Created attachment 116721 [details] dmesg.out I have starange issue with CPU load. After system is loaded by some proccess CPU still run on almost 100% usage. I can not determine what cause this usage, killing processes doesn't help. Attached is dmesg and mpstat -A outputs
Created attachment 116731 [details] mpstat
uname -a Linux kolombo 3.12.1-3-ARCH #1 SMP PREEMPT Tue Nov 26 11:17:02 CET 2013 x86_64 GNU/Linux Nothing interesting in logs.
Created attachment 116741 [details] cpu-freqinfo
cat /proc/cpuinfo processor : 0 vendor_id : GenuineIntel cpu family : 6 model : 37 model name : Intel(R) Core(TM) i5 CPU M 520 @ 2.40GHz stepping : 5 microcode : 0x2 cpu MHz : 1199.000 cache size : 3072 KB physical id : 0 siblings : 4 core id : 0 cpu cores : 2 apicid : 0 initial apicid : 0 fpu : yes fpu_exception : yes cpuid level : 11 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc aperfmperf pni pclmulqdq dtes64 monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr pdcm pcid sse4_1 sse4_2 popcnt aes lahf_lm ida arat dtherm tpr_shadow vnmi flexpriority ept vpid bogomips : 4789.06 clflush size : 64 cache_alignment : 64 address sizes : 36 bits physical, 48 bits virtual power management:
|Nothing in that seems to show 100% usage ?
I understand that according to mpstat or ps CPU load is not high and it all looks weird. But after some load such as playing some flash video in firefox my system becomes unresponsive and any task takes ~100% if CPU time on each core. Also just after load CPU load average is ~7 and isn't lower than 4. I also checked CPU temperature to ensure that cooling works fine and it is not hardware issue. I have attached sreenshot of htop output with shows high load and load average.
Created attachment 117381 [details] htop_screenshot
Steps to reproduce: 1. Run cpu_load.py for 5-10 minutes from multiprocessing import Pool def f(x): while True: x * x no_of_cpu_to_be_consumed = 4 p = Pool(processes=no_of_cpu_to_be_consumed) p.map(f, range(no_of_cpu_to_be_consumed)) 2. Kill load script `pkill -f cpu_load` 3. Verify `top` or `htop` info Actual Results: load avarage is not acceptably high CPU load on any active process is ~70% mpstat reports wrong CPU utilizzation system is unresponsive Please provide any additional information you need to investigate this issue.