Vary lua GC frequency based on load

spring · May 5, 2018 · 0e61b6f · 0e61b6f
1 parent 8968003
commit 0e61b6f
Show file tree

Hide file tree

Showing 3 changed files with 10 additions and 4 deletions.
diff --git a/rts/Lua/LuaAllocState.h b/rts/Lua/LuaAllocState.h
@@ -4,11 +4,14 @@
 #include <atomic>
 
 struct SLuaAllocState {
+	static constexpr uint32_t maxAllocedBytes = 768u * (1024u * 1024u);
 	std::atomic<uint64_t> allocedBytes;
 	std::atomic<uint64_t> numLuaAllocs;
 	std::atomic<uint64_t> luaAllocTime;
 	std::atomic<uint64_t> numLuaStates;
 };
 
+extern SLuaAllocState gLuaAllocState;
+
 #endif
 
diff --git a/rts/Lua/LuaHandle.cpp b/rts/Lua/LuaHandle.cpp
@@ -2474,6 +2474,10 @@ CONFIG(float, LuaGarbageCollectionTimeMult).defaultValue(5.0f).minimumValue(1.0f
 
 void CLuaHandle::CollectGarbage()
 {
+	// if memory load is smaller than 75% run the GC less frequently
+	if (guRNG.NextFloat() > (1.33f * float(gLuaAllocState.allocedBytes.load()) / float(SLuaAllocState::maxAllocedBytes)))
+		return;
+
 	lua_lock(L_GC);
 	SetHandleRunning(L_GC, true);
 

diff --git a/rts/lib/lua/include/LuaUser.cpp b/rts/lib/lua/include/LuaUser.cpp
@@ -177,11 +177,10 @@ const char* spring_lua_get_handle_name(lua_State* L)
 ///////////////////////////////////////////////////////////////////////////
 // Custom Memory Allocator
 //
-static constexpr uint32_t maxAllocedBytes = 768u * (1024u * 1024u);
 static constexpr const char* maxAllocFmtStr = "[%s][handle=%s][OOM] synced=%d {alloced,maximum}={%u,%u}bytes\n";
 
 // tracks allocations across all states
-static SLuaAllocState gLuaAllocState = {{0}, {0}, {0}, {0}};
+SLuaAllocState gLuaAllocState = {{0}, {0}, {0}, {0}};
 static SLuaAllocError gLuaAllocError = {};
 
 void spring_lua_alloc_log_error(const luaContextData* lcd)
@@ -198,7 +197,7 @@ void spring_lua_alloc_log_error(const luaContextData* lcd)
 		e.msgPtr = &e.msgBuf[0];
 
 	// append to buffer until it fills up or get_error is called
-	e.msgPtr += SNPRINTF(e.msgPtr, sizeof(e.msgBuf) - (e.msgPtr - &e.msgBuf[0]), fmt, __func__, lhn, lcd->synced, uint32_t(s.allocedBytes), maxAllocedBytes);
+	e.msgPtr += SNPRINTF(e.msgPtr, sizeof(e.msgBuf) - (e.msgPtr - &e.msgBuf[0]), fmt, __func__, lhn, lcd->synced, uint32_t(s.allocedBytes), SLuaAllocState::maxAllocedBytes);
 }
 
 void* spring_lua_alloc(void* ud, void* ptr, size_t osize, size_t nsize)
@@ -218,7 +217,7 @@ void* spring_lua_alloc(void* ud, void* ptr, size_t osize, size_t nsize)
 		return nullptr;
 	}
 
-	if ((nsize > osize) && (gLuaAllocState.allocedBytes.load() > maxAllocedBytes)) {
+	if ((nsize > osize) && (gLuaAllocState.allocedBytes.load() > SLuaAllocState::maxAllocedBytes)) {
 		// (re)allocation
 		// better kill Lua than whole engine; instant desync if synced handle
 		// NOTE: this will trigger luaD_throw, which calls exit(EXIT_FAILURE)