[Bf-blender-cvs] [658fd8df0bd] master: Geometry Nodes: refactor multi-threading in field evaluation
Jacques Lucke
noreply at git.blender.org
Fri Nov 26 11:06:23 CET 2021
Commit: 658fd8df0bd2427cd77e7fc4bcca8a102f67b626
Author: Jacques Lucke
Date: Fri Nov 26 11:05:47 2021 +0100
Branches: master
https://developer.blender.org/rB658fd8df0bd2427cd77e7fc4bcca8a102f67b626
Geometry Nodes: refactor multi-threading in field evaluation
Previously, there was a fixed grain size for all multi-functions. That was
not sufficient because some functions could benefit a lot from smaller
grain sizes.
This refactors adds a new `MultiFunction::call_auto` method which has the
same effect as just calling `MultiFunction::call` but additionally figures
out how to execute the specific multi-function efficiently. It determines
a good grain size and decides whether the mask indices should be shifted
or not.
Most multi-function evaluations benefit from this, but medium sized work
loads (1000 - 50000 elements) benefit from it the most. Especially when
expensive multi-functions (e.g. noise) is involved. This is because for
smaller work loads, threading is rarely used and for larger work loads
threading worked fine before already.
With this patch, multi-functions can specify execution hints, that allow
the caller to execute it most efficiently. These execution hints still
have to be added to more functions.
Some performance measurements of a field evaluation involving noise and
math nodes, ordered by the number of elements being evaluated:
```
1,000,000: 133 ms -> 120 ms
100,000: 30 ms -> 18 ms
10,000: 20 ms -> 2.7 ms
1,000: 4 ms -> 0.5 ms
100: 0.5 ms -> 0.4 ms
```
===================================================================
M source/blender/functions/CMakeLists.txt
M source/blender/functions/FN_multi_function.hh
D source/blender/functions/FN_multi_function_parallel.hh
M source/blender/functions/FN_multi_function_params.hh
M source/blender/functions/FN_multi_function_procedure_executor.hh
M source/blender/functions/intern/field.cc
M source/blender/functions/intern/multi_function.cc
D source/blender/functions/intern/multi_function_parallel.cc
A source/blender/functions/intern/multi_function_params.cc
M source/blender/functions/intern/multi_function_procedure_executor.cc
M source/blender/nodes/geometry/nodes/node_geo_transfer_attribute.cc
M source/blender/nodes/shader/nodes/node_shader_tex_noise.cc
M source/blender/nodes/shader/nodes/node_shader_tex_voronoi.cc
===================================================================
diff --git a/source/blender/functions/CMakeLists.txt b/source/blender/functions/CMakeLists.txt
index 54670c0d1b3..63c11164275 100644
--- a/source/blender/functions/CMakeLists.txt
+++ b/source/blender/functions/CMakeLists.txt
@@ -34,7 +34,7 @@ set(SRC
intern/generic_virtual_vector_array.cc
intern/multi_function.cc
intern/multi_function_builder.cc
- intern/multi_function_parallel.cc
+ intern/multi_function_params.cc
intern/multi_function_procedure.cc
intern/multi_function_procedure_builder.cc
intern/multi_function_procedure_executor.cc
@@ -54,7 +54,6 @@ set(SRC
FN_multi_function_builder.hh
FN_multi_function_context.hh
FN_multi_function_data_type.hh
- FN_multi_function_parallel.hh
FN_multi_function_param_type.hh
FN_multi_function_params.hh
FN_multi_function_procedure.hh
diff --git a/source/blender/functions/FN_multi_function.hh b/source/blender/functions/FN_multi_function.hh
index 3059fe59ca7..af60e54808e 100644
--- a/source/blender/functions/FN_multi_function.hh
+++ b/source/blender/functions/FN_multi_function.hh
@@ -60,6 +60,7 @@ class MultiFunction {
{
}
+ void call_auto(IndexMask mask, MFParams params, MFContext context) const;
virtual void call(IndexMask mask, MFParams params, MFContext context) const = 0;
virtual uint64_t hash() const
@@ -110,6 +111,31 @@ class MultiFunction {
return *signature_ref_;
}
+ /**
+ * Information about how the multi-function behaves that help a caller to execute it efficiently.
