2017-04-26 Christian König deathsimple@vodafone.de:
Am 26.04.2017 um 16:46 schrieb Andres Rodriguez:
When a timeout of zero is specified, the caller is only interested in the fence status.
In the current implementation, dma_fence_default_wait will always call schedule_timeout() at least once for an unsignaled fence. This adds a significant overhead to a fence status query.
Avoid this overhead by returning early if a zero timeout is specified.
v2: move early return after enable_signaling
Signed-off-by: Andres Rodriguez andresx7@gmail.com
Reviewed-by: Christian König christian.koenig@amd.com
pushed to drm-misc-next. Thanks all.
Gustavo
On 28 April 2017 at 07:27, Gustavo Padovan gustavo@padovan.org wrote:
2017-04-26 Christian König deathsimple@vodafone.de:
Am 26.04.2017 um 16:46 schrieb Andres Rodriguez:
When a timeout of zero is specified, the caller is only interested in the fence status.
In the current implementation, dma_fence_default_wait will always call schedule_timeout() at least once for an unsignaled fence. This adds a significant overhead to a fence status query.
Avoid this overhead by returning early if a zero timeout is specified.
v2: move early return after enable_signaling
Signed-off-by: Andres Rodriguez andresx7@gmail.com
Reviewed-by: Christian König christian.koenig@amd.com
pushed to drm-misc-next. Thanks all.
I don't see this patch in -rc2, where did it end up going?
Dave.
On Wed, May 24, 2017 at 09:47:49AM +1000, Dave Airlie wrote:
On 28 April 2017 at 07:27, Gustavo Padovan gustavo@padovan.org wrote:
2017-04-26 Christian König deathsimple@vodafone.de:
Am 26.04.2017 um 16:46 schrieb Andres Rodriguez:
When a timeout of zero is specified, the caller is only interested in the fence status.
In the current implementation, dma_fence_default_wait will always call schedule_timeout() at least once for an unsignaled fence. This adds a significant overhead to a fence status query.
Avoid this overhead by returning early if a zero timeout is specified.
v2: move early return after enable_signaling
Signed-off-by: Andres Rodriguez andresx7@gmail.com
Reviewed-by: Christian König christian.koenig@amd.com
pushed to drm-misc-next. Thanks all.
I don't see this patch in -rc2, where did it end up going?
Queued for 4.13. Makes imo sense since it's just a performance improvement, not a clear bugfix. But it's in your drm-next, so if you want to fast-track you can cherry-pick it over:
commit 03c0c5f6641533f5fc14bf4e76d2304197402552 Author: Andres Rodriguez andresx7@gmail.com Date: Wed Apr 26 10:46:20 2017 -0400
dma-buf: avoid scheduling on fence status query v2
Cheers, Daniel
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Gustavo Padovan