Found a workaround: Forcing Mir to use swap interval zero whenever xmir_dri2_copy_region is used seems to solve the issue. Then we get one swap per xmir_dri2_copy_region.
Although it's not clear why that's required at all. You should be able to call xmir_dri2_copy_region many times before a swap happens and get smooth rendering as a result. It's also concerning that xmir_dri2_copy_region assumes EGL_BUFFER_PRESERVED and EGL_SWAP_BEHAVIOR_PRESERVED_BIT are always enabled and supported when it appears we haven't even tried to to set them yet. -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xorg-server in Ubuntu. https://bugs.launchpad.net/bugs/1511278 Title: Xmir -rootless: glmark2 (default GLX mode) judders badly in DRI2 mode To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg-server/+bug/1511278/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp