[Intel-gfx] Kswapd 100% CPU since 3.8 on Sandybridge

[Daniel Vetter]

On Sat, Oct 04, 2014 at 10:05:20AM -0700, Sarah A Sharp wrote:
> Please excuse the non-wrapped email. My personal system is currently
> b0rked, so I'm sending this in frustration from my phone.
> 
> My laptop is currently completely hosed. Disk light on full solid
> Mouse movement sluggish to the point of moving a couple cms per second.
> Firefox window greyed out but not OOM killed yet. When this behavior
> occurred in the past, if I ran top, I would see kswapd taking up 100% of
> one of my two CPUs.
> 
> If I can catch the system in time before mouse movement becomes too
> sluggish, closing the browser window will cause kswapd usage to drop, and
> the system goes back to a normal state. If I don't catch it in time, I
> can't even ssh into the box to kill Firefox because the login times out.
> Occasionally Firefox gets OOM killed, but most of the time I have to use
> sysreq keys to reboot the system.
> 
> This can be reproduced by using either Chrome or Firefox. Chrome fails
> faster. I'm not sure whether it's related to loading tabs with a bunch of
> images, maybe flash, but it takes around 10-15 tabs being open before it
> starts to fail. I can try to characterize it further.
> 
> System: Lenovo x220 Intel Sandy Bridge graphics
> Ubuntu 14.04 with edgers PPA for Mesa
> 3.16.3 kernel
> 
> Since around the 3.8 kernel time frame, I've been able to reproduce this
> behavior. I'm pretty sure it was a kernel change.

Hm, doesn't ring any bell for i915 bugs, but to make sure can you please
sample debugfs/dri/0/i915_gem_objects while things go south?

Thanks, Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch