Passing the index of the target buffer via the reloc.target_handle is
marginally more efficient for the kernel (it can avoid some allocations,
and can use a direct lookup rather than a hash or search). It is also
useful for ourselves as we can use the index into our exec_bos for other
tasks.
v2: Only enable HANDLE_LUT if we can use BATCH_FIRST and thereby avoid
a post-processing loop to fixup the relocations.
v3: Move kernel probing from context creation to screen init.
Use batch->use_exec_lut as it more descriptive of what's going on (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_context.h | 1 +
src/mesa/drivers/dri/i965/intel_batchbuffer.c | 60 +++++++++++++++++----------
src/mesa/drivers/dri/i965/intel_screen.c | 20 +++++++++
src/mesa/drivers/dri/i965/intel_screen.h | 5 +++
4 files changed, 64 insertions(+), 22 deletions(-)
diff --git a/src/mesa/drivers/dri/i965/brw_context.h
b/src/mesa/drivers/dri/i965/brw_context.h
index ffe4792b73..62ce5e472c 100644
--- a/src/mesa/drivers/dri/i965/brw_context.h
+++ b/src/mesa/drivers/dri/i965/brw_context.h
@@ -452,6 +452,7 @@ struct intel_batchbuffer {
uint32_t state_batch_offset;
enum brw_gpu_ring ring;
+ bool use_exec_lut;
bool needs_sol_reset;
bool state_base_address_emitted;
diff --git a/src/mesa/drivers/dri/i965/intel_batchbuffer.c
b/src/mesa/drivers/dri/i965/intel_batchbuffer.c
index 065a9c1c0c..5f9639cd4d 100644
--- a/src/mesa/drivers/dri/i965/intel_batchbuffer.c
+++ b/src/mesa/drivers/dri/i965/intel_batchbuffer.c
@@ -62,8 +62,6 @@ intel_batchbuffer_init(struct intel_batchbuffer *batch,
struct brw_bufmgr *bufmgr,
bool has_llc)
{
- intel_batchbuffer_reset(batch, bufmgr, has_llc);
-
if (!has_llc) {
batch->cpu_map = malloc(BATCH_SZ);
batch->map = batch->cpu_map;
@@ -85,6 +83,16 @@ intel_batchbuffer_init(struct intel_batchbuffer *batch,
batch->state_batch_sizes =
_mesa_hash_table_create(NULL, uint_key_hash, uint_key_compare);
}
+
+ struct brw_context *brw = container_of(batch, brw, batch);
+ /* To use the LUT method for execbuf, we also require placing the batch
+ * first (to simplify our implementation). We require a kernel recent
+ * enough to always support EXEC_LUT_HANDLE, but we must check that
+ * the kernel supports EXEC_BATCH_FIRST.
+ */
+ batch->use_exec_lut = brw->screen->kerninfo.has_exec_batch_first;
+
+ intel_batchbuffer_reset(batch, bufmgr, has_llc);
}
#define READ_ONCE(x) (*(volatile __typeof__(x) *)&(x))
@@ -117,21 +125,12 @@ add_exec_bo(struct intel_batchbuffer *batch, struct
brw_bo *bo)
batch->exec_array_size * sizeof(batch->exec_objects[0]));
}
- struct drm_i915_gem_exec_object2 *validation_entry =
- &batch->exec_objects[batch->exec_count];
- validation_entry->handle = bo->gem_handle;
- if (bo == batch->bo) {
- validation_entry->relocation_count = batch->reloc_count;
- validation_entry->relocs_ptr = (uintptr_t) batch->relocs;
- } else {
- validation_entry->relocation_count = 0;
- validation_entry->relocs_ptr = 0;
- }
- validation_entry->alignment = bo->align;
- validation_entry->offset = bo->offset64;
- validation_entry->flags = bo->kflags;
- validation_entry->rsvd1 = 0;
- validation_entry->rsvd2 = 0;
+ struct drm_i915_gem_exec_object2 *exec =
+ memset(&batch->exec_objects[batch->exec_count], 0, sizeof(*exec));
+ exec->handle = bo->gem_handle;
+ exec->alignment = bo->align;
+ exec->offset = bo->offset64;
+ exec->flags = bo->kflags;
bo->index = batch->exec_count;
batch->exec_bos[batch->exec_count] = bo;
@@ -157,6 +156,11 @@ intel_batchbuffer_reset(struct intel_batchbuffer *batch,
}
batch->map_next = batch->map;
+ if (batch->use_exec_lut) {
+ add_exec_bo(batch, batch->bo);
+ assert(batch->bo->index == 0);
+ }
+
batch->reserved_space = BATCH_RESERVED;
