If we're moving a bunch of buffers from the CPU domain to the GPU domain, and
we've already blown out the entire cache via a wbinvd, there is nothing more to
do.
With this and the previous patches, I am seeing a 3x FPS increase on a certain
benchmark which uses a giant 2d array texture. Unless I missed something in the
code, it should only effect non-LLC i915 platforms.
I haven't yet run any numbers for other benchmarks, nor have I attempted to
check if various conformance tests still pass.
NOTE: As mentioned in the previous patch, if one can easily obtain the largest
buffer and attempt to flush it first, the results would be even more desirable.
Cc: DRI Development <dri-devel at lists.freedesktop.org>
Signed-off-by: Ben Widawsky <ben at bwidawsk.net>
---
drivers/gpu/drm/i915/i915_drv.h | 3 ++-
drivers/gpu/drm/i915/i915_gem.c | 12 +++++-------
drivers/gpu/drm/i915/i915_gem_execbuffer.c | 8 +++++---
drivers/gpu/drm/i915/intel_lrc.c | 8 +++++---
4 files changed, 17 insertions(+), 14 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index d68c75f..fdb92a3 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2642,7 +2642,8 @@ static inline bool i915_stop_ring_allow_warn(struct
drm_i915_private *dev_priv)
}
void i915_gem_reset(struct drm_device *dev);
-bool i915_gem_clflush_object(struct drm_i915_gem_object *obj, bool force);
+enum drm_cache_flush
+i915_gem_clflush_object(struct drm_i915_gem_object *obj, bool force);
int __must_check i915_gem_object_finish_gpu(struct drm_i915_gem_object *obj);
int __must_check i915_gem_init(struct drm_device *dev);
int i915_gem_init_rings(struct drm_device *dev);
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index de241eb..3746738 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -3608,7 +3608,7 @@ err_unpin:
return vma;
}
-bool
+enum drm_cache_flush
i915_gem_clflush_object(struct drm_i915_gem_object *obj,
bool force)
{
@@ -3617,14 +3617,14 @@ i915_gem_clflush_object(struct drm_i915_gem_object *obj,
* again at bind time.
*/
if (obj->pages == NULL)
- return false;
+ return DRM_CACHE_FLUSH_NONE;
/*
* Stolen memory is always coherent with the GPU as it is explicitly
* marked as wc by the system, or the system is cache-coherent.
*/
if (obj->stolen || obj->phys_handle)
- return false;
+ return DRM_CACHE_FLUSH_NONE;
/* If the GPU is snooping the contents of the CPU cache,
* we do not need to manually clear the CPU cache lines. However,
@@ -3635,12 +3635,10 @@ i915_gem_clflush_object(struct drm_i915_gem_object *obj,
* tracking.
*/
if (!force && cpu_cache_is_coherent(obj->base.dev, obj->cache_level))
- return false;
+ return DRM_CACHE_FLUSH_NONE;
trace_i915_gem_object_clflush(obj);
- drm_clflush_sg(obj->pages);
-
- return true;
+ return drm_clflush_sg(obj->pages);
}
/** Flushes the GTT write domain for the object if it's dirty. */
diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index 0c25f62..e8eb9e9 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -827,7 +827,7 @@ i915_gem_execbuffer_move_to_gpu(struct intel_engine_cs
*ring,
{
struct i915_vma *vma;
uint32_t flush_domains = 0;
- bool flush_chipset = false;
+ enum drm_cache_flush flush_chipset = DRM_CACHE_FLUSH_NONE;
int ret;
list_for_each_entry(vma, vmas, exec_list) {
@@ -836,8 +836,10 @@ i915_gem_execbuffer_move_to_gpu(struct intel_engine_cs
*ring,
if (ret)
return ret;
- if (obj->base.write_domain & I915_GEM_DOMAIN_CPU)
- flush_chipset |= i915_gem_clflush_object(obj, false);
+ if (obj->base.write_domain & I915_GEM_DOMAIN_CPU &&
+ flush_chipset != DRM_CACHE_FLUSH_WBINVD) {
+ flush_chipset = i915_gem_clflush_object(obj, false);
+ }
flush_domains |= obj->base.write_domain;
}
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 89b5577..a6c6ebd 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -611,7 +611,7 @@ static int execlists_move_to_gpu(struct intel_ringbuffer
*ringbuf,
struct intel_engine_cs *ring = ringbuf->ring;
struct i915_vma *vma;
uint32_t flush_domains = 0;
- bool flush_chipset = false;
+ enum drm_cache_flush flush_chipset = DRM_CACHE_FLUSH_NONE;
int ret;
list_for_each_entry(vma, vmas, exec_list) {
@@ -621,8 +621,10 @@ static int execlists_move_to_gpu(struct intel_ringbuffer
*ringbuf,
if (ret)
return ret;
- if (obj->base.write_domain & I915_GEM_DOMAIN_CPU)
- flush_chipset |= i915_gem_clflush_object(obj, false);
+ if (obj->base.write_domain & I915_GEM_DOMAIN_CPU &&
+ flush_chipset != DRM_CACHE_FLUSH_WBINVD) {
+ flush_chipset = i915_gem_clflush_object(obj, false);
+ }
flush_domains |= obj->base.write_domain;
}
--
2.1.3
