On Wednesday, July 19, 2017 3:09:13 AM PDT Chris Wilson wrote:
> Borrow a trick from anv, and use the last known index for the bo to skip
> a search of the batch->exec_bo when adding a new relocation. In defence
> against the bo being used in multiple batches simultaneously, we check
> that this slot exists and points back to us.
>
> v2: Also update brw_batch_references()
> v3: Reset bo->index on creation (Daniel)
>
> Signed-off-by: Chris Wilson <ch...@chris-wilson.co.uk>
> Cc: Kenneth Graunke <kenn...@whitecape.org>
> Cc: Matt Turner <matts...@gmail.com>
> Cc: Jason Ekstrand <jason.ekstr...@intel.com>
> Cc: Daniel Vetter <daniel.vet...@ffwll.ch>
> ---
> src/mesa/drivers/dri/i965/brw_bufmgr.c | 1 +
> src/mesa/drivers/dri/i965/brw_bufmgr.h | 7 +++++++
> src/mesa/drivers/dri/i965/intel_batchbuffer.c | 18 ++++++++++++++++--
> 3 files changed, 24 insertions(+), 2 deletions(-)
>
> diff --git a/src/mesa/drivers/dri/i965/brw_bufmgr.c
> b/src/mesa/drivers/dri/i965/brw_bufmgr.c
> index 46da53d353..9723124e8d 100644
> --- a/src/mesa/drivers/dri/i965/brw_bufmgr.c
> +++ b/src/mesa/drivers/dri/i965/brw_bufmgr.c
> @@ -388,6 +388,7 @@ retry:
> p_atomic_set(&bo->refcount, 1);
> bo->reusable = true;
> bo->cache_coherent = bufmgr->has_llc;
> + bo->index = -1;
>
> pthread_mutex_unlock(&bufmgr->lock);
>
> diff --git a/src/mesa/drivers/dri/i965/brw_bufmgr.h
> b/src/mesa/drivers/dri/i965/brw_bufmgr.h
> index 6a6051bb71..5310e32ac3 100644
> --- a/src/mesa/drivers/dri/i965/brw_bufmgr.h
> +++ b/src/mesa/drivers/dri/i965/brw_bufmgr.h
> @@ -76,6 +76,13 @@ struct brw_bo {
> uint64_t offset64;
>
> /**
> + * Index of this buffer inside the batch, -1 when not in a batch. Note
> + * that a single buffer may be in multiple batches (contexts), the index
> + * only refers to its last use and should not be trusted!
> + */
How about:
/**
* The validation list index for this buffer, or -1 when not in a batch.
* Note that a single buffer may be in multiple batches (contexts), and
* this is a global field, which refers to the last batch using the BO.
* It should not be considered authoritative, but can be used to avoid a
* linear walk of the validation list in the common case by guessing that
* exec_bos[bo->index] == bo and confirming whether that's the case.
*/
With that,
Reviewed-by: Kenneth Graunke <kenn...@whitecape.org>
> + unsigned int index;
> +
> + /**
> * Boolean of whether the GPU is definitely not accessing the buffer.
> *
> * This is only valid when reusable, since non-reusable
> diff --git a/src/mesa/drivers/dri/i965/intel_batchbuffer.c
> b/src/mesa/drivers/dri/i965/intel_batchbuffer.c
> index 81cd578b28..a358269d9b 100644
> --- a/src/mesa/drivers/dri/i965/intel_batchbuffer.c
> +++ b/src/mesa/drivers/dri/i965/intel_batchbuffer.c
> @@ -515,12 +515,20 @@ throttle(struct brw_context *brw)
> }
> }
>
> +#define READ_ONCE(x) (*(volatile __typeof__(x) *)&(x))
> +
> static void
> add_exec_bo(struct intel_batchbuffer *batch, struct brw_bo *bo)
> {
> if (bo != batch->bo) {
> - for (int i = 0; i < batch->exec_count; i++) {
> - if (batch->exec_bos[i] == bo)
> + unsigned int index = READ_ONCE(bo->index);
> +
> + if (index < batch->exec_count && batch->exec_bos[index] == bo)
> + return;
> +
> + /* May have been shared between multiple active batches */
> + for (index = 0; index < batch->exec_count; index++) {
> + if (batch->exec_bos[index] == bo)
> return;
> }
>
> @@ -553,6 +561,7 @@ add_exec_bo(struct intel_batchbuffer *batch, struct
> brw_bo *bo)
> validation_entry->rsvd1 = 0;
> validation_entry->rsvd2 = 0;
>
> + bo->index = batch->exec_count;
> batch->exec_bos[batch->exec_count] = bo;
> batch->exec_count++;
> batch->aperture_space += bo->size;
> @@ -597,6 +606,7 @@ execbuffer(int fd,
> struct brw_bo *bo = batch->exec_bos[i];
>
> bo->idle = false;
> + bo->index = -1;
>
> /* Update brw_bo::offset64 */
> if (batch->exec_objects[i].offset != bo->offset64) {
> @@ -742,6 +752,10 @@ brw_batch_has_aperture_space(struct brw_context *brw,
> unsigned extra_space)
> bool
> brw_batch_references(struct intel_batchbuffer *batch, struct brw_bo *bo)
> {
> + unsigned int index = READ_ONCE(bo->index);
> + if (index < batch->exec_count && batch->exec_bos[index] == bo)
> + return true;
> +
> for (int i = 0; i < batch->exec_count; i++) {
> if (batch->exec_bos[i] == bo)
> return true;
>
signature.asc
Description: This is a digitally signed message part.
_______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