batch->state_batch_offset = batch->bo->size;
batch->needs_sol_reset = false;
@@ -663,15 +667,25 @@ do_flush_locked(struct brw_context *brw, int in_fence_fd,
int *out_fence_fd)
} else {
flags |= I915_EXEC_RENDER;
}
+
if (batch->needs_sol_reset)
flags |= I915_EXEC_GEN7_SOL_RESET;
+ unsigned int index;
+ if (batch->use_exec_lut) {
+ flags |= I915_EXEC_BATCH_FIRST | I915_EXEC_HANDLE_LUT;
+ index = 0;
+ } else {
+ index = add_exec_bo(batch, batch->bo);
+ }
+
+ struct drm_i915_gem_exec_object2 *exec = &batch->exec_objects[index];
+ exec->relocation_count = batch->reloc_count;
+ exec->relocs_ptr = (uintptr_t) batch->relocs;
+
if (ret == 0) {
uint32_t hw_ctx = batch->ring == RENDER_RING ? brw->hw_ctx : 0;
- /* Add the batch itself to the end of the validation list */
- add_exec_bo(batch, batch->bo);
-
ret = execbuffer(dri_screen->fd, batch, hw_ctx,
4 * USED_BATCH(*batch),
in_fence_fd, out_fence_fd, flags);
@@ -798,8 +812,9 @@ __brw_emit_reloc(struct intel_batchbuffer *batch, uint32_t
batch_offset,
assert(_mesa_bitcount(write_domain) <= 1);
uint64_t offset64;
+ unsigned int index;
if (target != batch->bo) {
- unsigned int index = add_exec_bo(batch, target);
+ index = add_exec_bo(batch, target);
struct drm_i915_gem_exec_object2 *exec = &batch->exec_objects[index];
if (write_domain) {
@@ -816,6 +831,7 @@ __brw_emit_reloc(struct intel_batchbuffer *batch, uint32_t
batch_offset,
offset64 = exec->offset;
} else {
offset64 = target->offset64;
+ index = target->index;
}
struct drm_i915_gem_relocation_entry *reloc =
@@ -825,7 +841,7 @@ __brw_emit_reloc(struct intel_batchbuffer *batch, uint32_t
batch_offset,
reloc->offset = batch_offset;
reloc->delta = target_offset;
- reloc->target_handle = target->gem_handle;
+ reloc->target_handle = batch->use_exec_lut ? index : target->gem_handle;
reloc->read_domains = read_domains;
reloc->write_domain = write_domain;
reloc->presumed_offset = offset64;
diff --git a/src/mesa/drivers/dri/i965/intel_screen.c
b/src/mesa/drivers/dri/i965/intel_screen.c
index 7ccc1d34f0..99804c8329 100644
--- a/src/mesa/drivers/dri/i965/intel_screen.c
+++ b/src/mesa/drivers/dri/i965/intel_screen.c
@@ -51,6 +51,8 @@
#define DRM_FORMAT_MOD_LINEAR 0
#endif
+#define DBG_NO_EXEC_BATCH_FIRST 0
+
static const __DRIconfigOptionsExtension brw_config_options = {
.base = { __DRI_CONFIG_OPTIONS, 1 },
.xml =
@@ -1466,6 +1468,22 @@ intelDestroyBuffer(__DRIdrawable * driDrawPriv)
_mesa_reference_framebuffer(&fb, NULL);
}
+static bool
+test_has_exec_batch_first(struct intel_screen *screen)
+{
+ if (DBG_NO_EXEC_BATCH_FIRST)
+ return DBG_NO_EXEC_BATCH_FIRST < 0;
+
+ return intel_get_integer(screen, I915_PARAM_HAS_EXEC_BATCH_FIRST) > 0;
+}
+
+static void
+intel_get_kernel_info(struct intel_screen *screen,
+ struct intel_kernel_info *kerninfo)
+{
+ kerninfo->has_exec_batch_first = test_has_exec_batch_first(screen);
+}
+
static void
intel_detect_sseu(struct intel_screen *screen)
{
@@ -2097,6 +2115,8 @@ __DRIconfig **intelInitScreen2(__DRIscreen *dri_screen)
if (!gen_get_device_info(screen->deviceID, &screen->devinfo))
return NULL;
+ intel_get_kernel_info(screen, &screen->kerninfo);
+
if (!intel_init_bufmgr(screen))
return NULL;
diff --git a/src/mesa/drivers/dri/i965/intel_screen.h
b/src/mesa/drivers/dri/i965/intel_screen.h
index 0980c8f561..d88703b1e6 100644
--- a/src/mesa/drivers/dri/i965/intel_screen.h
+++ b/src/mesa/drivers/dri/i965/intel_screen.h
@@ -44,10 +44,15 @@
extern "C" {
#endif
+struct intel_kernel_info {
+ bool has_exec_batch_first;
+};
+
struct intel_screen
{
int deviceID;
struct gen_device_info devinfo;
+ struct intel_kernel_info kerninfo;
__DRIscreen *driScrnPriv;
--
2.13.3
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