<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"> <style type="text/css" style="display:none;"></style> </head> <body dir="ltr"> <div id="divtagdefaultwrapper" style="font-size:12pt;color:#000000;font-family:Calibri,Helvetica,sans-serif;" dir="ltr"> Operating System: Windows 10 64-Bit Mesa Version: 13.0.1 (though the same behavior is seen with the latest version) Renderer: llvmpipe I have an application with multiple OpenGL windows (which optionally uses mesa) which I am currently transitioning from a shared render context to multiple render contexts with list sharing. Due to this change, VAOs can no longer be shared between windows. I'm finding that when using a VAO (e.g. through DrawElements) built from shared resources (not only in that case, but even in that case) that there is a significant performance penalty the first time. Looking at the profile, it appears to be getting into the llvm pieces. I'm finding this a bit surprising since my view of a VAO was that is was more lightweight and thus didn't expect much overhead in creating a new VAO from existing resources (To be explicit, the penalty is not on VAO creation but on first time use). So some questions: <ol style="margin-bottom: 0px; margin-top: 0px;"> <li>Any insight into why this is occurring?</li><li>Any way to mitigate the symptoms?</li><li>Any possibility of fixing it in a future release?</li></ol> I'd appreciate any thoughts you can provide. Thanks, Rob Conde </div> </body> </html>