Re: [PATCH 07/16] drm/i915: Tidy generation of the GTT mmap offset

Joonas Lahtinen
2016-08-04T07:25:45Z

On ma, 2016-08-01 at 19:22 +0100, Chris Wilson wrote:
> If we make the observation that mmap-offsets are only released when we
> free an object, we can then deduce that the shrinker only creates free
> space in the mmap arena indirectly by flushing the request list and
> freeing expired objects. If we combine this with the lockless
> vma-manager and lockless idling, we can avoid taking our big struct_mutex
> until we need to actually free the requests.
>
> One side-effect is that we defer the madvise checking until we need the
> pages (i.e. the fault handler). This brings us into line with the other
> delayed checks (and madvise in general).
>
> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

Don't necessarily agree with all the "== 0", because it's in the
minority but;

Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

Regards, Joonas
--
Joonas Lahtinen
Open Source Technology Center
Intel Corporation