Looking at the layer tree here, we see that even though the visible region is only height=20, the texture is still allocated for h=480. Clean up the memory here. This only occurs if a thebes layer was first a certain height, then shrunk due to another optimization.

Still on it, waiting to finish fixing bug 917416.

Have a basic patch working that can detect when the visible region is smaller than the texture region. Have to figure out how to correctly invalidate a texture.

Patch that allocates a new buffer if the visible region * 2 < mBufferRect. Problem is we have an empty visible region and don't deallocate, so we force a paint for now. We see our layers before: I/Gecko ( 4789): ThebesLayerComposite (0x48ad2400) [shadow-visible=< (x=0, y=0, w=320, h=480); >] [visible=< (x=0, y=0, w=320, h=480); >] [opaqueContent] [valid=< (x=0, y=0, w=320, h=480); >] I/Gecko ( 4789): DeprecatedContentHostDoubleBuffered (0x45674900) [buffer-rect=(x=0, y=0, w=320, h=480)] [buffer-rotation=(x=0, y=0)] I/Gecko ( 4789): GrallocDeprecatedTextureHostOGL (0x4649e3c0) [size=(width=320, height=480)] [format=SurfaceFormat::B8G8R8X8] [flags=TEXTURE_USE_NEAREST_FILTER] I/Gecko ( 4789): GrallocDeprecatedTextureHostOGL (0x4649e440) [size=(width=320, height=480)] [format=SurfaceFormat::B8G8R8X8] [flags=TEXTURE_USE_NEAREST_FILTER] And After: I/Gecko ( 4789): ThebesLayerComposite (0x48ad2400) [shadow-visible=< (x=0, y=0, w=320, h=20); >] [visible=< (x=0, y=0, w=320, h=20); >] [opaqueContent] [valid=< (x=0, y=0, w=320, h=20); >] I/Gecko ( 4789): DeprecatedContentHostDoubleBuffered (0x45674900) [buffer-rect=(x=0, y=0, w=320, h=32)] [buffer-rotation=(x=0, y=0)] I/Gecko ( 4789): GrallocDeprecatedTextureHostOGL (0x45508b80) [size=(width=320, height=32)] [format=SurfaceFormat::B8G8R8X8] [flags=TEXTURE_USE_NEAREST_FILTER] I/Gecko ( 4789): GrallocDeprecatedTextureHostOGL (0x45508ac0) [size=(width=0, height=0)] [format=SurfaceFormat::UNKNOWN] [flags=TEXTURE_USE_NEAREST_FILTER] It takes a couple of composited frames before the change shows up though.

Thanks for the pointer on where to look. Looks like that was the right spot and we clean up the buffer in this case. However, it looked like the region to draw was always empty in this particular case, so we still have to go through one paint to clean up the buffer. Then the next paint we should bail out. Is this the right approach? Thanks!

Comment on attachment 8371204 [details] [diff] [review] bufferShrink.patch Review of attachment 8371204 [details] [diff] [review]: ----------------------------------------------------------------- ::: gfx/layers/RotatedBuffer.cpp @@ +513,5 @@ > FinalizeFrame(result.mRegionToDraw); > > + // Only bail out if we can reuse the buffer. Otherwise we can have empty > + // regions that still have buffers and we want to deallocate those. > + if (result.mRegionToDraw.IsEmpty() && canReuseBuffer) { Can we call Clear() here (if !canReuseBuffer) rather than going through the buffer allocation path with a 0 size? I think that would be more obvious. Also, please put this in a separate patch, since it's fairly distinct from the other change in this patch.

Thanks for the feedback. Updated the patch to only include the detection of a smaller region. Will spawn off a new bug to clean 0 drawing region buffers.

Carrying r+ from mattwoodrow.

Carrying r+ from mattwoodrow. Formatted for checkin-needed friendly.

Ryan, can you please back this out and leave closed? Thanks! For anyone else coming here, see https://bugzilla.mozilla.org/show_bug.cgi?id=974025#c9.