In the past Linux has been lambasted for being too server-centric with many new features and innovations focused on the enterprise rather than on the desktop. One of the common complaints here is how the default Linux kernel is tuned for throughput (something servers love) rather than latency (something desktop users love) – and they are two sides of the same coin with one coming at the expense of the other. Latency is important for desktops because it provides a more responsive desktop environment for the user – moving windows around scrolling a web page for example – especially while under load.
Which is why the small patch contributed by Mike Galbraith is so important as it promises to cut desktop latency by a factor of ten. The official explanation of how the patch works is loaded with developer jargon but the skinny seems to be that it takes advantage of CPU task groups and group scheduling to improve desktop interactivity on the fly while under load. Granted your system isn’t often likely to be under heavy load unless you do video encoding or software development but according to Linus Torvalds he even found web pages loading faster so it may have benefits for general system usage.
Scheduling is a vast and complex science that poses issues for Linux and Windows alike so for such a small patch to make such a big difference it’s no wonder Linus is happy with the result. The patch is included in the latest 2.6.38 kernel which likely won’t make it in time to be to be included in the next release of Ubuntu (Ubuntu 11.04 codenamed Natty Narwhal) due at the end of April. However Ubuntu developers often patch the Linux kernel with extra driver support and features so we may see this patch backported to the 2.6.37 kernel Natty is based on.