drm/i915/gt: Clear the buffer pool age before use

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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: 06b73c2d0b ("drm/i915/gt: Delay taking the spinlock for grabbing from the buffer pool")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200915091417.4086-3-chris@chris-wilson.co.uk
(cherry picked from commit 9bb34ff25c)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

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Chris Wilson 2020-09-15 10:14:17 +01:00 • committed by Rodrigo Vivi

parent ba2ebf605d

commit 922d369b29

1 changed files with 2 additions and 0 deletions

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drivers/gpu/drm/i915/gt/intel_gt_buffer_pool.c

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