Language Selection

English French German Italian Portuguese Spanish

How XMir and Mir fit together

Filed under
Software
Ubuntu

For Ubuntu 13.10, Canonical are proposing to use Mir by default. Of course, this requires a certain amount of replumbing. X would normally be responsible for doing things like setting up the screen and pushing the pixels out to the hardware, but this is now handled by Mir instead. Where a native X server would allocate a framebuffer in video memory and render into it, XMir asks Mir for a window corresponding to the size of the screen and renders into that and then simply asks Mir to display it. This step is actually more interesting than it sounds.

Unless you're willing to throw lots of CPU at them, unaccelerated graphics are slow. Even if you are, you're going to end up consuming more power for the same performance, so XMir would be impractical if it didn't provide access to accelerated hardware graphics functions. It makes use of the existing Xorg accelerated X drivers to do this, which is as simple as telling the drivers to render into the window that XMir requested from Mir rather than into the video framebuffer directly. In other words, when displaying through XMir, you're using exactly the same display driver stack as you would be if you were using Xorg. In theory you'd expect identical performance - in practice there's a 10-20% performance hit right now, but that's being actively worked on. Fullscreen 3D apps will also currently take a hit due to there being no support for skipping compositing, which is being fixed. XMir should certainly be capable of performing around as well as native X, but there's no reason for it to be any faster.

rest here




More in Tux Machines

OpenStack Juno is out, Debian (and Ubuntu Trusty ports) packages ready

This is just a quick announce: Debian packages for Juno are out. In fact, they were ready the day of the release, on the 16th of October. I uploaded it all (to Experimental) the same day, literally a few hours after the final released was git tagged. But I had no time to announce it. This week-end, I took the time to do an Ubuntu Trusty port, which I also publish (it’s just a mater of rebuilding all, and it should work out of the box). Here are the backports repositories. For Wheezy: deb http://archive.gplhost.com/debian juno-backports main deb http://archive.gplhost.com/debian juno main For trusty: deb http://archive.gplhost.com/debian trusty-juno-backports main Read more

Video: Systemd the Core OS (no coughing)

There has been so much negative stuff about systemd on teh Interwebs lately. It is so sad. Quite a few distros picked systemd because they liked a lot of the features it has. Why do the people who like systemd actually like it? Sure, if you look hard enough, you can find those answers... but I remembered a video where the man himself explains it. Read more

GParted 0.20 Improves Btrfs Support

GParted 0.20.0 is out today with a release that primarily improves Btrfs support. The improved Btrfs support comes via now handling support for resizing Btrfs file-systems that span multiple devices. GParted 0.20 also has GRUB2 restoration steps added to the help manual plus various translation updates. Read more

Ubuntu Touch RTM Update Is Out, Has Better Performance and Beautiful New Indicators

Ubuntu developers had some minor problems in the week before with all sorts of bugs that were popping out. They postponed the release of a new update for the Ubuntu Touch RTM and, at one point, they even got everyone to focus on fixing the problems and nothing else. Now they have a new version out and progress really shows. Users who already have Ubuntu Touch on their phones might have noticed that the number of features added to the system have diminished drastically, but that's the way it should be. The system is getting closer to its final stages and there is little reason to add new options now. The current form of the OS is not very far from the official release, so only fixes remain to be made. Read more