Re: [PATCH i-g-t] tests/gem_ppgtt: Check for vm leaks with flink and ppgtt

Chris Wilson
2015-04-20T15:01:38Z

On Mon, Apr 20, 2015 at 03:56:09PM +0100, Tvrtko Ursulin wrote:
> >Will take a bit of judicious planning (like doing a self-copy on the dst
> >first to make sure it bound ahead of the leak and not reallocating the
> >batch handle)
>
> Hm.. not bad!
>
> >Or alternatively, we know the name of the flinked object, so we can do
> >an explicit search! Ok, that seems more robust, but you do some sync
> >point in there (either gem_sync() every child before exit or
> >gem_quiescent_gpu()).
>
> Anything to avoid debugfs parsing I think. Well not anything, if
> exec[].offset is not retrievable from intel_batchbuffer helpers I'll
> reconsider it. Definitely need to at least count ppgtt sections
> since the IGT already failed (to fail) on one older kernel with the
> poor character counting approach.

With the libdrm interface, drm_intel_bo->offset will be kept up to date
with the post-execbuffer value. I'd suggest just using the rawer ioctl
wrappers for fine control, especially when allocating objects and
offsets.
-Chris

--
Chris Wilson, Intel Open Source Technology Centre