cc: Set the mapped memory reclaim limit for the renderer compositor on Android

content/renderer/render_widget.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/renderer/render_widget.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
 #include "base/logging.h"
@@ skipping 44 matching lines @@
 #include "ui/base/ui_base_switches.h"
 #include "ui/gfx/point.h"
 #include "ui/gfx/rect_conversions.h"
 #include "ui/gfx/size_conversions.h"
 #include "ui/gfx/skia_util.h"
 #include "ui/gl/gl_switches.h"
 #include "ui/surface/transport_dib.h"
 #include "webkit/renderer/compositor_bindings/web_rendering_stats_impl.h"
 
 #if defined(OS_ANDROID)
+#include "base/android/sys_utils.h"
 #include "content/renderer/android/synchronous_compositor_factory.h"
 #endif
 
 #if defined(OS_POSIX)
 #include "ipc/ipc_channel_posix.h"
 #include "third_party/skia/include/core/SkMallocPixelRef.h"
 #include "third_party/skia/include/core/SkPixelRef.h"
 #endif  // defined(OS_POSIX)
 
 #include "third_party/WebKit/public/web/WebWidget.h"
@@ skipping 565 matching lines @@
 
 GURL RenderWidget::GetURLForGraphicsContext3D() {
   return GURL();
 }
 
 bool RenderWidget::ForceCompositingModeEnabled() {
   return false;
 }
 
 scoped_ptr<cc::OutputSurface> RenderWidget::CreateOutputSurface(bool fallback) {
-  const CommandLine& command_line = *CommandLine::ForCurrentProcess();
 
 #if defined(OS_ANDROID)
-   if (SynchronousCompositorFactory* factory =
-       SynchronousCompositorFactory::GetInstance()) {
+  if (SynchronousCompositorFactory* factory =
+      SynchronousCompositorFactory::GetInstance()) {
     return factory->CreateOutputSurface(routing_id());
   }
 #endif
 
-  uint32 output_surface_id = next_output_surface_id_++;
-
   // Explicitly disable antialiasing for the compositor. As of the time of
   // this writing, the only platform that supported antialiasing for the
   // compositor was Mac OS X, because the on-screen OpenGL context creation
   // code paths on Windows and Linux didn't yet have multisampling support.
   // Mac OS X essentially always behaves as though it's rendering offscreen.
   // Multisampling has a heavy cost especially on devices with relatively low
   // fill rate like most notebooks, and the Mac implementation would need to
   // be optimized to resolve directly into the IOSurface shared between the
   // GPU and browser processes. For these reasons and to avoid platform
   // disparities we explicitly disable antialiasing.
   WebKit::WebGraphicsContext3D::Attributes attributes;
   attributes.antialias = false;
   attributes.shareResources = true;
   attributes.noAutomaticFlushes = true;
   attributes.depth = false;
   attributes.stencil = false;
+
+  const CommandLine& command_line = *CommandLine::ForCurrentProcess();
   if (command_line.HasSwitch(cc::switches::kForceDirectLayerDrawing))
     attributes.stencil = true;
+
   scoped_refptr<ContextProviderCommandBuffer> context_provider;
   if (!fallback) {
     context_provider = ContextProviderCommandBuffer::Create(
         CreateGraphicsContext3D(attributes));
   }
 
+  uint32 output_surface_id = next_output_surface_id_++;
   if (!context_provider.get()) {
     if (!command_line.HasSwitch(switches::kEnableSoftwareCompositing))
       return scoped_ptr<cc::OutputSurface>();
 
     scoped_ptr<cc::SoftwareOutputDevice> software_device(
         new CompositorSoftwareOutputDevice());
 
     return scoped_ptr<cc::OutputSurface>(new CompositorOutputSurface(
         routing_id(),
         output_surface_id,
@@ skipping 1821 matching lines @@
   if (CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kDisableGpuCompositing))
     return scoped_ptr<WebGraphicsContext3DCommandBufferImpl>();
   scoped_ptr<WebGraphicsContext3DCommandBufferImpl> context(
       new WebGraphicsContext3DCommandBufferImpl(
           surface_id(),
           GetURLForGraphicsContext3D(),
           RenderThreadImpl::current(),
           weak_ptr_factory_.GetWeakPtr()));
 
-  if (!context->InitializeWithDefaultBufferSizes(
+
+  // If we raster too fast we become upload bound, and pending
+  // uploads consume memory. For maximum upload throughput, we would
+  // want to allow for upload_throughput * pipeline_time of pending
+  // uploads, after which we are just wasting memory. Since we don't
+  // know our upload throughput yet, this just caps our memory usage.
+#if defined(OS_ANDROID)
+  size_t divider = 1;
+  if (base::android::SysUtils::IsLowEndDevice())
+    divider = 3;
+
+  // For reference Nexus10 can upload 1MB in about 2.5ms.
+  const size_t kMaxBytesUploadedPerMs = (2 * 1024 * 1024) / (5 * divider);
+#else
+  // For reference Chromebook Pixel can upload 1MB in about 0.5ms.
+  const size_t kMaxBytesUploadedPerMs = 1024 * 1024 * 2;
+#endif
+
+  // Deadline to draw a frame to achieve 60 frames per second.
+  const size_t kMillisecondsPerFrame = 16;
+  // Assuming a two frame deep pipeline between the CPU and the GPU.
+  const size_t kMaxTransferBufferUsageBytes =
+    2 * kMillisecondsPerFrame * kMaxBytesUploadedPerMs;
+
+  // We keep the MappedMemoryReclaimLimit the same as the upload limit
+  // to avoid unnecessarily stalling the compositor thread.
+  const size_t kMappedMemoryReclaimLimit = kMaxTransferBufferUsageBytes;
+
+  if (!context->Initialize(
           attributes,
           false /* bind generates resources */,
-          CAUSE_FOR_GPU_LAUNCH_WEBGRAPHICSCONTEXT3DCOMMANDBUFFERIMPL_INITIALIZE))
+          CAUSE_FOR_GPU_LAUNCH_WEBGRAPHICSCONTEXT3DCOMMANDBUFFERIMPL_INITIALIZE,
+          kDefaultCommandBufferSize,
+          kDefaultStartTransferBufferSize,
+          kDefaultMinTransferBufferSize,
+          kDefaultMaxTransferBufferSize,
+          kMappedMemoryReclaimLimit))
     return scoped_ptr<WebGraphicsContext3DCommandBufferImpl>();
   return context.Pass();
 }
 
 }  // namespace content