+ */
+ struct ExecutionHints {
+ /**
+ * Suggested minimum workload under which multi-threading does not really help.
+ * This should be lowered when the multi-function is doing something computationally expensive.
+ */
+ int64_t min_grain_size = 10000;
+ /**
+ * Indicates that the multi-function will allocate an array large enough to hold all indices
+ * passed in as mask. This tells the caller that it would be preferable to pass in smaller
+ * indices. Also maybe the full mask should be split up into smaller segments to decrease peak
+ * memory usage.
+ */
+ bool allocates_array = false;
+ /**
+ * Tells the caller that every execution takes about the same time. This helps making a more
+ * educated guess about a good grain size.
+ */
+ bool uniform_execution_time = true;
+ };
+
+ ExecutionHints execution_hints() const;
+
protected:
/* Make the function use the given signature. This should be called once in the constructor of
* child classes. No copy of the signature is made, so the caller has to make sure that the
@@ -121,6 +147,8 @@ class MultiFunction {
BLI_assert(signature != nullptr);
signature_ref_ = signature;
}
+
+ virtual ExecutionHints get_execution_hints() const;
};
inline MFParamsBuilder::MFParamsBuilder(const MultiFunction &fn, int64_t mask_size)
diff --git a/source/blender/functions/FN_multi_function_parallel.hh b/source/blender/functions/FN_multi_function_parallel.hh
deleted file mode 100644
index 84c57efd434..00000000000
--- a/source/blender/functions/FN_multi_function_parallel.hh
+++ /dev/null
@@ -1,39 +0,0 @@
-/*
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version 2
- * of the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
- */
-
-#pragma once
-
-/** \file
- * \ingroup fn
- */
-
-#include "FN_multi_function.hh"
-
-namespace blender::fn {
-
-class ParallelMultiFunction : public MultiFunction {
- private:
- const MultiFunction &fn_;
- const int64_t grain_size_;
- bool threading_supported_;
-
- public:
- ParallelMultiFunction(const MultiFunction &fn, const int64_t grain_size);
-
- void call(IndexMask mask, MFParams params, MFContext context) const override;
-};
-
-} // namespace blender::fn
diff --git a/source/blender/functions/FN_multi_function_params.hh b/source/blender/functions/FN_multi_function_params.hh
index 5c7e75230f3..f4ddc4f2881 100644
--- a/source/blender/functions/FN_multi_function_params.hh
+++ b/source/blender/functions/FN_multi_function_params.hh
@@ -25,6 +25,8 @@
* the function. `MFParams` is then used inside the called function to access the parameters.
*/
+#include <mutex>
+
#include "BLI_resource_scope.hh"
#include "FN_generic_pointer.hh"
@@ -45,6 +47,9 @@ class MFParamsBuilder {
Vector<const GVVectorArray *> virtual_vector_arrays_;
Vector<GVectorArray *> vector_arrays_;
+ std::mutex mutex_;
+ Vector<std::pair<int, GMutableSpan>> dummy_output_spans_;
+
friend class MFParams;
MFParamsBuilder(const MFSignature &signature, const IndexMask mask)
@@ -62,8 +67,8 @@ class MFParamsBuilder {
template<typename T> void add_readonly_single_input_value(T value, StringRef expected_name = "")
{
- T *value_ptr = &scope_.add_value<T>(std::move(value));
- this->add_readonly_single_input(value_ptr, expected_name);
+ this->add_readonly_single_input(VArray<T>::ForSingle(std::move(value), min_array_size_),
+ expected_name);
}
template<typename T> void add_readonly_single_input(const T *value, StringRef expected_name = "")
{
@@ -254,20 +259,12 @@ class MFParams {
this->assert_correct_param(param_index, name, MFParamType::SingleOutput);
int data_index = builder_->signature_->data_index(param_index);
GMutableSpan span = builder_->mutable_spans_[data_index];
- if (span.is_empty()) {
- /* The output is ignored by the caller, but the multi-function does not handle this case. So
- * create a temporary buffer that the multi-function can write to. */
- const CPPType &type = span.type();
