Preemptible Kernel Patch Accepted

An Anonymous Coward writes: "The preemptible Linux kernel patch that was originally introduced by MontaVista Software and more recently championed by Robert Love has been merged by Linus Torvalds into the main linux development-kernel tree, beginning version v2.5.4-pre6. This adds a far greater degree of real-time responsiveness to the standard Linux kernel, by reducing interrupt latencies while kernel functions are executing. The story at LinuxDevices.com includes comments by Robert Love, and there is also a recent interview with Robert Love about the preemptable kernel here and a whitepaper about the technology by MontaVista here."

Comments

Can you say "Re-inventing the wheel?"

[Mr Z]

Writing pixels directly to a frame-buffer is slow. You lose all of the acceleration features of your video card. Keeping as much of the protocol at a high level as possible is good. The only things that benefit from direct frame-buffer access are programs that do all their own rendering. (Think video decoders.)

Still, if you think about it, the basic gist of your idea is to get rid of the network channel from the communication protocol, and instead have the app talk directly to the X server, say, in shared memory. If so, then how does your idea compare to MITSHM and Shared-Memory Transport? Or the Direct Rendering Interface for that matter? And for 2-D stuff, let's not forget the Direct Graphics Architecture extension. Nothing stops GTK, Qt and friends from using any one of these technologies if they'd improve performance and latency.

--Joe