Don't scan for something to decimate every frame. Actually costs perf.

GPU/GLES/TextureCache.cpp

@@ -38,6 +38,9 @@
 // Not used in lowmem mode.
 #define TEXTURE_SECOND_KILL_AGE 100
 
+// Try to be prime to other decimation intervals.
+#define TEXCACHE_DECIMATION_INTERVAL 13
+
 extern int g_iNumVideos;
 
 u32 RoundUpToPowerOf2(u32 v)
@@ -61,6 +64,7 @@ static inline u32 GetLevelBufw(int level, u32 texaddr) {
 
 TextureCache::TextureCache() : clearCacheNextFrame_(false), lowMemoryMode_(false), clutBuf_(NULL) {
 	lastBoundTexture = -1;
+	decimationCounter_ = TEXCACHE_DECIMATION_INTERVAL;
 	// This is 5MB of temporary storage. Might be possible to shrink it.
 	tmpTexBuf32.resize(1024 * 512);  // 2MB
 	tmpTexBuf16.resize(1024 * 512);  // 1MB
@@ -97,6 +101,12 @@ void TextureCache::Clear(bool delete_them) {
 
 // Removes old textures.
 void TextureCache::Decimate() {
+	if (--decimationCounter_ <= 0) {
+		decimationCounter_ = TEXCACHE_DECIMATION_INTERVAL;
+	} else {
+		return;
+	}
+
 	glBindTexture(GL_TEXTURE_2D, 0);
 	lastBoundTexture = -1;
 	int killAge = lowMemoryMode_ ? TEXTURE_KILL_AGE_LOWMEM : TEXTURE_KILL_AGE;

GPU/GLES/TextureCache.h

@@ -147,5 +147,7 @@ private:
 
 	u32 lastBoundTexture;
 	float maxAnisotropyLevel;
+
+	int decimationCounter_;
 };
 

GPU/GLES/TransformPipeline.cpp

@@ -55,6 +55,9 @@ enum {
 	TRANSFORMED_VERTEX_BUFFER_SIZE = 65536 * sizeof(TransformedVertex)
 };
 
+
+#define VERTEXCACHE_DECIMATION_INTERVAL 17
+
 inline float clamp(float in, float min, float max) { 
 	return in < min ? min : (in > max ? max : in); 
 }
@@ -70,6 +73,7 @@ TransformDrawEngine::TransformDrawEngine()
 		framebufferManager_(0),
 		numDrawCalls(0),
 		uvScale(0) {
+	decimationCounter_ = VERTEXCACHE_DECIMATION_INTERVAL;
 	// Allocate nicely aligned memory. Maybe graphics drivers will
 	// appreciate it.
 	// All this is a LOT of memory, need to see if we can cut down somehow.
@@ -1095,6 +1099,12 @@ void TransformDrawEngine::ClearTrackedVertexArrays() {
 }
 
 void TransformDrawEngine::DecimateTrackedVertexArrays() {
+	if (--decimationCounter_ <= 0) {
+		decimationCounter_ = VERTEXCACHE_DECIMATION_INTERVAL;
+	} else {
+		return;
+	}
+
 	int threshold = gpuStats.numFrames - VAI_KILL_AGE;
 	for (auto iter = vai_.begin(); iter != vai_.end(); ) {
 		if (iter->second->lastFrame < threshold) {

GPU/GLES/TransformPipeline.h

@@ -181,6 +181,8 @@ private:
 	DeferredDrawCall drawCalls[MAX_DEFERRED_DRAW_CALLS];
 	int numDrawCalls;
 
+	int decimationCounter_;
+
 	UVScale *uvScale;
 };