Interview with Matthew Dillon of DragonFly BSD

JigSaw writes "Well-known FreeBSD/DragonFly/Linux/Amiga system hacker Matthew Dillon discusses a number of interesting points regarding where the BSDs are going, the status and goals of his latest project DragonFly BSD, the status of his innovative Backplane distributed database, his exciting plans to develop DragonFly into a transparently cluster-capable system implementing native SSI (Single System Image) which is something that no other operating system can do today, and more."

Comments

I guess that'll show em.

[AltGrendel]

BSD isn't dead.

Re:I guess that'll show em.

[zaunuz]

BSD is faaaaar from dead. I'd say that those who claim BSD to be dead dont know what they are talking about. Ive been using FreeBSD as desktop and server OS for 3 years, while ive never really gotten down and dirty with linux, and i cant say i regret my choice of OS. BSD still lives, and (atleast for me) allways will.

Re:I guess that'll show em.

[thestarz]

There are now four BSDs, yet there is only one Linux. Is there something about BSD that makes it fork-prone, or something about Linux that makes it fork-resistant?

I'm not critisizing either one. I'm just curious, any thoughts?

Re:I guess that'll show em.

[ScrewMaster]

This is Slashdot, where any sufficiently advanced opinion is indistinguishable from fact.

Re:I guess that'll show em.

[Anonymous Coward]

That's funny. One thing that drives me crazy with linux is how it is always changing.

Redhat9 binaries won't work with redhat7 and debian does things their own way. While mandrake and gentoo do it this way. Then suse jumps in and blah blah blah.

Sure they all use the same kernel but usually it is never the same kernel.

Re:I guess that'll show em.

[Rick the Red]

I think of the various Linux distros as "forks" of whatever Linus himself runs. There are literally dozens of Linux forks. Too bad Linus doesn't release a distro, so we'd know what Linux is supposed to look like. If you sit down at a Linux system you have no idea what you're going to find. From a Systems Administration standpoint alone that makes *BSD a better choice for corporations with a large number of hosts, but Linux gets all the press.

Re:I guess that'll show em.

[SillyNickName4me]

Hmm.. yeah, since a recent update I can no longer run a.out binaries from the 2.x era... but for as far as external packages and ports are concerned, thats about the first case where you can't get software for older releases to work with a current version using one of the compatxx packages.

That said, some tools (esp those using kmem) should be kept in sync with the kernel, and when at it, why not just build a new userland, its easier then figuring out what you have to update.

The concurrently developing BSD variatiens allow trying out a variety of low level solutions to problems while sharing a lot of their experiences.

Such diversity doesn't really exist in Linux despite its zillion distributions (which provide a lot of variation in user experience tho)

Re:I guess that'll show em.

[Anonymous Coward]

If you sit down at a Linux system you have no idea what you're going to find. From a Systems Administration standpoint alone that makes *BSD a better choice for corporations with a large number of hosts, but Linux gets all the press.

Seeing as just Red Hat or Debian already have more market share than any BSD, by your own logic, you are wrong.

Re:I guess that'll show em.

[Mizery De Aria]

Obligatory BSD == "BSD is So Dead" || BSD == "BSD is Still Dead";

Re:I guess that'll show em.

[Anonymous Coward]

Is there something about BSD that makes it fork-prone, or something about Linux that makes it fork-resistant?

A BSD is an entity, comprising user-space apps, plus a kerel - think of the *BSDs as the equivalent of Linux distributions.. the difference is that with Linux, you have different user-space apps, with a common kernel, whereas the *BSDs are the other way around (the support apps are the same, but the kernel is different - yes, I know there are differences, but this is the basic gist.)

In that light, Linux would actually have more forks than *BSDs, as there are more than four Linux distros.

Re:I guess that'll show em.

[UID500]

Um, linux is a kernel, not a distro. the linux kernel is what "linux is supposed to look like" to linus.

Re:I guess that'll show em.

[Anonymovs Coward]

Um, linux is a kernel, not a distro.

Which is unfortunate in many ways. For example, Matt has introduced variant symlinks into DragonFly, and has major plans involving vfs namespaces etc which will really solve a lot of problems in package management, like allowing two different conflicting versions of a package to exist at the same time. He can do all this because he's looking at the whole picture, and so are the others: the entire source tree for the base system is there on my machine, in one nicely-arranged subdirectory. I don't foresee major changes happening in the linux kernel driven by distributors. To this day, breakages with binary-incompatible glibc etc are constant annoyances with linux unless you choose a stable distributed version from a branded linux distro and stick to it. the linux kernel is what "linux is supposed to look like" to linus.

What is "the linux kernel"? There's a Red Hat kernel, a Mandrake kernel, a SuSE kernel, and you can't really drop a generic Linus kernel into any of the commercial distros and expect it to work properly. (Debian and Gentoo are better.)

