[sldev] Issues with TextureBuffer size

[Nicholaz Beresford]

Here is another patch for llviewerimage.cpp which addresses

https://jira.secondlife.com/browse/VWR-733
https://jira.secondlife.com/browse/VWR-778
https://jira.secondlife.com/browse/VWR-207

VWR-733 was tested by a couple of people with 512MB machines with good 
results
VWR-778 was tested by a friend on a unique 16MB vid ram machine with 
excellent results
VWR207 I did test the large memory size in the debugger with a 3GB 
memory and
3GB video size and it seemed to work.

Patch now also has linux filenames (based on 1.15.1.3)




-------------- next part --------------
--- linden-orig/indra/newview/llviewerimage.cpp	2007-05-14 16:47:26.000000000 +0200
+++ linden/indra/newview/llviewerimage.cpp	2007-05-19 23:54:06.578125000 +0200
@@ -121,7 +121,6 @@
  	sDefaultImagep = gImageList.getImage(IMG_DEFAULT, TRUE, TRUE);
 #endif
  	sSmokeImagep = gImageList.getImage(IMG_SMOKE, TRUE, TRUE);
-
 }
 
 // static
@@ -138,7 +137,6 @@
 // tuning params
 const F32 discard_bias_delta = .05f;
 const F32 discard_delta_time = 0.5f;
-const S32 min_non_tex_system_mem = (128<<20); // 128 MB
 // non-const (used externally
 F32 texmem_lower_bound_scale = 0.85f;
 F32 texmem_middle_bound_scale = 0.925f;
@@ -149,17 +147,77 @@
 	sBoundTextureMemory = LLImageGL::sBoundTextureMemory;
 	sTotalTextureMemory = LLImageGL::sGlobalTextureMemory;
 	sMaxBoundTextureMem = gImageList.getMaxResidentTexMem();
+
+
+	// PATCH [Nicholas Beresford]
+	//
+
 	
-	sMaxTotalTextureMem = sMaxBoundTextureMem * 2;
-	if (sMaxBoundTextureMem > 64000000)
+	// this is the size calculation a la LindenLab version 1.14/1.15
+	// (used against a temporary S64 maxtotal variable to adjust to large
+	// system memory sizes ... VWR-207)
+	S64 maxtotaltexturemem = sMaxBoundTextureMem * 2;
+	if (sMaxBoundTextureMem > 64000000) // 64mB
 	{
-		sMaxTotalTextureMem -= sMaxBoundTextureMem/4;
+		maxtotaltexturemem -= sMaxBoundTextureMem/4;
 	}
-	
-	if (sMaxTotalTextureMem > (S32)gSysMemory.getPhysicalMemory() - min_non_tex_system_mem)
+
+
+	//
+	// limit texture cache to leave enough memory for program and operating system and 
+	// avoid excess virtual memory swapping 
+	// VWR-733
+	//
+	const S32 megabytes= (1<<20);
+	S32 min_non_tex_system_mem = 128*megabytes;			// absolute minimum 128MB, leave this much memory for operating system and SL-viewer
+	S64 system_memory= gSysMemory.getPhysicalMemory();	// system_memory as S64 (was cast to S32 previously - VWR-207)
+
+	system_memory= 3*1024*(S64)megabytes;
+
+	// system memory reports slightly less than the ideal numbers, so use a factor of 0.9 to approx the value
+	// (this is safe because board memory is usually upgraded in larger increments and even in case of an 
+	// error, just more memory will be left to the system rather than being used for texturing)
+	#define SYSMEM_EQUAL_OR_HIGHER(x) (system_memory >= (U64)((F32)(x)*0.9f))
+
+	// calculate memory reserve depending on system memory
+	if (SYSMEM_EQUAL_OR_HIGHER(768*megabytes)) 	// systems with 768GB and more 
 	{
-		sMaxTotalTextureMem = (S32)gSysMemory.getPhysicalMemory() - min_non_tex_system_mem;
+		min_non_tex_system_mem= 512*megabytes;	// caps tex-mem to 256 on 768MB and 512 on 1GB machines
 	}
+	else
+	if (SYSMEM_EQUAL_OR_HIGHER(512*megabytes)) 	// systems with 512MB up to 768GB 
+	{
+		min_non_tex_system_mem= 384*megabytes;	// caps tex-mem to 128MB on 512MB machines
+	}
+	else 	// systems with less than 512MB (256MB, 384MB, etc.)
+	{
+		min_non_tex_system_mem= 192*megabytes;	// absolute minimum (caps tex-mem to 64MB on 256MB machines)
+	}
+
+
+	//	cap maxtotaltexturemem with system memory 
+	if (maxtotaltexturemem > (system_memory - min_non_tex_system_mem))	// PATCH: chged sysmem from (S32) to (S64)
+	{
+		maxtotaltexturemem = (system_memory - min_non_tex_system_mem);	// PATCH: chged sysmem from (S32) to (S64)
+	}
+
+	// allow for at least 64MB (more buffering for 16MB ram cards than in previous implementation)
+	// which results in vastly improved visual performance on low end cards
+	// VWR-778
+	if (maxtotaltexturemem < 64*megabytes)  
+	{										
+		maxtotaltexturemem = 64*megabytes;	
+	}
+	
+
+	// make sure maxtotalmem fits in S32 (avoiding upgrading member sMaxTotalTexture 
+	// to type S64 as texture buffer sizes of 2GB seem to be unlikely at the moment anyway)
+	// VWR-207
+	sMaxTotalTextureMem= (S32)llmin(maxtotaltexturemem, (S64)S32_MAX);
+
+	//
+	// ~PATCH
+	
 	
 	if (sBoundTextureMemory >= sMaxBoundTextureMem ||
 		sTotalTextureMemory >= sMaxTotalTextureMem)