kernel_optimize_test/drivers/dma-buf
Chris Wilson 1cec20f0ea dma-buf: Restart reservation_object_wait_timeout_rcu() after writes
In order to be completely generic, we have to double check the read
seqlock after acquiring a reference to the fence. If the driver is
allocating fences from a SLAB_DESTROY_BY_RCU, or similar freelist, then
within an RCU grace period a fence may be freed and reallocated. The RCU
read side critical section does not prevent this reallocation, instead
we have to inspect the reservation's seqlock to double check if the
fences have been reassigned as we were acquiring our reference.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: linux-media@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: linaro-mm-sig@lists.linaro.org
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20160829070834.22296-8-chris@chris-wilson.co.uk
2016-10-12 19:57:14 +05:30
..
dma-buf.c dma-buf: Wait on the reservation object when sync'ing before CPU access 2016-08-16 12:31:35 +05:30
fence-array.c dma-buf: fix kernel-doc warning and typos 2016-08-17 09:19:28 +05:30
fence.c dma-buf/fence: make fence context 64 bit v2 2016-06-02 08:27:41 +02:00
Kconfig dma-buf/sync_file: improve Kconfig description for Sync Files 2016-07-13 19:52:08 +05:30
Makefile dma-buf/fence: add fence_array fences v6 2016-06-02 09:26:15 +02:00
reservation.c dma-buf: Restart reservation_object_wait_timeout_rcu() after writes 2016-10-12 19:57:14 +05:30
seqno-fence.c dma-buf: Minor coding style fixes 2015-05-21 11:29:59 +05:30
sync_file.c dma-buf/sync_file: free fences array in num_fences is 1 2016-09-22 04:06:16 -07:00