FYI, we noticed the following commit:

https://github.com/0day-ci/linux Thomas-Garnier/x86-KASLR-Fix-physical-memory-calculation-on-KASLR-memory-randomization/20160809-024226
commit 20067c4c139c7213205acd1c4b6f3e6d68327267 ("x86/KASLR: Fix physical memory calculation on KASLR memory randomization")

in testcase: boot

on test machine: 2 threads qemu-system-x86_64 -enable-kvm with 360M memory

caused below changes:


+------------------------------------------------------------------+------------+------------+
|                                                                  | a064fd509d | 20067c4c13 |
+------------------------------------------------------------------+------------+------------+
| boot_successes                                                   | 90         | 0          |
| boot_failures                                                    | 8          | 32         |
| invoked_oom-killer:gfp_mask=0x                                   | 8          |            |
| Mem-Info                                                         | 8          |            |
| Out_of_memory:Kill_process                                       | 8          |            |
| IP-Config:Auto-configuration_of_network_failed                   | 3          |            |
| Kernel_panic-not_syncing:Out_of_memory_and_no_killable_processes | 3          |            |
| kernel_BUG_at_arch/x86/mm/physaddr.c                             | 0          | 32         |
| invalid_opcode:#[##]SMP_DEBUG_PAGEALLOC                          | 0          | 32         |
| RIP:__phys_addr                                                  | 0          | 32         |
| Kernel_panic-not_syncing:Fatal_exception                         | 0          | 32         |
| backtrace:hpet_enable                                            | 0          | 32         |
| backtrace:hpet_time_init                                         | 0          | 32         |
| backtrace:x86_late_time_init                                     | 0          | 32         |
+------------------------------------------------------------------+------------+------------+



[    0.000000] ---------------------------------
[    0.000000] allocated 786432 bytes of page_ext
[    0.000000] ------------[ cut here ]------------
[    0.000000] kernel BUG at arch/x86/mm/physaddr.c:26!
[    0.000000] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC
[    0.000000] Modules linked in:
[    0.000000] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.8.0-rc1-00007-g20067c4 #1
[    0.000000] task: ffffffffaa615540 task.stack: ffffffffaa600000
[    0.000000] RIP: 0010:[<ffffffffa9c36d74>]  [<ffffffffa9c36d74>] __phys_addr+0x49/0x4d
[    0.000000] RSP: 0000:ffffffffaa603e50  EFLAGS: 00010287
[    0.000000] RAX: ffffefd2967dffff RBX: 00000000fed00000 RCX: ffffffff024000c0
[    0.000000] RDX: 0000000000000002 RSI: 0000000000001000 RDI: ffff8800967dffff
[    0.000000] RBP: ffffffffaa603e50 R08: 0000000000000000 R09: 0000000000000000
[    0.000000] R10: 0000000000000000 R11: ffffffffaa616050 R12: 0000000000000002
[    0.000000] R13: 0000000000001000 R14: ffffa9ddc0000000 R15: 0000000000000002
[    0.000000] FS:  0000000000000000(0000) GS:ffff982d94600000(0000) knlGS:0000000000000000
[    0.000000] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    0.000000] CR2: 00000000ffffffff CR3: 000000000c410000 CR4: 00000000000006b0
[    0.000000] Stack:
[    0.000000]  ffffffffaa603e80 ffffffffa9c35f8b ffff982d940093c0 00000000fed00000
[    0.000000]  0000000000001000 ffffa9ddc0000000 ffffffffaa603ef0 ffffffffa9c32b0a
[    0.000000]  8000000000000173 0000000000000400 ffffffffaaa2fdb2 00000000fed00000
[    0.000000] Call Trace:
[    0.000000]  [<ffffffffa9c35f8b>] kernel_map_sync_memtype+0x24/0xd0
[    0.000000]  [<ffffffffa9c32b0a>] __ioremap_caller+0x222/0x2b5
[    0.000000]  [<ffffffffaaa2fdb2>] ? hpet_enable+0x2b/0x280
[    0.000000]  [<ffffffffa9c32baf>] ioremap_nocache+0x12/0x14
[    0.000000]  [<ffffffffaaa2fdb2>] hpet_enable+0x2b/0x280
[    0.000000]  [<ffffffffaaa256bb>] hpet_time_init+0x9/0x19
[    0.000000]  [<ffffffffaaa2568b>] x86_late_time_init+0xa/0x11
[    0.000000]  [<ffffffffaaa20e38>] start_kernel+0x37a/0x3f0
[    0.000000]  [<ffffffffaaa20120>] ? early_idt_handler_array+0x120/0x120
[    0.000000]  [<ffffffffaaa2029e>] x86_64_start_reservations+0x29/0x2b
[    0.000000]  [<ffffffffaaa203a7>] x86_64_start_kernel+0x107/0x114
[    0.000000] Code: 48 39 c7 73 14 eb 24 48 03 05 b9 e2 9d 00 48 81 ff ff ff ff 3f 76 16 0f 0b 0f b6 0d 80 bb da 00 48 89 c2 48 d3 ea 48 85 d2 74 02 <0f> 0b 5d c3 b8 00 00 00 80 55 48 01 f8 48 3d ff ff ff 3f 48 89 
[    0.000000] RIP  [<ffffffffa9c36d74>] __phys_addr+0x49/0x4d
[    0.000000]  RSP <ffffffffaa603e50>
[    0.000000] ---[ end trace 0000000000000000 ]---
[    0.000000] Kernel panic - not syncing: Fatal exception


FYI, raw QEMU command line is:

	qemu-system-x86_64 -enable-kvm -kernel /pkg/linux/x86_64-randconfig-s5-08090447/gcc-6/20067c4c139c7213205acd1c4b6f3e6d68327267/vmlinuz-4.8.0-rc1-00007-g20067c4 -append 'ip=::::vm-vp-quantal-x86_64-39::dhcp root=/dev/ram0 user=lkp job=/lkp/scheduled/vm-vp-quantal-x86_64-39/boot-1-quantal-core-x86_64.cgz-20067c4c139c7213205acd1c4b6f3e6d68327267-20160809-113128-1yh2kxs-1.yaml ARCH=x86_64 kconfig=x86_64-randconfig-s5-08090447 branch=linux-devel/devel-hourly-2016080903 commit=20067c4c139c7213205acd1c4b6f3e6d68327267 BOOT_IMAGE=/pkg/linux/x86_64-randconfig-s5-08090447/gcc-6/20067c4c139c7213205acd1c4b6f3e6d68327267/vmlinuz-4.8.0-rc1-00007-g20067c4 max_uptime=600 RESULT_ROOT=/result/boot/1/vm-vp-quantal-x86_64/quantal-core-x86_64.cgz/x86_64-randconfig-s5-08090447/gcc-6/20067c4c139c7213205acd1c4b6f3e6d68327267/0 LKP_SERVER=inn 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 systemd.log_level=err ignore_loglevel earlyprintk=ttyS0,115200 console=ttyS0,115200 console=tty0 vga=normal rw drbd.minor_count=8'  -initrd /fs/sdc1/initrd-vm-vp-quantal-x86_64-39 -m 360 -smp 2 -device e1000,netdev=net0 -netdev user,id=net0 -boot order=nc -no-reboot -watchdog i6300esb -watchdog-action debug -rtc base=localtime -pidfile /dev/shm/kboot/pid-vm-vp-quantal-x86_64-39 -serial file:/dev/shm/kboot/serial-vm-vp-quantal-x86_64-39 -daemonize -display none -monitor null 





Thanks,
Xiaolong