One one machine (compulabs fit-pc4) I occationally get:
Uhhuh. NMI received for unknown reason 3c on CPU 0
Do you have a strange power saving mode enabled?
Dazed on confused, but trying to continue.
The machine keeps running fine. I have seen this twice. Once shortly after a power-up, and yesterday after 2 days uptime. I search the internet for this particular error but found nothing really useful. It could be faulty power supply, hardware watchdog, Radeon chipset, kernel bug, overheating, bad hardware, … It seems that there can be multiple causes but most have been fixed several years ago or was on different hardware.
The machine is located 8000km from me so it is limited how much tinkering I can do.
Does anyone have an idea if the NMI is harmless?
The machine is running OpenSuSE 13.1 with kernel 3.11.10
$ uname -a
Linux henrikhome 3.11.10-21-default #1 SMP Mon Jul 21 15:28:46 UTC 2014 (9a9565d) x86_64 x86_64 x86_64 GNU/Linux
$ dmesg
...
14.964064] nf_conntrack: automatic helper assignment is deprecated and it will be removed soon. Use the iptables CT target to attach helpers instead.
3853.149137] SFW2-INext-ACC-TCP IN=enp5s0 OUT= MAC=00:01:c0:15:ae:3b:90:72:40:05:a9:45:08:00 SRC=188.176.48.94 DST=172.16.2.22 LEN=60 TOS=0x00 PREC=0x20 TTL=48 ID=34195 PROTO=TCP SPT=55164 DPT=22 WINDOW=29200 RES=0x00 SYN URGP=0 OPT (020405B40402080AE951E4480000000001030307)
7135.649613] SFW2-INext-ACC-TCP IN=enp5s0 OUT= MAC=00:01:c0:15:ae:3b:90:72:40:05:a9:45:08:00 SRC=188.176.48.94 DST=172.16.2.22 LEN=60 TOS=0x00 PREC=0x20 TTL=49 ID=20221 PROTO=TCP SPT=55373 DPT=22 WINDOW=29200 RES=0x00 SYN URGP=0 OPT (020405B40402080AE983F8F80000000001030307)
7159.624617] SFW2-INext-ACC-TCP IN=enp5s0 OUT= MAC=00:01:c0:15:ae:3b:90:72:40:05:a9:45:08:00 SRC=188.176.48.94 DST=172.16.2.22 LEN=60 TOS=0x00 PREC=0x20 TTL=48 ID=25613 PROTO=TCP SPT=55374 DPT=22 WINDOW=29200 RES=0x00 SYN URGP=0 OPT (020405B40402080AE98456880000000001030307)
[60588.855243] perf samples too long (2523 > 2500), lowering kernel.perf_event_max_sample_rate to 50000
[66715.185111] SFW2-INext-ACC-TCP IN=enp5s0 OUT= MAC=00:01:c0:15:ae:3b:90:72:40:05:a9:45:08:00 SRC=188.176.48.94 DST=172.16.2.22 LEN=60 TOS=0x00 PREC=0x20 TTL=49 ID=57004 PROTO=TCP SPT=55733 DPT=22 WINDOW=29200 RES=0x00 SYN URGP=0 OPT (020405B40402080AED10F7430000000001030307)
[178550.813126] SFW2-INext-ACC-TCP IN=enp5s0 OUT= MAC=00:01:c0:15:ae:3b:04:0c:ce:df:86:72:08:00 SRC=172.16.2.21 DST=172.16.2.22 LEN=64 TOS=0x00 PREC=0x00 TTL=64 ID=11244 DF PROTO=TCP SPT=53005 DPT=22 WINDOW=65535 RES=0x00 SYN URGP=0 OPT (020405B4010303050101080A391C0BC00000000004020000)
[213146.728678] Uhhuh. NMI received for unknown reason 3c on CPU 0.
[213146.728825] Do you have a strange power saving mode enabled?
