[Intel-gfx] [PATCH 04/39] drm/i915/gt: Clear the buffer pool age before use

[Matthew Auld]

On Wed, 26 Aug 2020 at 14:28, Chris Wilson <chris at chris-wilson.co.uk> wrote:
>
> If we create a new node, it is possible for the slab allocator to return
> us a recently freed node. If that node was just retired, it will retain
> the current jiffy as its node->age. There is then a miniscule window,
> where as that node is retired, it will appear on the free list with an
> incorrect age and be eligible for reuse by one thread, and then by a
> second thread as the correct node->age is written.
>
> Fixes: 8080ffd81600 ("drm/i915/gt: Delay taking the spinlock for grabbing from the buffer pool")
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld at intel.com>