#4604 Reduce draw distance when low on RAM

Author: akleshchev

indra/newview/llviewermessage.cpp

@@ -3364,6 +3364,15 @@ void send_agent_update(bool force_send, bool send_reliable)
     msg->addVector3Fast(_PREHASH_CameraUpAxis, LLViewerCamera::getInstance()->getUpAxis());
 
     static F32 last_draw_disatance_step = 1024;
+    F32 memory_limited_draw_distance = gAgentCamera.mDrawDistance;
+
+    if (LLViewerTexture::sDesiredDiscardBias > 2.f && LLViewerTexture::isSystemMemoryLow())
+    {
+        // If we are low on memory, reduce requested draw distace
+        F32 factor = 1.f + (LLViewerTexture::sDesiredDiscardBias - 2.f) / 3.f;
+        memory_limited_draw_distance = llmax(gAgentCamera.mDrawDistance / factor, gAgentCamera.mDrawDistance / 2.f);
+    }
+
     if (tp_state == LLAgent::TELEPORT_ARRIVING || LLStartUp::getStartupState() < STATE_MISC)
     {
         // Inform interest list, prioritize closer area.
@@ -3372,25 +3381,25 @@ void send_agent_update(bool force_send, bool send_reliable)
         // closer ones.
         // Todo: revise and remove once server gets distance sorting.
         last_draw_disatance_step = llmax((F32)(gAgentCamera.mDrawDistance / 2.f), 50.f);
+        last_draw_disatance_step = llmin(last_draw_disatance_step, memory_limited_draw_distance);
         msg->addF32Fast(_PREHASH_Far, last_draw_disatance_step);
     }
-    else if (last_draw_disatance_step < gAgentCamera.mDrawDistance)
+    else if (last_draw_disatance_step < memory_limited_draw_distance)
     {
         static LLFrameTimer last_step_time;
         if (last_step_time.getElapsedTimeF32() > 1.f)
         {
             // gradually increase draw distance
-            // Idealy this should be not per second, but based on how loaded
-            // mesh thread is, but hopefully this is temporary.
             last_step_time.reset();
-            F32 step = gAgentCamera.mDrawDistance * 0.1f;
-            last_draw_disatance_step = llmin(last_draw_disatance_step + step, gAgentCamera.mDrawDistance);
+            F32 step = memory_limited_draw_distance * 0.1f;
+            last_draw_disatance_step = llmin(last_draw_disatance_step + step, memory_limited_draw_distance);
         }
         msg->addF32Fast(_PREHASH_Far, last_draw_disatance_step);
     }
     else
     {
-        msg->addF32Fast(_PREHASH_Far, gAgentCamera.mDrawDistance);
+        last_draw_disatance_step = memory_limited_draw_distance;
+        msg->addF32Fast(_PREHASH_Far, memory_limited_draw_distance);
     }
 
     msg->addU32Fast(_PREHASH_ControlFlags, control_flags);

indra/newview/llviewertexture.cpp

@@ -527,8 +527,16 @@ void LLViewerTexture::updateClass()
 
     if (is_low && !was_low)
     {
-        // slam to 1.5 bias the moment we hit low memory (discards off screen textures immediately)
-        sDesiredDiscardBias = llmax(sDesiredDiscardBias, 1.5f);
+        if (is_sys_low)
+        {
+            // Not having system memory is more serious, so discard harder
+            sDesiredDiscardBias = llmax(sDesiredDiscardBias, 1.5f * getSystemMemoryBudgetFactor());
+        }
+        else
+        {
+            // Slam to 1.5 bias the moment we hit low memory (discards off screen textures immediately)
+            sDesiredDiscardBias = llmax(sDesiredDiscardBias, 1.5f);
+        }
 
         if (is_sys_low || over_pct > 2.f)
         { // if we're low on system memory, emergency purge off screen textures to avoid a death spiral
@@ -559,8 +567,13 @@ void LLViewerTexture::updateClass()
         sEvaluationTimer.reset();
 
         // lower discard bias over time when at least 10% of budget is free
-        const F32 FREE_PERCENTAGE_TRESHOLD = -0.1f;
-        if (sDesiredDiscardBias > 1.f && over_pct < FREE_PERCENTAGE_TRESHOLD)
+        constexpr F32 FREE_PERCENTAGE_TRESHOLD = -0.1f;
+        constexpr U32 FREE_SYS_MEM_TRESHOLD = 100;
+        static LLCachedControl<U32> min_free_main_memory(gSavedSettings, "RenderMinFreeMainMemoryThreshold", 512);
+        const S32Megabytes MIN_FREE_MAIN_MEMORY(min_free_main_memory() + FREE_SYS_MEM_TRESHOLD);
+        if (sDesiredDiscardBias > 1.f
+            && over_pct < FREE_PERCENTAGE_TRESHOLD
+            && getFreeSystemMemory() > MIN_FREE_MAIN_MEMORY)
         {
             static LLCachedControl<F32> high_mem_discard_decrement(gSavedSettings, "RenderHighMemMinDiscardDecrement", .1f);
 
