[Intel-gfx] [PATCH] drm/i915: Don't pin LRC in GGTT when dumping in debugfs

[Daniel, Thomas]

> -----Original Message-----
> From: daniel.vetter at ffwll.ch [mailto:daniel.vetter at ffwll.ch] On Behalf Of
> Daniel Vetter
> Sent: Thursday, November 20, 2014 12:51 PM
> To: Chris Wilson; Daniel, Thomas; intel-gfx at lists.freedesktop.org; akash goel
> (akash.goels at gmail.com)
> Subject: Re: [Intel-gfx] [PATCH] drm/i915: Don't pin LRC in GGTT when
> dumping in debugfs
> 
> On Thu, Nov 20, 2014 at 1:28 PM, Chris Wilson <chris at chris-wilson.co.uk>
> wrote:
> >> Can you identify any situation where the pages may go away?
> >
> > Anytime you trigger an allocation, the system may reap any objects
> > pages. It will even steal the dev->struct_mutex. To protect against
> > the shrinker you have to call pin_pages(). Here, there are no
> > allocations inside the loop and so you don't need to worry about the
> > shrinker stealing your pages.
> 
> Hm actually I think better safe than sorry here. At least I have
> (again) completely forgotten about our dear shrinker ...
> -Daniel

Does this discussion count as a review?  What was the conclusion - do I need to make a version without pinning or is it better safe than sorry?

Cheers,
Thomas.


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