Hi, Back in 2012-2013, then-Intel employees Eric Anholt and Paul Berry wrote this threaded GL dispatch where GL calls are queued and executed in a different thread. It was supposed to deal with high CPU overhead of Mesa, but at the time most games used the compatibility profile and Steam didn't really exist on Linux, so it didn't help many (if any) apps.
Things are different today. We have Steam and most games use the GL core profile. We know of several games that have better performance with glthread, namely Borderlands 2, and some people reported to me that some other games also benefit. It's about time we put this into mainline Mesa. My plan is that we merge it as-is or with minor changes, and then we'll clean it up and improve it while it's in master. It's disabled by default, so it shouldn't bother anyone who doesn't want it. There is a drirc option to turn it on (just use the corresponding env var). All Gallium drivers support it. A note on synchronizations. Borderlands 2 has 170 thread syncs per frame. That means the app thread has to stop and wait 170x per frame. Despite that, it still has 70% higher performance in some cases. My theory is that if you have a lot of draw calls, you can have a lot of syncs, because the sheer amount of draw calls will just make those syncs irrelevant. 200 syncs per 4k draw calls is like 1 sync per 20 draw calls. Here it is: https://cgit.freedesktop.org/~mareko/mesa/log/?h=glthread The plan is to merge everything up to the gallium commit (without the Intel commits, I'll let Intel decide what to do with them). I can send the whole series to the list if that's preferable. Opinions? Marek _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
