FYI, we noticed the below changes on https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master commit 703fe6c5b0bd69fec6c71797e08321c9b91ff63d ("mm: add tracepoint for scanning pages") [ 33.273428] systemd-journald[108]: Vacuuming... [ 33.274160] systemd-journald[108]: Vacuuming done, freed 0 bytes [ 33.279091] systemd-journald[108]: Flushing /dev/kmsg... [ 33.282419] BUG: unable to handle kernel NULL pointer dereference at (null) [ 33.283466] IP: [<ffffffffa61ca6b8>] khugepaged_do_scan+0x7d0/0xf8e [ 33.284302] PGD 0 [ 33.284588] Oops: 0000 [#1] DEBUG_PAGEALLOC [ 33.285177] Modules linked in: [ 33.285586] CPU: 0 PID: 12 Comm: khugepaged Not tainted 4.3.0-rc2-00088-g703fe6c #1 [ 33.286527] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_083030-gandalf 04/01/2014 [ 33.287827] task: ffff8800382e2300 ti: ffff8800382e4000 task.ti: ffff8800382e4000 [ 33.288747] RIP: 0010:[<ffffffffa61ca6b8>] [<ffffffffa61ca6b8>] khugepaged_do_scan+0x7d0/0xf8e [ 33.289842] RSP: 0000:ffff8800382e7ce8 EFLAGS: 00010246 [ 33.290524] RAX: 0000000000000000 RBX: 0000000000000002 RCX: 0000000000000001 [ 33.291420] RDX: 0000000000000003 RSI: ffff880000000118 RDI: 800000000f2000e7 [ 33.292299] RBP: ffff8800382e7dd0 R08: ffff880000000000 R09: 0000000000000000 [ 33.293179] R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000 [ 33.294093] R13: ffff8800103610e8 R14: 00007f0c84600000 R15: 0000000000000000 [ 33.294978] FS: 0000000000000000(0000) GS:ffffffffa6d91000(0000) knlGS:0000000000000000 [ 33.295971] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 33.296694] CR2: 0000000000000000 CR3: 00000000005df000 CR4: 00000000000006b0 [ 33.297603] Stack: [ 33.297872] ffffffffa6f8cfd8 0000000000000000 ffff8800382e2300 ffff8800382e2300 [ 33.298857] ffff8800382e7d18 00001000a6011a97 ffff8800382e7d98 ffffffffa60bb15e [ 33.299845] ffff8800382e7d88 ffff880010373bf0 00000001012e2300 0000000000001000 [ 33.300869] Call Trace: [ 33.301191] [<ffffffffa60bb15e>] ? local_clock+0x32/0x34 [ 33.301865] [<ffffffffa60c97d1>] ? trace_hardirqs_on+0xd/0xf [ 33.302577] [<ffffffffa61caed1>] khugepaged+0x5b/0x497 [ 33.303233] [<ffffffffa67f2994>] ? __schedule+0xe07/0xfbf [ 33.303954] [<ffffffffa60c141e>] ? __wake_up_sync+0x12/0x12 [ 33.304664] [<ffffffffa61cae76>] ? khugepaged_do_scan+0xf8e/0xf8e [ 33.305426] [<ffffffffa60ac4e9>] kthread+0x13f/0x147 [ 33.306061] [<ffffffffa60ac3aa>] ? kthread_create_on_node+0x265/0x265 [ 33.306894] [<ffffffffa67fa36f>] ret_from_fork+0x3f/0x70 [ 33.307586] [<ffffffffa60ac3aa>] ? kthread_create_on_node+0x265/0x265 [ 33.308396] Code: 8b bd 58 ff ff ff e8 98 ed 62 00 49 63 c4 48 ff 04 c5 48 d4 14 a7 45 85 e4 74 10 48 8b 7d a0 48 8d 55 a8 4c 89 f6 e8 41 ea ff ff <49> 8b 07 48 c1 e8 2d 48 89 c2 48 c1 ea 07 48 8b 0c d5 80 ce 2d [ 33.311972] RIP [<ffffffffa61ca6b8>] khugepaged_do_scan+0x7d0/0xf8e [ 33.312783] RSP <ffff8800382e7ce8> [ 33.313221] CR2: 0000000000000000 [ 33.313666] ---[ end trace 0a7debb3a130caa5 ]--- [ 33.314261] Kernel panic - not syncing: Fatal exception Thanks, Ying Huang