On 25.05.2022 11:59, Nirmoy Das wrote:
_i915_vma_move_to_active() can receive > 1 fences for
multiple batch buffers submission. Because dma_resv_add_fence()
can only accept one fence at a time, change _i915_vma_move_to_active()
to be aware of multiple fences so that it can add individual
fences to the dma resv object.
v6: fix multi-line comment.
v5: remove double fence reservation for batch VMAs.
v4: Reserve fences for composite_fence on multi-batch contexts and
also reserve fence slots to composite_fence for each VMAs.
v3: dma_resv_reserve_fences is not cumulative so pass num_fences.
v2: make sure to reserve enough fence slots before adding.
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/5614
Signed-off-by: Nirmoy Das <nirmoy.das@xxxxxxxxx>
---
.../gpu/drm/i915/gem/i915_gem_execbuffer.c | 3 +-
drivers/gpu/drm/i915/i915_vma.c | 48 +++++++++++--------
2 files changed, 30 insertions(+), 21 deletions(-)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
index b279588c0672..8880d38d36b6 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
@@ -1010,7 +1010,8 @@ static int eb_validate_vmas(struct i915_execbuffer *eb)
}
}
- err = dma_resv_reserve_fences(vma->obj->base.resv, 1);
+ /* Reserve enough slots to accommodate composite fences */
+ err = dma_resv_reserve_fences(vma->obj->base.resv, eb->num_batches);
if (err)
return err;
diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c
index 4f6db539571a..0bffb70b3c5f 100644
--- a/drivers/gpu/drm/i915/i915_vma.c
+++ b/drivers/gpu/drm/i915/i915_vma.c
@@ -23,6 +23,7 @@
*/
#include <linux/sched/mm.h>
+#include <linux/dma-fence-array.h>
#include <drm/drm_gem.h>
#include "display/intel_frontbuffer.h"
@@ -1823,6 +1824,21 @@ int _i915_vma_move_to_active(struct i915_vma *vma,
if (unlikely(err))
return err;
+ /*
+ * Reserve fences slot early to prevent an allocation after preparing
+ * the workload and associating fences with dma_resv.
+ */
+ if (fence && !(flags & __EXEC_OBJECT_NO_RESERVE)) {
+ struct dma_fence *curr;
+ int idx;
+
+ dma_fence_array_for_each(curr, idx, fence)
+ ;
This look little odd.
Maybe we could add helper to dma core to get fences count, different story.
Reviewed-by: Andrzej Hajda <andrzej.hajda@xxxxxxxxx>
Regards
Andrzej
+ err = dma_resv_reserve_fences(vma->obj->base.resv, idx);
+ if (unlikely(err))
+ return err;
+ }
+
if (flags & EXEC_OBJECT_WRITE) {
struct intel_frontbuffer *front;
@@ -1832,31 +1848,23 @@ int _i915_vma_move_to_active(struct i915_vma *vma,
i915_active_add_request(&front->write, rq);
intel_frontbuffer_put(front);
}
+ }
- if (!(flags & __EXEC_OBJECT_NO_RESERVE)) {
- err = dma_resv_reserve_fences(vma->obj->base.resv, 1);
- if (unlikely(err))
- return err;
- }
+ if (fence) {
+ struct dma_fence *curr;
+ enum dma_resv_usage usage;
+ int idx;
- if (fence) {
- dma_resv_add_fence(vma->obj->base.resv, fence,
- DMA_RESV_USAGE_WRITE);
+ obj->read_domains = 0;
+ if (flags & EXEC_OBJECT_WRITE) {
+ usage = DMA_RESV_USAGE_WRITE;
obj->write_domain = I915_GEM_DOMAIN_RENDER;
- obj->read_domains = 0;
- }
- } else {
- if (!(flags & __EXEC_OBJECT_NO_RESERVE)) {
- err = dma_resv_reserve_fences(vma->obj->base.resv, 1);
- if (unlikely(err))
- return err;
+ } else {
+ usage = DMA_RESV_USAGE_READ;
}
- if (fence) {
- dma_resv_add_fence(vma->obj->base.resv, fence,
- DMA_RESV_USAGE_READ);
- obj->write_domain = 0;
- }
+ dma_fence_array_for_each(curr, idx, fence)
+ dma_resv_add_fence(vma->obj->base.resv, curr, usage);
}
if (flags & EXEC_OBJECT_NEEDS_FENCE && vma->fence)
