Actually, the problem was still there, but somehow I managed to get my computer into a condition in which the bug always occurs if I kept both iTune(playing) and a game open for 10-20 minutes. Those 2 programs was not necessarily needed for the bug, but
when they were left open for some time, the following symptoms would always show(every time out of 13ish):
"system interrupt" takes up 20~30% CPU time and it's neighbor "system and compressed memory" takes up 15~20%.
So I started uninstalling things, disabling services and disabling devices, several by several, see if I can stop it.
At a point I disabled all peripherals but lan interface(I needed network to start iTune and the game.) in bios, the bug was still there. Then I enabled everything but lan, and connected through wifi. Voila,
no bug for 6 hours now.
I don't really know what's the root cause of the problem, but the following statement seems to be true:
"In order for my computer to show the symptoms described above, lan interface must be enable."
Update:
A 1 Disable all offloads and unnecessary functions on Ethernet card helps.
2 Use specific drivers helps - Ethernet: 9.1.402.2015 provided by Realtek
Sound: 10.0.10586.0 provided by Microsoft
Nvidia Graphics: 353.62
3 Set up port isolation for MOD in ADSL modem so it doesn't broadcast MOD stream to all ports helps. Also reduces latency.
B If I cover my laptop free surfaces with wet tissue papers and blow them with fans to cool the laptop, A1 and A2 doesn't seem to matter and the computer works fine.
I think the problem starts when hardware reaches certain high temperature.