
[    5.861994] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    5.864060] CR2: 0000000000000000 CR3: 0000000002418000 CR4: 00000000000006f0
[    5.865925] Stack:
[    5.866980]  024000c012028870 ffffe8ffffc01ba0 ffff88000d61d290 000000008108acb6
[    5.869421]  ffffea0000359c20 0000000100010001 ffff88000d61d270 0000000000000000
[    5.871509]  ffff8800135d63d8 ffff880012028040 ffff880012027ca0 ffffffff810e99f0
[    5.874286] Call Trace:
[    5.875581]  [<ffffffff810e99f0>] ? __lock_acquire+0x6df/0x192a
[    5.877557]  [<ffffffff810c5116>] ? finish_task_switch+0x12f/0x1f4
[    5.879538]  [<ffffffff810e6084>] ? __lock_is_held+0x3c/0x57
[    5.881471]  [<ffffffff811de84b>] ___slab_alloc+0x36e/0x70f
[    5.883313]  [<ffffffff810cfa81>] ? local_clock+0x20/0x22
[    5.885196]  [<ffffffff811de84b>] ? ___slab_alloc+0x36e/0x70f
[    5.887112]  [<ffffffff81191334>] ? mempool_alloc_slab+0x1f/0x21
[    5.889130]  [<ffffffff810e9048>] ? trace_hardirqs_on+0xd/0xf
[    5.891027]  [<ffffffff81cb1bf6>] ? _raw_spin_unlock_irq+0x2c/0x3d
[    5.893210]  [<ffffffff810c5151>] ? finish_task_switch+0x16a/0x1f4
[    5.895180]  [<ffffffff810c5116>] ? finish_task_switch+0x12f/0x1f4
[    5.897376]  [<ffffffff81191334>] ? mempool_alloc_slab+0x1f/0x21
[    5.899322]  [<ffffffff811dec3b>] __slab_alloc+0x4f/0x83
[    5.901221]  [<ffffffff811dec3b>] ? __slab_alloc+0x4f/0x83
[    5.903075]  [<ffffffff81191334>] ? mempool_alloc_slab+0x1f/0x21
[    5.905582]  [<ffffffff811decf5>] kmem_cache_alloc+0x86/0x297
[    5.907497]  [<ffffffff81190ff6>] ? __check_element+0x106/0x106
[    5.909727]  [<ffffffff81191334>] mempool_alloc_slab+0x1f/0x21
[    5.911647]  [<ffffffff8119151d>] mempool_create_node+0xf6/0x117
[    5.913678]  [<ffffffff81191315>] ? mempool_destroy+0x41/0x41
[    5.915582]  [<ffffffff827e91ab>] ? init_nls_utf8+0x27/0x27
[    5.918122]  [<ffffffff81191556>] mempool_create+0x18/0x1a
[    5.920077]  [<ffffffff827e9488>] init_cifs+0x2dd/0x3b7
[    5.921872]  [<ffffffff81000402>] do_one_initcall+0xe7/0x177
[    5.923813]  [<ffffffff827af0b2>] kernel_init_freeable+0x1ca/0x252
[    5.925776]  [<ffffffff81ca4072>] kernel_init+0xe/0xf5
[    5.927536]  [<ffffffff81cb25f2>] ret_from_fork+0x22/0x50
[    5.929779]  [<ffffffff81ca4064>] ? rest_init+0x13b/0x13b
[    5.931604] Code: 32 01 00 74 12 49 8d 7c 24 18 e8 39 81 f0 ff 85 c0 0f 84 c0 04 00 00 4d 8b 7e 10 49 8b 46 18 4d 85 ff 48 89 85 38 ff ff ff 75 02 <0f> 0b 49 63 45 20 49 8b 1c 07 48 8b 85 38 ff ff ff 48 89 85 68 
[    5.945658] RIP  [<ffffffff811ddf82>] get_partial_node+0x138/0x693
[    5.947969]  RSP <ffff880012027b80>
[    5.949471] ---[ end trace 4e87f58f9fe358d9 ]---
[    5.951169] Kernel panic - not syncing: Fatal exception


FYI, raw QEMU command line is:

	qemu-system-x86_64 -enable-kvm -cpu Westmere -kernel /pkg/linux/x86_64-nfsroot/gcc-5/923e73a1d7ab188f43f117b4c4eaf5e0ae345c37/vmlinuz-4.6.0-rc1-00001-g923e73a -append 'root=/dev/ram0 user=lkp job=/lkp/scheduled/vm-kbuild-yocto-ia32-1/bisect_boot-1-yocto-minimal-i386.cgz-x86_64-nfsroot-923e73a1d7ab188f43f117b4c4eaf5e0ae345c37-20160329-24125-irq8fy-1.yaml ARCH=x86_64 kconfig=x86_64-nfsroot branch=linux-devel/devel-spot-201603290654 commit=923e73a1d7ab188f43f117b4c4eaf5e0ae345c37 BOOT_IMAGE=/pkg/linux/x86_64-nfsroot/gcc-5/923e73a1d7ab188f43f117b4c4eaf5e0ae345c37/vmlinuz-4.6.0-rc1-00001-g923e73a max_uptime=600 RESULT_ROOT=/result/boot/1/vm-kbuild-yocto-ia32/yocto-minimal-i386.cgz/x86_64-nfsroot/gcc-5/923e73a1d7ab188f43f117b4c4eaf5e0ae345c37/0 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-kbuild-yocto-ia32-1::dhcp drbd.minor_count=8'  -initrd /fs/sdg1/initrd-vm-kbuild-yocto-ia32-1 -m 320 -smp 1 -device e1000,netdev=net0 -netdev user,id=net0 -boot order=nc -no-reboot -watchdog i6300esb -rtc base=localtime -drive file=/fs/sdg1/disk0-vm-kbuild-yocto-ia32-1,media=disk,if=virtio -pidfile /dev/shm/kboot/pid-vm-kbuild-yocto-ia32-1 -serial file:/dev/shm/kboot/serial-vm-kbuild-yocto-ia32-1 -daemonize -display none -monitor null 




Thanks,
Kernel Test Robot