GSoC summary #1 - July 29
The current implementation of X Window System relies in a signal scheme to manage the input event coming from hardware devices. This scheme frequently get blocked when lot of IO is occurring (for instance, when the process is swapping in/out). Get blocked means for instance a jumping cursor on the screen and in GUI is always desirable to prioritize the system responsiveness for end users. The human/computer interface should be smooth and this is the most user visible aspect of a system.
The current DRM kernel modesetting tree is already taking care to update the cursor registers and paint it to the screen. Very cool [0].
What I’ve done today is a shortcut between the kernel input layer and DRM to update the cursor directly on screen without the X server be notified always. Of course, a lot of issues raised up together. So let’s try to delegates the tasks again.
For my SoC project I need some mechanism to evaluate the improvement of the input thread inside X. So I wrote a simple kernel driver that emulates the mouse device moving and emitting bits of a simple pattern. I don’t know if something like this already exists or if there are other ways to do it, but the fact is that the solution I thought took me only few hours between the moment that I imagined, collected some ideas on the Web and implemented it.
