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New Scheduler Available for FreeBSD
flynn_nrg writes "Luigi Rizzo, one of the FreeBSD developers, has just finished the code for a new scheduler. From the announcement: '...as promised, a first version of the Proportional Share scheduler that we developed is available here. These are for a recent -STABLE (i think any version from 4.4 should work; the only 3 files modified are kern_synch.c, kern_switch.c and
proc.h, plus a one-line change to kern_exit.c).
I have tested it a little bit on a diskless system, and it seems to survive running a full X session with the usual set of xterm,
netscape etc. while i do a "renice" of the processes and even switch back and forth between schedulers. But do not trust this yet for a
production system!'
Read the full post here."
what the hell happenned to developing SMP and UP capable schedulers ? or does BSD expect to run well on only UP systems ?
Why does this get on the main page, and why does the new Core Team does not?
:)
Either way, FreeBSD does fit the new trend now... more VM's means more freedom
Anybody have any idea when/if Apple will integrate improvements from this scheduler in to Darwin/OSX?
a 0(1) scheduler's overhead will not significantly increase.
The term you are looking for is probably O(n), but definatly not O(1). O(1) will not increase at all, no matter how much data is put in. O(n) will increase linearly.
Lawrence Lessig is my personal hero.
"With FreeBSD, for years, admins have been able to set certain files as "append only" (so even root can only add to, not remove from, log files) and "immutable" (so even root cannot modify or delete the file) and has been able to set firewall rules to the same (immutable) so that creative crackers can't add their personal favorites if they root the system."
Linux can do that too. That is, if you use ext2 or ext3. See chattr(1), options a (append only) and s (secure deletion).
Right now I've got four systems running Linux (RH-7.3 and 7.2) and one system running FreeBSD 4.6. At times in the past I've run OpenBSD and NetBSD as well.
I can tell you firsthand that in terms of system stability that Linux and FreeBSD are comparable if not indistinguishable. FreeBSD does seem to be more efficient however. The pentium 200 that I have FreeBSD on loads up KDE 3.0 noticably faster than Redhat 7.2 did, and once loaded it is more responsive. On older hardware FreeBSD definitely seems to have an advantage. I consider FreeBSD to be a very fast and well designed operating system. I keep trying to find places where using it instead of Linux would be an advantage.
Not everything about it is all that rosey however. The features and abilities that Linux provides but FreeBSD lacks such as SMP, kernel pre-emption, fast journaling filesystems, certain commerical software packages, 3D acclerated X servers, and generally better device support, make actually using FreeBSD as anything but an interesting toy kind of difficult to justify in many situations.
I worry about FreeBSD. I'd love to see it grow and progress not as a competitor to Linux, but as something of a companion to it. So many people just don't seem to realize that open source isn't about operating systems alone. What Linux and FreeBSD do is provide a foundation, they aren't the whole house. Both provide a powerful and stable platform for running the actual programs that people want to use in the first place. The future of open source development is going to be 90% apps and userland and 10% OS. To have religious and political wars over the OS portion is immature and counterproductive. Linux and FreeBSD aren't genuine competitors from an economic standpoint because it is the applications that both run that make either compelling in the first place.
I want BOTH Linux and FreeBSD to do well, to grow and expand and be the best operating systems anyone has ever seen. I detest the infantile immaturity of those who seek to create division and conflict between FreeBSD and Linux that simply shouldn't be there. I've gotten flames from FreeBSD "advocates" in particular filled with such hatred and obvious zealousness that you'd think they were Mac freaks, all because I described FreeBSD in terms that weren't favorable enough for their religious views. The Linux crowd is full of just as many jackasses, if not more.
Computer enthusiasts are known for generally having high IQ's. Unfortunately our reputation for having low EQ's is equally well earned. There are far too many borderline autistics and asperger's sufferers among us with severely retarded social skills. That is really the only explanation I can come up with when grown men with extensive vocabularies use them to throw a fit on par with that of an eight year old.
Anyway I'm drifting way off from what I wanted to write about. The point that I really want to make is that BOTH Linux and FreeBSD are absolutely fabulous operating systems (save the linux is just a kernel messages for church). The goals and vision behind each are so similar that any ill will between them is manufactured by immature, short sighted assholes. Microsoft is the enemy, not those who prefer another free Unix derivative that runs Mozilla, gnome, kde, etc just as well if not better than what someone else is using.
Lee
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