[Beignet] Unrecoverable system lockup when allocating too much memory

[Zou, Nanhai]

looks like something related to drm driver bo management.

dose 
export bo_reuse=0
help?

Thanks
Zou Nanhai


> -----Original Message-----
> From: Beignet [mailto:beignet-bounces at lists.freedesktop.org] On Behalf Of
> Rebecca N. Palmer
> Sent: Saturday, November 07, 2015 6:06 AM
> To: beignet at lists.freedesktop.org
> Subject: Re: [Beignet] Unrecoverable system lockup when allocating too much
> memory
> 
> > (The example in
> > https://bugs.launchpad.net/ubuntu/+source/pyopencl/+bug/1354086 no
> > longer hangs, so the "rapidly allocating and freeing pyopencl objects
> > doesn't actually free the memory" aspect has evidently been fixed, but
> > keeping too many objects for the available memory still does hang.
> 
> On further investigation, it isn't that simple:
> 
> -Create and keep (large_array_test.py): With swap, creates the objects in
> swap (becoming slow but not actually hanging), then errors out on trying to do
> arithmetic on them.  Without swap, errors out in object creation, but not
> before the kernel's OOM killer terminates a few pieces of the desktop
> (according to the log, it thinks my test is only using ~50MB, so it (like
> gnome-system-monitor) evidently can't see GPU memory use).
> -Rapid create-then-free (arraybug_test.py) using the result (naive
> pyopencl.clmath): Doesn't hang, but may segfault on exit.  (Kernel log:
> python3[8857]: segfault at 20 ip 00007fa5caac3c84 sp 00007ffca782b2a0 error
> 4 in libpthread-2.21.so[7fa5caaba000+18000] ; I can't be more specific because
> it doesn't crash under gdb).
> -Rapid create-then-free throwing away the result (this would be a bug in a real
> program, but probably shouldn't hang the entire system): With swap, starts
> using it, hence becoming slow but not actually hanging (though I haven't taken
> it to the point of actually filling the swap).
> Without swap, hangs (at least screen output does: desktop clock frozen, mouse
> pointer minimally responsive), with disk activity (!);
> Alt+SysRq+s,u,b restarts, but usually doesn't write the log).