@@ -627,24 +640,42 @@ void LLViewerTexture::updateClass()
 }
 
 //static
-bool LLViewerTexture::isSystemMemoryLow()
+U32Megabytes LLViewerTexture::getFreeSystemMemory()
 {
     static LLFrameTimer timer;
     static U32Megabytes physical_res = U32Megabytes(U32_MAX);
 
-    static LLCachedControl<U32> min_free_main_memory(gSavedSettings, "RenderMinFreeMainMemoryThreshold", 512);
-    const U32Megabytes MIN_FREE_MAIN_MEMORY(min_free_main_memory);
-
     if (timer.getElapsedTimeF32() < MEMORY_CHECK_WAIT_TIME) //call this once per second.
     {
-        return physical_res < MIN_FREE_MAIN_MEMORY;
+        return physical_res;
     }
 
     timer.reset();
 
     LLMemory::updateMemoryInfo();
     physical_res = LLMemory::getAvailableMemKB();
-    return physical_res < MIN_FREE_MAIN_MEMORY;
+    return physical_res;
+}
+
+//static
+bool LLViewerTexture::isSystemMemoryLow()
+{
+    static LLCachedControl<U32> min_free_main_memory(gSavedSettings, "RenderMinFreeMainMemoryThreshold", 512);
+    const U32Megabytes MIN_FREE_MAIN_MEMORY(min_free_main_memory);
+    return getFreeSystemMemory() < MIN_FREE_MAIN_MEMORY;
+}
+
+F32 LLViewerTexture::getSystemMemoryBudgetFactor()
+{
+    static LLCachedControl<U32> min_free_main_memory(gSavedSettings, "RenderMinFreeMainMemoryThreshold", 512);
+    const S32Megabytes MIN_FREE_MAIN_MEMORY(min_free_main_memory);
+    S32 free_budget = (S32Megabytes)getFreeSystemMemory() - MIN_FREE_MAIN_MEMORY;
+    if (free_budget < 0)
+    {
+        // should range from 1 to 2
+        return 1.f - free_budget / MIN_FREE_MAIN_MEMORY;
+    }
+    return 1.f;
 }
 
 //end of static functions

indra/newview/llviewertexture.h

@@ -115,6 +115,7 @@ class LLViewerTexture : public LLGLTexture
     static void initClass();
     static void updateClass();
     static bool isSystemMemoryLow();
+    static F32 getSystemMemoryBudgetFactor();
 
     LLViewerTexture(bool usemipmaps = true);
     LLViewerTexture(const LLUUID& id, bool usemipmaps) ;
@@ -189,6 +190,8 @@ class LLViewerTexture : public LLGLTexture
     friend class LLBumpImageList;
     friend class LLUIImageList;
 
+    static U32Megabytes getFreeSystemMemory();
+
 protected:
     friend class LLViewerTextureList;
     LLUUID mID;

indra/newview/llvocache.cpp

@@ -486,14 +486,20 @@ void LLVOCacheEntry::updateDebugSettings()
     //min radius: all objects within this radius remain loaded in memory
     static LLCachedControl<F32> min_radius(gSavedSettings,"SceneLoadMinRadius");
     static const F32 MIN_RADIUS = 1.0f;
-    const F32 draw_radius = gAgentCamera.mDrawDistance;
+
+    F32 draw_radius = gAgentCamera.mDrawDistance;
+    if (LLViewerTexture::sDesiredDiscardBias > 2.f && LLViewerTexture::isSystemMemoryLow())
+    {
+        F32 factor   = 1.f + (LLViewerTexture::sDesiredDiscardBias - 2.f) / 3.f;
+        draw_radius = llmax(2 * gAgentCamera.mDrawDistance / factor, draw_radius/2.f);
+    }
     const F32 clamped_min_radius = llclamp((F32) min_radius, MIN_RADIUS, draw_radius); // [1, mDrawDistance]
     sNearRadius = MIN_RADIUS + ((clamped_min_radius - MIN_RADIUS) * adjust_factor);
 
     // a percentage of draw distance beyond which all objects outside of view frustum will be unloaded, regardless of pixel threshold
     static LLCachedControl<F32> rear_max_radius_frac(gSavedSettings,"SceneLoadRearMaxRadiusFraction");
     const F32 min_radius_plus_one = sNearRadius + 1.f;
-    const F32 max_radius = rear_max_radius_frac * gAgentCamera.mDrawDistance;
+    const F32 max_radius = rear_max_radius_frac * draw_radius;
     const F32 clamped_max_radius = llclamp(max_radius, min_radius_plus_one, draw_radius); // [sNearRadius, mDrawDistance]
     sRearFarRadius = min_radius_plus_one + ((clamped_max_radius - min_radius_plus_one) * adjust_factor);