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/randomx/dataset.hpp

@@ -43,7 +43,7 @@ struct randomx_dataset {
 /* Global scope for C binding */
 struct randomx_cache {
 	uint8_t* memory = nullptr;
-	randomx::JitCompiler* jit;
+	randomx::JitCompiler* jit = nullptr;
 	randomx::CacheInitializeFunc* initialize;
 	randomx::DatasetInitFunc* datasetInit;
 	randomx::SuperscalarProgram programs[RANDOMX_CACHE_MAX_ACCESSES];

src/crypto/randomx/jit_compiler_a64.cpp

@@ -33,6 +33,8 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include "crypto/randomx/reciprocal.h"
 #include "crypto/randomx/virtual_memory.hpp"
 
+void randomx_set_huge_pages_jit(bool) {}
+
 namespace ARMV8A {
 
 constexpr uint32_t B           = 0x14000000;
@@ -89,7 +91,7 @@ static size_t CalcDatasetItemSize()
 
 constexpr uint32_t IntRegMap[8] = { 4, 5, 6, 7, 12, 13, 14, 15 };
 
-JitCompilerA64::JitCompilerA64()
+JitCompilerA64::JitCompilerA64(bool)
 	: code((uint8_t*) allocExecutableMemory(CodeSize + CalcDatasetItemSize()))
 	, literalPos(ImulRcpLiteralsEnd)
 	, num32bitLiterals(0)

src/crypto/randomx/jit_compiler_a64.hpp

@@ -46,7 +46,7 @@ namespace randomx {
 
 	class JitCompilerA64 {
 	public:
-		JitCompilerA64();
+		explicit JitCompilerA64(bool);
 		~JitCompilerA64();
 
 		void prepare() {}

src/crypto/randomx/jit_compiler_fallback.hpp

@@ -41,7 +41,7 @@ namespace randomx {
 
 	class JitCompilerFallback {
 	public:
-		JitCompilerFallback() {
+		explicit JitCompilerFallback(bool) {
 			throw std::runtime_error("JIT compilation is not supported on this platform");
 		}
 		void prepare() {}

src/crypto/randomx/jit_compiler_x86.cpp

@@ -49,6 +49,13 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #   include <cpuid.h>
 #endif
 
+static bool hugePagesJIT = false;
+
+void randomx_set_huge_pages_jit(bool hugePages)
+{
+	hugePagesJIT = hugePages;
+}
+
 namespace randomx {
 	/*
 
@@ -175,8 +182,9 @@ namespace randomx {
 #	endif
 
 	static std::atomic<size_t> codeOffset;
+	constexpr size_t codeOffsetIncrement = 59 * 64;
 
-	JitCompilerX86::JitCompilerX86() {
+	JitCompilerX86::JitCompilerX86(bool hugePagesEnable) {
 		BranchesWithin32B = xmrig::Cpu::info()->jccErratum();
 
 		int32_t info[4];
@@ -186,9 +194,11 @@ namespace randomx {
 		cpuid(0x80000001, info);
 		hasXOP = ((info[2] & (1 << 11)) != 0);
 
-		allocatedCode = (uint8_t*)allocExecutableMemory(CodeSize * 2);
+		allocatedCode = (uint8_t*)allocExecutableMemory(CodeSize * 2, hugePagesJIT && hugePagesEnable);
+
 		// Shift code base address to improve caching - all threads will use different L2/L3 cache sets
-		code = allocatedCode + (codeOffset.fetch_add(59 * 64) % CodeSize);
+		code = allocatedCode + (codeOffset.fetch_add(codeOffsetIncrement) % CodeSize);
+
 		memcpy(code, codePrologue, prologueSize);
 		if (hasXOP) {
 			memcpy(code + prologueSize, codeLoopLoadXOP, loopLoadXOPSize);
@@ -207,6 +217,7 @@ namespace randomx {
 	}
 
 	JitCompilerX86::~JitCompilerX86() {
+		codeOffset.fetch_sub(codeOffsetIncrement);
 		freePagedMemory(allocatedCode, CodeSize);
 	}
 

src/crypto/randomx/jit_compiler_x86.hpp

@@ -47,7 +47,7 @@ namespace randomx {
 
 	class JitCompilerX86 {
 	public:
-		JitCompilerX86();
+		explicit JitCompilerX86(bool hugePagesEnable);
 		~JitCompilerX86();
 		void prepare();
 		void generateProgram(Program&, ProgramConfiguration&, uint32_t);

src/crypto/randomx/randomx.cpp

@@ -381,7 +381,7 @@ extern "C" {
 					break;
 
 				case RANDOMX_FLAG_JIT:
-					cache->jit          = new randomx::JitCompiler();
+					cache->jit          = new randomx::JitCompiler(false);
 					cache->initialize   = &randomx::initCacheCompile;
 					cache->datasetInit  = cache->jit->getDatasetInitFunc();
 					cache->memory       = memory;

src/crypto/randomx/randomx.h

@@ -169,6 +169,7 @@ void randomx_apply_config(const T& config)
 }
 
 void randomx_set_scratchpad_prefetch_mode(int mode);
+void randomx_set_huge_pages_jit(bool hugePages);
 
 #if defined(__cplusplus)
 extern "C" {

src/crypto/randomx/virtual_memory.cpp

@@ -33,8 +33,8 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include "crypto/randomx/virtual_memory.hpp"
 
 
-void* allocExecutableMemory(std::size_t bytes) {
-    void *mem = xmrig::VirtualMemory::allocateExecutableMemory(bytes);
+void* allocExecutableMemory(std::size_t bytes, bool hugePages) {
+    void *mem = xmrig::VirtualMemory::allocateExecutableMemory(bytes, hugePages);
     if (mem == nullptr) {
         throw std::runtime_error("Failed to allocate executable memory");
     }

src/crypto/randomx/virtual_memory.hpp

@@ -30,6 +30,6 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #include <cstddef>
 
-void* allocExecutableMemory(std::size_t);
+void* allocExecutableMemory(std::size_t, bool);
 void* allocLargePagesMemory(std::size_t);
 void freePagedMemory(void*, std::size_t);

src/crypto/randomx/vm_compiled.hpp

@@ -58,7 +58,7 @@ namespace randomx {
 	protected:
 		void execute();
 
-		JitCompiler compiler;
+		JitCompiler compiler{ true };
 	};
 
 	using CompiledVmDefault = CompiledVm<1>;