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From 6b7250b2393653e5d08deed591b78b41a2ee8d43 Mon Sep 17 00:00:00 2001
From: Eric Anholt <eric@anholt.net>
Date: Wed, 8 Feb 2017 15:00:54 -0800
Subject: [PATCH] drm/vc4: Fulfill user BO creation requests from the kernel BO
cache.
The from_cache flag was actually "the BO is invisible to userspace",
so we can repurpose to just zero out a cached BO and return it to
userspace.
Improves wall time for a loop of 5 glsl-algebraic-add-add-1 by
-1.44989% +/- 0.862891% (n=28, 1 outlier removed from each that
appeared to be other system noise)
Note that there's an intel-gpu-tools test to check for the proper
zeroing behavior here, which we continue to pass.
Signed-off-by: Eric Anholt <eric@anholt.net>
---
drivers/gpu/drm/vc4/vc4_bo.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)
--- a/drivers/gpu/drm/vc4/vc4_bo.c
+++ b/drivers/gpu/drm/vc4/vc4_bo.c
@@ -208,22 +208,23 @@ struct drm_gem_object *vc4_create_object
}
struct vc4_bo *vc4_bo_create(struct drm_device *dev, size_t unaligned_size,
- bool from_cache)
+ bool allow_unzeroed)
{
size_t size = roundup(unaligned_size, PAGE_SIZE);
struct vc4_dev *vc4 = to_vc4_dev(dev);
struct drm_gem_cma_object *cma_obj;
int pass, ret;
+ struct vc4_bo *bo;
if (size == 0)
return ERR_PTR(-EINVAL);
/* First, try to get a vc4_bo from the kernel BO cache. */
- if (from_cache) {
- struct vc4_bo *bo = vc4_bo_get_from_cache(dev, size);
-
- if (bo)
- return bo;
+ bo = vc4_bo_get_from_cache(dev, size);
+ if (bo) {
+ if (!allow_unzeroed)
+ memset(bo->base.vaddr, 0, bo->base.base.size);
+ return bo;
}
/* Otherwise, make a new BO. */
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