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| author | Maíra Canal <mcanal@igalia.com> | 2024-09-23 10:55:11 -0300 |
|---|---|---|
| committer | Maíra Canal <mcanal@igalia.com> | 2024-09-25 08:40:23 -0300 |
| commit | 8dd6074d4719644b676adf9f07d71292bee28e3a (patch) | |
| tree | af24c9340e1289bd7666672224951ed5479c477d | |
| parent | be431dfec976e553a08883e26d0d0cc2598a8dfa (diff) | |
| download | linux-8dd6074d4719644b676adf9f07d71292bee28e3a.tar.gz | |
drm/v3d: Reduce the alignment of the node allocation
Currently, we are using an alignment of 128 kB to insert a node, which
ends up wasting memory as we perform plenty of small BOs allocations
(<= 4 kB). We require that allocations are aligned to 128Kb so for any
allocation smaller than that, we are wasting the difference.
This implies that we cannot effectively use the whole 4 GB address space
available for the GPU in the RPi 4. Currently, we can allocate up to
32000 BOs of 4 kB (~140 MB) and 3000 BOs of 400 kB (~1,3 GB). This can be
quite limiting for applications that have a high memory requirement, such
as vkoverhead [1].
By reducing the page alignment to 4 kB, we can allocate up to 1000000 BOs
of 4 kB (~4 GB) and 10000 BOs of 400 kB (~4 GB). Moreover, by performing
benchmarks, we were able to attest that reducing the page alignment to
4 kB can provide a general performance improvement in OpenGL
applications (e.g. glmark2).
Therefore, this patch reduces the alignment of the node allocation to 4
kB, which will allow RPi users to explore the whole 4GB virtual
address space provided by the hardware. Also, this patch allow users to
fully run vkoverhead in the RPi 4/5, solving the issue reported in [1].
[1] https://github.com/zmike/vkoverhead/issues/14
Signed-off-by: Maíra Canal <mcanal@igalia.com>
Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240923141348.2422499-8-mcanal@igalia.com
| -rw-r--r-- | drivers/gpu/drm/v3d/v3d_bo.c | 2 | ||||
| -rw-r--r-- | drivers/gpu/drm/v3d/v3d_drv.h | 2 |
2 files changed, 1 insertions, 3 deletions
diff --git a/drivers/gpu/drm/v3d/v3d_bo.c b/drivers/gpu/drm/v3d/v3d_bo.c index ecb80fd75b1a0e..427a1c405b190f 100644 --- a/drivers/gpu/drm/v3d/v3d_bo.c +++ b/drivers/gpu/drm/v3d/v3d_bo.c @@ -123,7 +123,7 @@ v3d_bo_create_finish(struct drm_gem_object *obj) */ ret = drm_mm_insert_node_generic(&v3d->mm, &bo->node, obj->size >> V3D_MMU_PAGE_SHIFT, - GMP_GRANULARITY >> V3D_MMU_PAGE_SHIFT, 0, 0); + SZ_4K >> V3D_MMU_PAGE_SHIFT, 0, 0); spin_unlock(&v3d->mm_lock); if (ret) return ret; diff --git a/drivers/gpu/drm/v3d/v3d_drv.h b/drivers/gpu/drm/v3d/v3d_drv.h index 41b09c8288486c..82d6e869dd412e 100644 --- a/drivers/gpu/drm/v3d/v3d_drv.h +++ b/drivers/gpu/drm/v3d/v3d_drv.h @@ -19,8 +19,6 @@ struct clk; struct platform_device; struct reset_control; -#define GMP_GRANULARITY (128 * 1024) - #define V3D_MMU_PAGE_SHIFT 12 #define V3D_MAX_QUEUES (V3D_CPU + 1) |