RandomX: added huge-pages-jit config parameter

Set to false by default, gives 0.2% boost on Ryzen 7 3700X with 16 threads, but hashrate might be unstable on Ryzen between launches. Use with caution.

src/crypto/common/MemoryPool.cpp

@@ -47,7 +47,11 @@ xmrig::MemoryPool::MemoryPool(size_t size, bool hugePages, uint32_t node)
         return;
     }
 
-    m_memory = new VirtualMemory(size * pageSize, hugePages, false, false, node);
+    constexpr size_t alignment = 1 << 24;
+
+    m_memory = new VirtualMemory(size * pageSize + alignment, hugePages, false, false, node);
+
+    m_alignOffset = (alignment - (((size_t)m_memory->scratchpad()) % alignment)) % alignment;
 }
 
 
@@ -71,7 +75,7 @@ uint8_t *xmrig::MemoryPool::get(size_t size, uint32_t)
         return nullptr;
     }
 
-    uint8_t *out = m_memory->scratchpad() + m_offset;
+    uint8_t *out = m_memory->scratchpad() + m_alignOffset + m_offset;
 
     m_offset += size;
     ++m_refs;

src/crypto/common/MemoryPool.h

@@ -54,6 +54,7 @@ protected:
 private:
     size_t m_refs           = 0;
     size_t m_offset         = 0;
+    size_t m_alignOffset    = 0;
     VirtualMemory *m_memory = nullptr;
 };
 

src/crypto/common/VirtualMemory.h

@@ -61,7 +61,7 @@ public:
     static bool isHugepagesAvailable();
     static bool isOneGbPagesAvailable();
     static uint32_t bindToNUMANode(int64_t affinity);
-    static void *allocateExecutableMemory(size_t size);
+    static void *allocateExecutableMemory(size_t size, bool hugePages);
     static void *allocateLargePagesMemory(size_t size);
     static void *allocateOneGbPagesMemory(size_t size);
     static void destroy();

src/crypto/common/VirtualMemory_unix.cpp

@@ -63,7 +63,7 @@ bool xmrig::VirtualMemory::isOneGbPagesAvailable()
 }
 
 
-void *xmrig::VirtualMemory::allocateExecutableMemory(size_t size)
+void *xmrig::VirtualMemory::allocateExecutableMemory(size_t size, bool hugePages)
 {
 #   if defined(__APPLE__)
     void *mem = mmap(0, size, PROT_READ | PROT_WRITE | PROT_EXEC, MAP_PRIVATE | MAP_ANON, -1, 0);
@@ -77,7 +77,12 @@ void *xmrig::VirtualMemory::allocateExecutableMemory(size_t size)
     constexpr int flag_2mb = 0;
 #   endif
 
-    void *mem = mmap(0, align(size), PROT_READ | PROT_WRITE | PROT_EXEC, MAP_PRIVATE | MAP_ANONYMOUS | MAP_POPULATE | flag_2mb, -1, 0);
+    void *mem = nullptr;
+
+    if (hugePages) {
+        mem = mmap(0, align(size), PROT_READ | PROT_WRITE | PROT_EXEC, MAP_PRIVATE | MAP_ANONYMOUS | MAP_POPULATE | flag_2mb, -1, 0);
+    }
+
     if (!mem) {
         void *mem = mmap(0, size, PROT_READ | PROT_WRITE | PROT_EXEC, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
     }

src/crypto/common/VirtualMemory_win.cpp

@@ -162,9 +162,13 @@ bool xmrig::VirtualMemory::isOneGbPagesAvailable()
 }
 
 
-void *xmrig::VirtualMemory::allocateExecutableMemory(size_t size)
+void *xmrig::VirtualMemory::allocateExecutableMemory(size_t size, bool hugePages)
 {
-    void* result = VirtualAlloc(nullptr, align(size), MEM_COMMIT | MEM_RESERVE | MEM_LARGE_PAGES, PAGE_EXECUTE_READWRITE);
+    void* result = nullptr;
+
+    if (hugePages) {
+        result = VirtualAlloc(nullptr, align(size), MEM_COMMIT | MEM_RESERVE | MEM_LARGE_PAGES, PAGE_EXECUTE_READWRITE);
+    }
 
     if (!result) {
         result = VirtualAlloc(nullptr, size, MEM_COMMIT | MEM_RESERVE, PAGE_EXECUTE_READWRITE);