Kubuntu 15.10, about 3 day old installation on a new HP 15-f272wm laptop (4096mb sdram, Intel Pentium N3540) keeps freezing, relatively unpredictably. the mouse doesn't work, nor do any key combinations (alt+f1, ctrl-alt-esc, ctrl-esc, ctrl-alt-[fkey], ctrl-alt-del-[shift], etc., even power button unless held for powercycle hard reset)

I saved the kernel & system logs covering a couple times it happened, available here https://drive.google.com/file/d/0B6dsMhJQd1QtVmtmMW5tcTR6dEE/view?usp=sharing It happens most often when using chromium - i tried switching to firefox, but it still has happened 1 or 2 more times, though chrome seemed to trigger it more often, making me think maybe it's something about memory &/or GPU allocation under moderate-to-heavy system load.  

I tend to have 4-16 browser tabs open, often in 2-3 windows on 4 virtual desktops, along w/ Pycharm community edition & i make heavy use of yakuake dropdown terminal & custom keyboard shortcuts, if that matters

Reproducible: Sometimes

Steps to Reproduce:
1. Use computer for web browsing, python development, etc.
2. some point, between 8min & 8hours, the mouse will freeze  
3. it's completely frozen at this point

Actual Results:  
despite furious motions on the trackpad, alt+tab, & every other key combo i can think, no response at all. caps lock wont light up, etc. kernel seems totally unresponsible, though I haven't gotten sysreq magic key working to confirm extent of kernel lockup

Expected Results:  
system would let me run my applications; if application crashes, it should still be possible to change windows, enter virtual terminal, kill offending process, etc

i'm probably going to try installing kubuntu 15.04, because this problem almost makes my current setup worse than going back to windows