[PATCH 2/2] drm/amdgpu: bind GTT on demand

[Shawn Starr]

On Friday, September 23, 2016 4:55:33 PM EDT Andy Furniss wrote:
> Christian König wrote:
> > Am 22.09.2016 um 23:54 schrieb Andy Furniss:
> >> Marek Olšák wrote:
> >>> This breaks Tonga such that it hangs. Reproducible quickly with:
> >>> 
> >>> R600_DEBUG=testdma glxgears
> >>> 
> >>> It's a randomized test that runs forever. It should hang within 2
> >>> seconds.
> >> 
> >> So what is the status of this now?
> > 
> > The status is that I'm hammering my head on the desk for two weeks now
> > what the heck is going wrong here.
> 
> Oh, OK, I was just checking no one thought it was fixed really.
> 
> > What I've found so far is that a VM update command doesn't have the
> > result it should have, but I absolutely don't understand what happens
> > here.
> > 
> > The good news is that it's 100% reproducible and I already found and
> > fixed two bugs.
> > 
> > If you have any idea or more testing results what is going wrong here
> > please let me know.
> 
> I guess, you already did it anyway or it doesn't help, but
> 
> R600_DEBUG=testdma,check_vm glxgears
> 
> Does catch a vmfault and output to ddebug_dumps.
> It initially saves me from locking, though I will lock on repeated runs.
> 
> > If we can't fix this before the 4.9 release we are just going to revert
> > the patch causing this.
> > 
> > Regards,
> > Christian.
> > 

This is directly related to my thread on [amdgpu][CIK] drm-next-4.9-wip - 
piglit test - max-texture-size - GPU deadlock

Using Linus master kernel w/o drm-next-4.9-wip:
I cannot wedge GPU, the amdgpu kernel driver correctly throws 
errors if I've run out of memory vs crashing GPU.

as CIK doesn't have SDMA enabled in Mesa, I cannot reproduce Andy's test case, 
using max-texture-size can however.

Thanks,
Shawn

> >> R600_DEBUG=testdma glxgears isn't a test I've run on my r9285 tonga
> >> until I, by luck, saw this.
> >> 
> >> On agddf 4.9-wip at post time it did hang/reboot after 2 seconds.
> >> 
> >> On every update since it's still hung though now it takes longer.
> >> 
> >> Todays update tested both on head and reset on to the drm-next tag
> >> still hang.
> >> 
> >> Going back over older 4.9-wips it's one built on 26th August that is
> >> the first not to hang.
> >> 
> >> 
> >> 
> >> _______________________________________________
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> >> amd-gfx at lists.freedesktop.org
> >> https://lists.freedesktop.org/mailman/listinfo/amd-gfx
> 
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