Bug 259756

Summary: GPUP WebGL in MiniBrowser still continuously allocates IOSurfaces
Product: WebKit Reporter: Kenneth Russell <kbr>
Component: WebGLAssignee: Nobody <webkit-unassigned>
Status: NEW ---    
Severity: Normal CC: dino, kbr, kkinnunen, webkit-bug-importer
Priority: P2 Keywords: InRadar
Version: WebKit Nightly Build   
Hardware: Unspecified   
OS: Unspecified   
Bug Depends on: 255860    
Bug Blocks: 267054    
Attachments:
Description Flags
Test case none

Description Kenneth Russell 2023-08-02 17:53:45 PDT 
Created attachment 467185 [details]
Test case

When MiniBrowser is run in WebKit2 mode with GPUP WebGL enabled, the attached test case causes IOSurfaces to be continuously allocated because they're in use too long. Increasing maxReusedDrawingBuffers in Source/WebCore/platform/graphics/cocoa/GraphicsContextGLCocoa.h causes the drawing buffers to be recycled. (Locally, I increased them to 6, but a smaller number would probably work.)

To reproduce:

1) Serve up the attached test case on localhost
2) Add an fprintf to stderr in this code which calls EGL_CreatePbufferFromClientBuffer:
https://github.com/WebKit/WebKit/blob/main/Source/WebCore/platform/graphics/cocoa/GraphicsContextGLCocoa.mm#L625
3) Tools/WebKit/build-webkit
4) Tools/WebKit/run-minibrowser

Note that there's a continuous stream of output.
Comment 1 Kenneth Russell 2023-08-02 17:54:52 PDT 
Note: discovered while investigating ANGLE/Metal issue in Chromium: crbug.com/1468346 .
Comment 2 Radar WebKit Bug Importer 2023-08-09 17:54:11 PDT 
<rdar://problem/113659847>