Hi, Xiaolong, thanks for reporting this. I'll make needed changes in v2. Kirill On 02.04.2018 06:17, kernel test robot wrote: > > FYI, we noticed the following commit (built with gcc-7): > > commit: 42658d54ce4d9c25c8a286651c60cbc869f2f91e ("list_lru: Add memcg argument to list_lru_from_kmem()") > url: https://github.com/0day-ci/linux/commits/Kirill-Tkhai/Improve-shrink_slab-scalability-old-complexity-was-O-n-2-new-is-O-n/20180323-052754 > base: git://git.cmpxchg.org/linux-mmotm.git master > > in testcase: boot > > 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): > > > +------------------------------------------+------------+------------+ > | | 7f23acedf7 | 42658d54ce | > +------------------------------------------+------------+------------+ > | boot_successes | 10 | 0 | > | boot_failures | 0 | 19 | > | BUG:unable_to_handle_kernel | 0 | 19 | > | Oops:#[##] | 0 | 19 | > | RIP:list_lru_add | 0 | 19 | > | Kernel_panic-not_syncing:Fatal_exception | 0 | 19 | > +------------------------------------------+------------+------------+ > > > > [ 465.702558] BUG: unable to handle kernel NULL pointer dereference at 0000000000000000 > [ 465.721123] PGD 800000001740e067 P4D 800000001740e067 PUD 1740f067 PMD 0 > [ 465.737033] Oops: 0002 [#1] PTI > [ 465.744456] CPU: 0 PID: 163 Comm: rc.local Not tainted 4.16.0-rc5-mm1-00298-g42658d5 #1 > [ 465.760374] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 > [ 465.773920] RIP: 0010:list_lru_add+0x1e/0x70 > [ 465.780850] RSP: 0018:ffffc90001f0fe18 EFLAGS: 00010246 > [ 465.791551] RAX: ffff88001a1f16f0 RBX: ffff88000001a508 RCX: 0000000000000001 > [ 465.806362] RDX: 0000000000000000 RSI: ffff88000001a520 RDI: 0000000000000246 > [ 465.821265] RBP: ffffc90001f0fe28 R08: 0000000000000000 R09: 0000000000000001 > [ 465.836206] R10: ffffc90001f0fd88 R11: 0000000000000001 R12: ffff88001a1f16f0 > [ 465.850706] R13: ffffffff82c213d8 R14: ffffffff811aa4d5 R15: ffff88001a1f15f0 > [ 465.865285] FS: 00007fccddf45700(0000) GS:ffffffff82e3f000(0000) knlGS:0000000000000000 > [ 465.881839] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 465.893412] CR2: 0000000000000000 CR3: 0000000017868004 CR4: 00000000000206f0 > [ 465.907019] Call Trace: > [ 465.911369] d_lru_add+0x37/0x40 > [ 465.917037] dput+0x181/0x1d0 > [ 465.922225] __fput+0x1a7/0x1c0 > [ 465.928052] ____fput+0x9/0x10 > [ 465.933601] task_work_run+0x84/0xc0 > [ 465.940404] exit_to_usermode_loop+0x4e/0x80 > [ 465.948013] do_syscall_64+0x179/0x190 > [ 465.954817] entry_SYSCALL_64_after_hwframe+0x42/0xb7 > [ 465.963476] RIP: 0033:0x7fccdd625040 > [ 465.969435] RSP: 002b:00007fff689ff258 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 > [ 465.981362] RAX: 0000000000000000 RBX: 00000000006f1c08 RCX: 00007fccdd625040 > [ 465.993162] RDX: 00000000fbada408 RSI: 0000000000000001 RDI: 0000000000000003 > [ 466.005567] RBP: 0000000000000000 R08: 0000000000000078 R09: 0000000001000000 > [ 466.018316] R10: 0000000000000008 R11: 0000000000000246 R12: 0000000000000000 > [ 466.030899] R13: 000000000046e150 R14: 00000000000004f0 R15: 0000000000000001 > [ 466.043602] Code: c3 66 90 66 2e 0f 1f 84 00 00 00 00 00 55 48 89 e5 41 54 53 48 8b 1f 49 89 f4 48 89 df e8 db f6 f5 00 49 8b 04 24 49 39 c4 75 3d <48> c7 04 25 00 00 00 00 00 00 00 00 48 8b 43 50 48 8d 53 48 4c > [ 466.077316] RIP: list_lru_add+0x1e/0x70 RSP: ffffc90001f0fe18 > [ 466.087943] CR2: 0000000000000000 > [ 466.094137] ---[ end trace aeec590ab6dccbb2 ]--- > > > To reproduce: > > git clone https://github.com/intel/lkp-tests.git > cd lkp-tests > bin/lkp qemu -k <bzImage> job-script # job-script is attached in this email > > > > Thanks, > Xiaolong >