[213146.728935] Dazed and confused, but trying to continue
[234464.627528] SFW2-INext-ACC-TCP IN=enp5s0 OUT= MAC=00:01:c0:15:ae:3b:90:72:40:05:a9:45:08:00 SRC=93.167.50.108 DST=172.16.2.22 LEN=60 TOS=0x00 PREC=0x20 TTL=48 ID=15085 PROTO=TCP SPT=37655 DPT=22 WINDOW=29200 RES=0x00 SYN URGP=0 OPT (020405B40402080A07D7E4370000000001030307)
$ lspci
00:00.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 16h Processor Root Complex
00:01.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Kabini [Radeon HD 8210]
00:01.1 Audio device: Advanced Micro Devices, Inc. [AMD/ATI] Device 9840
00:02.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 16h Processor Function 0
00:02.1 PCI bridge: Advanced Micro Devices, Inc. [AMD] Family 16h Processor Functions 5:1
00:02.2 PCI bridge: Advanced Micro Devices, Inc. [AMD] Family 16h Processor Functions 5:1
00:02.4 PCI bridge: Advanced Micro Devices, Inc. [AMD] Family 16h Processor Functions 5:1
00:02.5 PCI bridge: Advanced Micro Devices, Inc. [AMD] Family 16h Processor Functions 5:1
00:10.0 USB controller: Advanced Micro Devices, Inc. [AMD] FCH USB XHCI Controller (rev 01)
00:11.0 SATA controller: Advanced Micro Devices, Inc. [AMD] FCH SATA Controller [AHCI mode] (rev 40)
00:12.0 USB controller: Advanced Micro Devices, Inc. [AMD] FCH USB OHCI Controller (rev 39)
00:12.2 USB controller: Advanced Micro Devices, Inc. [AMD] FCH USB EHCI Controller (rev 39)
00:13.0 USB controller: Advanced Micro Devices, Inc. [AMD] FCH USB OHCI Controller (rev 39)
00:13.2 USB controller: Advanced Micro Devices, Inc. [AMD] FCH USB EHCI Controller (rev 39)
00:14.0 SMBus: Advanced Micro Devices, Inc. [AMD] FCH SMBus Controller (rev 3a)
00:14.2 Audio device: Advanced Micro Devices, Inc. [AMD] FCH Azalia Controller (rev 02)
00:14.3 ISA bridge: Advanced Micro Devices, Inc. [AMD] FCH LPC Bridge (rev 11)
00:14.7 SD Host controller: Advanced Micro Devices, Inc. [AMD] FCH SD Flash Controller (rev 01)
00:18.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 16h Processor Function 0
00:18.1 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 16h Processor Function 1
00:18.2 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 16h Processor Function 2
00:18.3 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 16h Processor Function 3
00:18.4 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 16h Processor Function 4
00:18.5 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 16h Processor Function 5
02:00.0 Network controller: Realtek Semiconductor Co., Ltd. RTL8188CE 802.11b/g/n WiFi Adapter (rev 01)
04:00.0 Ethernet controller: Intel Corporation I211 Gigabit Network Connection (rev 03)
05:00.0 Ethernet controller: Intel Corporation I211 Gigabit Network Connection (rev 03)
# sysctl -a |fgrep watch
fs.epoll.max_user_watches = 694743
fs.inotify.max_user_watches = 65536
kernel.nmi_watchdog = 1
kernel.watchdog = 1
kernel.watchdog_thresh = 10
# head -27 /proc/cpuinfo
processor : 0
vendor_id : AuthenticAMD
cpu family : 22
model : 0
model name : AMD A4-1250 APU with Radeon(TM) HD Graphics
stepping : 1
microcode : 0x700010b
cpu MHz : 800.000
cache size : 1024 KB
physical id : 0
siblings : 2
core id : 0
cpu cores : 2
apicid : 0
initial apicid : 0
fpu : yes
fpu_exception : yes
cpuid level : 13
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt pdpe1gb rdtscp lm constant_tsc rep_good nopl nonstop_tsc extd_apicid aperfmperf eagerfpu pni pclmulqdq monitor ssse3 cx16 sse4_1 sse4_2 movbe popcnt aes xsave avx f16c lahf_lm cmp_legacy svm extapic cr8_legacy abm sse4a misalignsse 3dnowprefetch osvw ibs skinit wdt topoext perfctr_nb perfctr_l2 arat xsaveopt hw_pstate proc_feedback npt lbrv svm_lock nrip_save tsc_scale flushbyasid decodeassists pausefilter pfthreshold bmi1
bogomips : 1996.17
TLB size : 1024 4K pages
clflush size : 64
cache_alignment : 64
address sizes : 40 bits physical, 48 bits virtual
power management: ts ttp tm 100mhzsteps hwpstate [11]