Re: 2.4.17 agpgart process hang on crash

[Andrew Morton]

Lars Christensen wrote:
> 
> Hi. I have experienced a problem with the combination of kernel-2.4.16,
> the kernel agpgart module and NVIDIA supplied drivers. I don't know which
> is the cause of the problem.
> 
> Symptoms: Whenever an OpenGL application crashes (segfault etc.), the
> process hangs and can't be killed. Responds to no signals (not even 9). ps
> -ef hangs, it seems, when the crashed process is to be listed (some other
> processes are listed first).
> 
> Hardware: AMD Athlon 1.333HGZ, ASUS M266 motherboard (AMD761 AGP
> chipset), NVIDIA GeForce2 MX400 gfx card.
> 
> The mem=nopentium option have no effect on the problem, but it doesn't
> occur if I use the NVIDIA AGP drivers or kernel 2.4.16 agp drivers. I am
> not able to test the 2.4.17 agpgart with other 3D hardware that nvidia.
> 

This is possibly because the crashing application tries to dump
core, and the kernel gets a fault accessing the video card's
mapping, and deadlocks over the recursive attempt to take mmap_sem.

Please apply this patch:

	http://www.zip.com.au/~akpm/linux/2.4/2.4.18-pre7/fbmem-mmap.patch

and send a report back.

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