[Intel-gfx] [PATCH 2/6] drm/i915: Replace PIN_NONFAULT with calls to PIN_NOEVICT

[Matthew Auld]

On Tue, 20 Aug 2019 at 15:28, Chris Wilson <chris at chris-wilson.co.uk> wrote:
>
> When under severe stress for GTT mappable space, the LRU eviction model
> falls off a cliff. We spend all our time scanning the much large
> non-mappable vma searching for something within the mappable zone we can
> evict. Turn this on its head by only using the full vma if it is already
> pinned in the mappable zone or there is sufficient *free* space to
> accommodate it(prioritizing speedy reuse). If there is not, immediately
> fall back to using small chunks (tilerow for GTT mmap, single pages for
> pwrite/relocation) and using random eviction before doing a full search.
>
> Testcase: igt/gem_concurrent_blt
> References: https://bugs.freedesktop.org/show_bug.cgi?id=110848
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld at intel.com>