From baf1c9d346b6d698fa76618d8a88935ce4dfb0c5 Mon Sep 17 00:00:00 2001
From: Egor Duplenskii <egor.duplensky@gmail.com>
Date: Mon, 11 Mar 2024 07:17:41 +0100
Subject: [PATCH] [CPU] Reduce overhead of the executor storage (#23307)

By using a vector instead of a map.
To reduce an overhead of selecting an executor.
Since we know the exact mapping beforehand (by implementation Id): every
executor corresponds to
a particular implementation.
---
 .../src/nodes/executors/executor_factory.hpp  | 50 ++++++++++++-------
 1 file changed, 31 insertions(+), 19 deletions(-)

diff --git a/src/plugins/intel_cpu/src/nodes/executors/executor_factory.hpp b/src/plugins/intel_cpu/src/nodes/executors/executor_factory.hpp
index 3faede7fcb8..4d927eabf6a 100644
--- a/src/plugins/intel_cpu/src/nodes/executors/executor_factory.hpp
+++ b/src/plugins/intel_cpu/src/nodes/executors/executor_factory.hpp
@@ -61,7 +61,8 @@ public:
           m_postOps(postOps),
           m_context(context),
           m_suitableImplementations(filter(m_attrs, m_postOps, descriptors, implementationPriority)),
-          m_implementationRequiresFallback(m_suitableImplementations.size(), true) {}
+          m_implementationRequiresFallback(m_suitableImplementations.size(), true),
+          m_executors(m_suitableImplementations.size()) {}
 
     /**
      * @brief Retrieves the proper memory descriptors based on the provided memory descriptors.
@@ -106,12 +107,8 @@ public:
      */
     void preconfigure(const MemoryArgs& memory) {
         executor::Config<Attrs> config{memoryDescsFromMemory(memory), m_attrs, m_postOps};
-        std::transform(m_suitableImplementations.begin(),
-                       m_suitableImplementations.end(),
-                       m_implementationRequiresFallback.begin(),
-                       [&config](const std::reference_wrapper<const ExecutorImplementation<Attrs>>& impl) {
-                           return impl.get().requiresFallback(config);
-                       });
+
+        cacheFallbackStatus(config);
 
         const size_t implId = select(memory, 0);
         const auto& impl = m_suitableImplementations[implId].get();
@@ -123,7 +120,7 @@ public:
             }
         }
 
-        (void)create(impl, memory, m_context);
+        (void)create(implId, memory, m_context);
     }
 
     /**
@@ -154,7 +151,7 @@ public:
                     return fallback<Attrs, NodeT>(config, *fallbackConfig, memory, m_context, impl.name());
                 }
             }
-            const auto executor = create(impl, memory, m_context);
+            const auto executor = create(implId, memory, m_context);
             if (!executor->update(memory)) {
                 return nullptr;
             }
@@ -181,6 +178,19 @@ private:
 
         return memoryDescs;
     }
+
+    /**
+     * @brief Caches the fallback status for each suitable implementation.
+     */
+    void cacheFallbackStatus(const executor::Config<Attrs>& config) {
+        std::transform(m_suitableImplementations.begin(),
+                       m_suitableImplementations.end(),
+                       m_implementationRequiresFallback.begin(),
+                       [&config](const std::reference_wrapper<const ExecutorImplementation<Attrs>>& impl) {
+                           return impl.get().requiresFallback(config);
+                       });
+    }
+
     /**
      * @brief Filters and retrieves suitable implementations based on the provided executor configuration.
      *
@@ -249,18 +259,19 @@ private:
         return std::distance(m_suitableImplementations.begin(), selectedImplementation);
     }
 
-    ExecutorPtr create(const ExecutorImplementation<Attrs>& impl,
+    ExecutorPtr create(const size_t implId,
                        const MemoryArgs& memory,
                        const ExecutorContext::CPtr context) {
-        DEBUG_LOG("Creating executor using implementation: ", impl.name());
-        const auto& executorId = std::make_pair(impl.type(), impl.operationType());
-        auto factoryIt = m_executors.find(executorId);
-        if (factoryIt == m_executors.end()) {
-            factoryIt =
-                m_executors.insert(std::make_pair(executorId, impl.create(m_attrs, m_postOps, memory, context))).first;
-        }
+        assert(implId < m_executors.size());
+        auto executor = m_executors[implId];
+        if (executor)
+            return executor;
 
-        return factoryIt->second;
+        assert(implId < m_suitableImplementations.size());
+        const auto& impl = m_suitableImplementations[implId].get();
+        DEBUG_LOG("Creating executor using implementation: ", impl.name());
+
+        return impl.create(m_attrs, m_postOps, memory, context);
     }
 
     const Attrs& m_attrs;
@@ -269,7 +280,8 @@ private:
     std::vector<std::reference_wrapper<const ExecutorImplementation<Attrs>>> m_suitableImplementations;
     // stores fallback status to avoid performing the check for every make() call
     std::vector<bool> m_implementationRequiresFallback;
-    std::map<std::pair<ExecutorType, OperationType>, ExecutorPtr> m_executors;
+    // executors cache
+    std::vector<ExecutorPtr> m_executors;
 };
 
 template <typename Attrs, typename NodeT>