After approximately a few weeks ago, I’ve been experiencing one of the strangest issues since using openSUSE: While watching certain videos on Youtube under Firefox, there is a probability that the operating system will crash. This only seems to happen while watching certain videos… I can play some clips as much as I want and nothing happens, but if I play others the OS may crash typically somewhere between 2 and 10 minutes. What’s stranger is that there’s a completely different effect every time, and there is no single crash… the list of possible outcomes I’ve experienced so far includes:
The computer simply freezes: I can no longer move the mouse cursor, use any keys (including toggling the NumLock / CapsLock leds), etc. Strangely enough, the audio of the video continues to play, even if the image is frozen.
The machine reboots by itself. The screen suddenly goes black for a few seconds, then I seamlessly find myself at the BIOS startup screen. The power LED stays up and I don’t hear the typical “click” sound which normally occurs when you power off a computer… it acts as if software triggered.
I am logged out and immediately find myself in the login manager. It’s exactly as if I clicked the “log out” button, except I don’t press any keys nor have any applications that could automatically issue this command.
The Firefox process freezes, but with a bizarre side effect: Any process that tries to kill or create a new process from there on will itself freeze immediately! For example: If I open Konsole and type in “dolphin” to open the file manager, the cursor goes one line down and stays there… same thing if I try to kill a process with the kill command. If I try to start up a program from the kickoff launcher, plasmashell will freeze. If I try to launch something from krunner, krunner will freeze. I even logged off my normal user account, pressed control + alt + f1 to start a new runlevel, logged in as root, and tried to kill or start processes there… same thing.
In the best case scenario, Firefox simply crashes and I can start it back up again.
Note: I do not believe this to be caused by faulty hardware. I use many programs on this machine, including hardware intensive games… I do not experience such crashes with anything else. Also I’ve recently changed video cards, and moved from the r600 driver to radeonsi… I remember that the issue used to happen on the old one as well, although I think it stopped at some point, possible after a certain package update. I don’t use the proprietary video driver, and am running openSUSE Tumbleweed.
Many kinds of things, hardware and software related can cause what you describe although nowadays rarely.
Recommend you start by leaving top running in a console regularly so you can see resource utilization when the problem happens (assuming you’re not running full screen video, and that itself may be a major contributing cause).
See this wiki page I wrote how to interpret memory usage in top or running the free tool… And, you may also try running the command I give you at the bottom of that wiki page that clears your memory buffers prior to viewing your videos.
When the result was the process freeze I described, I did go into control + alt + f1 as root and run “top”. The CLI interface is a bit harder to distinguish so I might have missed some things, but nothing seemed undoubtedly out of the ordinary. I might take and post a photo of the screen next time this happens.
I’ll try to remember and startup top in bash as well as ksysguard, before watching Youtube. Might take a while to catch anything this way however, since the frozen processes result is rather rare… usually it’s an instant reboot or logout.
I have temperature and fan monitors installed: There is no overheating while watching Youtube, on either CPU / Chipset & Mobo / GPU. Also the computer never powers off, only reboots… without the power LED ever dropping or the typical click sound occurring, meaning it’s likely a software thing.
This took a while, but it seems I’ve finally found the bizarre cause: The problem apparently happens only when watching 1080p and / or 60FPS videos. It stopped occurring after I disabled webm support in my browser, and now watch videos through mp4 instead. In Firefox, you must go in about:config and disable media.mediasource.webm.enabled.
Does anyone know why this might be? Is there a vulnerability in the kernel or the free video drivers, which allows webm to cause kernel panics?
Speculating, there might be a problem with the player running in your FF.
First, I’ve found relatively few videos on Youtube are compiled to run at 1600pixel resolution, verify the option is avaiable and running as such using your Youtube video control buttons.
You might also try other browsers besides FF to see if it’s a FF specific problem.
Should already be the case, but try forcing HTML5 instead of Flash, or vice versa. You can do this by going to the Youtube HTML5 configuration page, and of course you will need a Flash plugin to play Flash https://www.youtube.com/html5
Marking this as Resolved; It appears the problem was not a bug in the Kernel or video driver. It had to do with my overclock settings! The memories were clocked slightly too high, which introduced a small probability that the system would crash precisely while watching 1080p / 60FPS videos. I lowered the RAM clocks in BIOS, and there has been no crash after 10 days of uptime now. It’s beyond me why a frequency setting would crash a machine only while watching Youtube, even after I had +4 days of uptime without problems… in any case, this wasn’t what I thought it was.
Over clocking is tricky, different apps use the CPU and memory differently so timing can be an issue in one and not in another. Video is going to hit sequential areas of memory very hard. With today’s hardware I see little reason to overclock since the speed up is generally marginal