Re: PROBLEM: i915 causes complete desktop freezes in 4.15-rc5

[Alexandru Chirvasitu <achirvasub@gmail.com>]

I've cloned your

https://anongit.freedesktop.org/git/drm-tip.git

and am now trying to build it (just the master; I haven't tried
previous commits). The build fails at the modules stage with

Makefile:1015: recipe for target 'drivers' failed
make: *** [drivers] Error 2

What is the earliest commit I can try to build so it will still
include the config options you mention?

I'm sure I'm just missing something obvious..

On Wed, Jan 03, 2018 at 12:49:10PM +0000, Chris Wilson wrote:
> Quoting Alexandru Chirvasitu (2018-01-03 00:14:38)
> > For comparison, here's another one produced by the same kernel, on the
> > same laptop, but a different hard drive.
> > 
> > The OS was installed on a USB stick that I'd boot the laptop off
> > of. Recently I started getting lags when copying to / from the stick,
> > so I moved the OS to an external SSD.
> > 
> > Everything else stayed the same, and booting the same kernel resulted
> > in the same type of freeze. 
> 
> I still have no explanation for how the use-after-free is possible here.
> The list iteration and destruction are both guarded by the struct_mutex.
> 
> However, we have just pushed some extra assertions into drm-tip,
> https://cgit.freedesktop.org/drm-tip If you could please compile and
> test a kernel built using that branch and enable
> CONFIG_DRM_I915_DEBUG_GEM (which depends on CONFIG_DRM_I915_WERROR). I'm
> hoping that will catch the culprit in the act.
> -Chris