It is definitely not a heat-related issue, unless you genuinely have a defective unit. I used a fan to cool the smsc(network/usb) chip in question and I was able to reliably crash the Pi despite the surface of the chip being cool to the touch. I have fixed(for now; I will not rule out a hardware defect) the problem on my Pi.
For anyone still having this issue, please try one of these two solutions(I recommend solution 1):
Solution 1: In your /etc/sysctl.conf, put this at the bottom:
This allows smsc95xx turbo mode to have enough memory to do its thing without overflowing kernel mem and causing the crash. You may set this higher if you still have the problem, until it goes away. Don't set it too high though as this will restrict more memory from programs(though, not a lot; this solution reserves 8MB for the kernel).
Solution 2: In your /boot/cmdline.txt, put this at the beginning:
This disables the smsc95xx turbo mode(as far as I can tell, I don't know why the value must be N) which, when enabled, allows the network driver to send multiple frames at the same time. This can overflow the kernel memory and cause the crash. Disabling turbo mode may reduce network performance. This could be an acceptable tradeoff for some people.
I found that I could reliably crash my Pi by checking out the svn trunk of ioQuake3. To test this, cd into /tmp, and run this command(make sure you apt-get install subversion first):
Code: Select all
svn co svn://svn.icculus.org/quake3/trunk ioquake3
Try this test before and after you attempt one of the solutions above. If it crashes afterward, try the other solution. If they both fail to fix the problem, then you have another problem. This information comes from a bug on the Linaro Linux section of Launchpad: https://bugs.launchpad.net/linux-linaro/+bug/664477
I prefer to set the minimum kernel memory to 8192 so I can keep turbo mode, as I plan on doing a lot of network streaming with my Pi. I hope I helped a bit here. If I got any terminology or other information wrong, please correct me. I want to become more knowledgeable in this.