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Debating the Linux Process Scheduler
An anonymous reader writes "The Linux 2.6.23 kernel is expected around the end of the month, and will be the first to include Ingo Molnar's much debated rewrite of the process scheduler called the Completely Fair Scheduler. In another Linux kernel mailing list thread one more developer is complaining about Molnar and his new code. However, according to KernelTrap a number of other Linux developers have stood up to defend Molnar and call into question the motives of the complaints. It will be interesting to see how the new processor really performs when the 2.6.23 kernel is released."
Average? Probably nothing. But for devs/admins that are worried about certain processes taking more time than others, it -should- be more fair and keep things running smoother.
It's possible for programs right now to exploit how the current schedule dishes out time. As far as I know, they currently only do so out of ignorance, rather than malice. The new scheduler just corrects the problem.
It's not something a user can really see unless they know exactly what they are looking for, and unless a dev/admin has a program that's behaving unfairly, it's not really going to matter to them, either.
There is another invisible effect as well... Kolivas apparently publicly announced his decision to stop working on the kernel, which would include the current scheduler. That means finding another maintainer for his code, should any problems surface. If you've got 2 pieces of code that test the same in speed (as they do according to some), and 1 has a dev that's willing to keep working on it, and the other doesn't... Which would you pick?
The new code also has the added advantage of being a really really neat idea, which encourages people to work on it as well.
"If you make people think they're thinking, they'll love you; But if you really make them think, they'll hate you." - DM
There was the 2.4 schuduler, the old O(1) 2.6 scheduler and now the new 2.6 CFS scheduler...
This doenst seem to me to be ripped every 6 months, unless the 2.6 tree is just about 6 months older...
Kolivas apparently publicly announced his decision to stop working on the kernel, which would include the current scheduler. That means finding another maintainer for his code, should any problems surface. If you've got 2 pieces of code that test the same in speed (as they do according to some), and 1 has a dev that's willing to keep working on it, and the other doesn't... Which would you pick?
Wow, not even a full year has past and we're already getting revisionist historians trying to change the situation.
Kolivas quit because of the scheduler debacle, because nobody would listen to Kolivas but were apt to follow Linus and his cronie Ingo around when they drum up more-or-less the exact same thing. Instead of critically listening to Kolivas' points, Linus and Ingo attacked Kolivas' merits. Under that kind of personal attack, I couldn't say I wouldn't have quit just to shut them up. Not all of us are stubborn mules and jackasses.
"Victory means exit strategy, and it's important for the President to explain to us what the exit strategy is." G.W.Bush
What goes around comes around.
Revisionist history is working both ways I see. Whenever Linux or another kernel developer would bring up a point of failure in Kolvias's scheduler instead of Fixing the problem Kolvias would lash out and say it wasn't broken.
CFS won not because it was a better scheduler at the time, but because Inglo worked with the developers to make it better, instead of fighting everyone who questioned anything about it. FOSS projects are about helping everyone, and listening to new Ideas. Something Kolvias was having a hard time doing.
That is at least how i read the whole debate.
i thought once I was found, but it was only a dream.
You are right. It would be easy. In fact, someone wrote a patch for it called plugsched. It was not accepted into the kernel due to the fact that it would supposedly discourage the idea of simply making a scheduler which worked well for everyone.
Centralization breaks the internet.