The Completely Fair Scheduler was merged for the 2.6.23 kernel. One CFS feature which did not get in, though, was the group scheduling facility. Group scheduling makes the CFS fairness algorithm operate in a hierarchical fashion: processes are divided into groups, and, within each group, processes are scheduled fairly against one another. At the higher level, each group as a whole is given a fair share of the processor. The grouping of processes is done in user space in a highly flexible manner; the control groups (formerly 'process containers') mechanism allows a management daemon to classify processes according to almost any policy.
To view parent comment, click here.
To read all comments associated with this story, please click here.
Member since:2005-07-24
Yes, I've noticed that when it comes to SMP related issues some FreeBSD fans like to speak of 7.0 as if it were already a stable release... and yes, compare their unreleased, bleeding edge to Linux's stable releases. That should probably not be surprising since, as the document you linked to which was written by a FreeBSD dev shows, all currently released FreeBSD versions suck pretty badly in this area. That being the case, I find it a bit amusing that they then turn around and accuse the Linux camp, which currently blows FreeBSD away on SMP performance if one compares officially released stable versions, of caring about hype more than solid engineering.
It's true that the Linux camp has done a much better job developing "mind-share", which I believe is what these people are mistaking for "hype".
But that mind-share is what makes the difference between a platform being usable as the core of my customer's infrastructures, and not. It's not the 90% of stuff that they need that is supported that matters. It's the 10% that isn't.
It's challenging enough making Linux do all the things they need, including heavy duty business accounting and shop floor control. FreeBSD is just not an option. And the difference comes down to the level of mind-share that Linux vs the BSDs have in the industry.
I've nothing against the BSDs. I'm fine with permissive licensing. And I was a Unix advocate for 8 years before I had even *heard* of Linux. But reality is reality. And I have to use what *works* for my clients. BSD could greatly benefit from some marketing savvy.
Member since:
2007-07-11
> 1. some heavy bugs in Linux, discovered thanks to
> these benchmarks
Yes, that's true.
> 2. prober configuration from the beginning with the
> help of some Linux developers
Half true. In his first benchmark Jeff was using and older MySQL version on Linux and a newer one on FreeBSD. He also wasn't using the latest development version of Linux, only the stable releases.
> 3. even today CFS is sometimes inferior to the new
> FreeBSD scheduler
That true and I didn't deny that. I only said that the latest version of CFS got some improvements.
> 4. just a note: NetBSD current beats Linux too, it's > no miracle just proper software engineering
Link please? I read @tech-kern, but they where using Linux 2.6.21 and an older glibc version (which had the malloc bug).
> Thanks god the members of LKML aren't such zealots
Well, everything I said was that the latest version of CFS has some improvements (which is true) and that FreeBSD 6.2 and 5.5 don't scale at all (also true). So who is the zealot? ;D