- void *buffer = builder_->scope_.linear_allocator().allocate(
- builder_->min_array_size_ * type.size(), type.alignment());
- if (!type.is_trivially_destructible()) {
- /* Make sure the temporary elements will be destructed in the end. */
- builder_->scope_.add_destruct_call(
- [&type, buffer, mask = builder_->mask_]() { type.destruct_indices(buffer, mask); });
- }
- span = GMutableSpan{type, buffer, builder_->min_array_size_};
+ if (!span.is_empty()) {
+ return span;
}
- return span;
+ /* The output is ignored by the caller, but the multi-function does not handle this case. So
+ * create a temporary buffer that the multi-function can write to. */
+ return this->ensure_dummy_single_output(data_index);
}
/**
@@ -356,6 +353,8 @@ class MFParams {
}
#endif
}
+
+ GMutableSpan ensure_dummy_single_output(int data_index);
};
} // namespace blender::fn
diff --git a/source/blender/functions/FN_multi_function_procedure_executor.hh b/source/blender/functions/FN_multi_function_procedure_executor.hh
index b12e3a91210..409a031e7ed 100644
--- a/source/blender/functions/FN_multi_function_procedure_executor.hh
+++ b/source/blender/functions/FN_multi_function_procedure_executor.hh
@@ -34,6 +34,9 @@ class MFProcedureExecutor : public MultiFunction {
MFProcedureExecutor(const MFProcedure &procedure);
void call(IndexMask mask, MFParams params, MFContext context) const override;
+
+ private:
+ ExecutionHints get_execution_hints() const override;
};
} // namespace blender::fn
diff --git a/source/blender/functions/intern/field.cc b/source/blender/functions/intern/field.cc
index 7934490a6d9..297df3c15cf 100644
--- a/source/blender/functions/intern/field.cc
+++ b/source/blender/functions/intern/field.cc
@@ -21,7 +21,6 @@
#include "BLI_vector_set.hh"
#include "FN_field.hh"
-#include "FN_multi_function_parallel.hh"
namespace blender::fn {
@@ -358,13 +357,8 @@ Vector<GVArray> evaluate_fields(ResourceScope &scope,
build_multi_function_procedure_for_fields(
procedure, scope, field_tree_info, varying_fields_to_evaluate);
MFProcedureExecutor procedure_executor{procedure};
- /* Add multi threading capabilities to the field evaluation. */
- const int grain_size = 10000;
- fn::ParallelMultiFunction parallel_procedure_executor{procedure_executor, grain_size};
- /* Utility variable to make easy to switch the executor. */
- const MultiFunction &executor_fn = parallel_procedure_executor;
- MFParamsBuilder mf_params{executor_fn, &mask};
+ MFParamsBuilder mf_params{procedure_executor, &mask};
MFContextBuilder mf_context;
/* Provide inputs to the procedure executor. */
@@ -405,7 +399,7 @@ Vector<GVArray> evaluate_fields(ResourceScope &scope,
mf_params.add_uninitialized_single_output(span);
}
- executor_fn.call(mask, mf_params, mf_context);
+ procedure_executor.call_auto(mask, mf_params, mf_context);
}
/* Evaluate constant fields if necessary. */
diff --git a/source/blender/functions/intern/multi_function.cc b/source/blender/functions/intern/multi_function.cc
index ee2c69068db..3e5539d4248 100644
--- a/source/blender/functions/intern/multi_function.cc
+++ b/source/blender/functions/intern/multi_function.cc
@@ -16,8 +16,141 @@
#include "FN_multi_function.hh"
+#include "BLI_task.hh"
+#include "BLI_threads.h"
+
namespace blender::fn {
+using ExecutionHints = MultiFunction::ExecutionHints;
+
+ExecutionHints MultiFunction::execution_hints() const
+{
+ return this->get_execution_hints();
+}
+
+ExecutionHints MultiFunction::get_execution_hints() const
+{
+ return ExecutionHints{};
+}
+
+static bool supports_threading_by_slicing_params(const MultiFunction &fn)
+{
+ for (const int i : fn.param_indices()) {
+ const MFParamType param_type = fn.param_type(i);
+ if (ELEM(param_type.interface_type(),
+ MFParamType::InterfaceType::Mutable,
+ MFParamType::InterfaceType::Outp
@@ Diff output truncated at 10240 characters. @@
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