That is nice, but I'd rather see how this would be properly implemented in userspace. Pottering was eager to prove the performance increase could be applied to userspace, not how he would integrate this approach with current Linux desktops.
Also, as Linus noted, it would be nice for users to just perform a standard system update and all of the sudden have a more responsive desktop on reboot. If it can be done in userspace, distros should flesh out the userspace code and disable the kernel feature. Once it is reasonably handled in userspace across Linux distributions it can be removed from the kernel.
People with the aptitude to become community or project leaders often like a good debate (OK, sometimes it seems like an argument), and will often provoke it, if only to see how well the point can be defended. When the chips are down though, rational decisions based on facts is what wins.
I may not be as gruff as some of the more infamous names around, but I will often argue a point, as well as play devil's advocate, just to see how the debate plays out. I learn a lot that way, whether I'm correct or not.
[Edit] Re:Linus I agree that Linus' reply was a rude, and perhaps I've been desensitized to this over time, and let it slide too often. My comment however, was meant for the more general case to which I replied.
Calling someone's theory bullshit is rude and offensive. Telling someone they are full of shit is also. Abrupt and to the point as a general class of communication further is often rude. Making or attempting to make people feel worse than you need to to get your point across efficiently is offensive.
In this case, for example, Linus could have simply said, "That's a nice theory. If you can prove it, we'll consider it." That's more to-the-point, communicates the entirety of what Linus managed to in his email, and also is not rude.
There is also context and a dynamic that outsiders may not always aware of. A colleague of mine could say "you're full of shit - come back with something that works", and I would be more likely to take that as a challenge than an insult. Similarly, within the LKML, this response is somewhat expected, and you better have your defense ready for the ensuing battle.
"And you're just full of bullshit."
You can be "abrupt and to the point" without personal attacks. Linus personally attacked him, without knowing all the facts.
More to the point, Linus is known for that kind of comment. A lot of the time his point is as important as it is off-putting (see the git vs. C++ rant.)
I was wondering when the freedesktop dudes were going to make a "come back". Linus, in fact, does not oppose the user level approach [1]. I too, however, share his disgust for user level code to interact with every process and group, it's just awful. The kernel seems like a good place to implement an interface for this, that user space can use effectively and without imposing extra complexity on the kernel.
It seemed like the CPU graph seemed to show higher cpu utilization line-trace for the core that was running the benchmarking Chrome process.
That's my layman observation after the patch.
That implies "this should have been done from the beginning, but the developers were lazy / incompetent"
Also, it is better to have 500 lines of well-commented code with informative variable names, than just the right 200 lines. Software development should not be reserved for voodoo witch doctors who know just the right mysterious incantation to produce the desired effect.
Encouraging people to have the mentality "do it in < N lines or don't try" seems silly.