I'm not dissing linux, it's better than the mainstream alternatives and has far better hardware support and graphical system administration tools than the BSDs. In fact after 2 years with FreeBSD I myself had switched to Linux on my new machine because of hardware issues (I've now mostly switched to DragonFly and the hardware issues are mostly gone). And I use Linux at work and have no desire to change that. But there are reasons why a lot of technically aware people find the BSDs nicer systems to play with.

Re:I guess that'll show em.

[4b696e67]

Too bad Linus doesn't release a distro, so we'd know what Linux is supposed to look like.

If I'm not mistaken Linus has said he won't endorse or release a distro for that reason alone. Friendly competition between the distros is a good thing. It sparks invention and true innovation. Even the various *BSDs help each other out.

If you sit down at a Linux system you have no idea what you're going to find.

I disagree there. Most *nixes are fairly similar. You have a /dev directory. You have an init process. You have standard utilities such as ls, cp, grep, sed, awk, etc. I have used AIX, Solaris, FreeBSD, and Linux and they do have their differences, but they are more alike than different.

From a Systems Administration standpoint alone that makes *BSD a better choice for corporations with a large number of hosts, but Linux gets all the press.

I disagree there as well. I feel that from an administration standpoint with a large number of hosts it wouldn't matter if you were using RedHat, Gentoo, FreeBSD, OpenBSD, or any other *nix for that matter as long as the machines you were running were using the same distro. No, you wouldn't want 10 RedHat boxes, 20 OpenBSD boxes, 35 Gentoo boxes, and 15 AIX boxes. On the other hand, if you had 80 Gentoo boxes that were all kept up to date you wouldn't be any worse off than if you had 80 FreeBSD boxes (generally speaking, I know each OS has its strengths and weaknesses).

IMO the best OS to administer is the OS you know. You could have the best/most secure OS ever, but you would still get owned if you didn't know how to administer it. Hell, even the "security hole haven" Windows can be made more or less secure by a good admin.

Re:I guess that'll show em.

[anthonyrcalgary]

As I'm sure we're all aware, market share is not necessarily indicitive of quality or suitability for a given purpose. Just think about what that would say about Windows if it were true.

Re:I guess that'll show em.

[Anonymous Coward]

No it isn't unfortunate at all. Linux really has very few problems with userspace backward compatibility. What did you have in mind?

And BSDs are more likely to introduce binary incompatibilities because they are the sole managers of the kernel, libc and other major pieces.

Re:I guess that'll show em.

[Anonymovs Coward]

Linux really has very few problems with userspace backward compatibility. What did you have in mind?

Merely my brief experience with Gentoo, when they first upgraded glibc (from 2.2 to 2.3 iirc) and broke half the packages, then downgraded it again and broke everything else. This is really a pet peeve: aren't minor versions supposed to be compatible? And a zillion similar but smaller-scale annoyances, well expressed by Bill Paul many years ago and the years haven't eased the pain all that much.

And BSDs are more likely to introduce binary incompatibilities

Clearly you haven't used the BSDs. You may have library incompatibilities between major versions, but just install the earlier "compat libraries" and you're set. I upgraded from FreeBSD 4 to FreeBSD 5 -- a huge upgrade, over 2 years in the making -- and all my software just worked, even complex stuff like KDE and Mozilla that had been compiled under 4.x.

Re:I guess that'll show em.

[Anonymous Coward]

you forget that Linux is simply a kernel, and everybody knows what it looks like. the distributinos are simply amalgamations of free and non-free tools that have nothing to do directly with Linus. if he put out a distribution of Linux, it would merely be the Linus Distribution using the Linux Kernel. you can switch around the kernels and it's no longer a Linux distribution, it's a BSD distribution, or a HURD distribution, or whatever you wish to call it. this is why Stallman gets so anal over calling it the GNU/Linux system - not because it's GNU-based necessarily, but because it's a "system" with both GNU tools and a Linux kernel.

bottom line is that Linux distributions are about personal preference. if you wanna know the ideal Linus system, just ask him what he's using now and that's it.

Re:I guess that'll show em.

[Anonymous Coward]

No offence, but Bill Paul didn't know what he was talking about. If you don't know how to manage upgrading the kernel outside the distribution framework (which clearly he couldn't manage), then just stick to a distribution. It is no harder to break old BSD kernel utilities or libc by installing a new kernel.

You may have library incompatibilities between major versions, but just install the earlier "compat libraries" and you're set.

Yeah, this is exactly what good Linux distros do. Nothing new here.

Re:I guess that'll show em.

[Rick the Red]

I feel that from an administration standpoint with a large number of hosts it wouldn't matter if you were using RedHat, Gentoo, FreeBSD, OpenBSD, or any other *nix for that matter as long as the machines you were running were using the same distro.

You haven't actually been an admin at a company with a large number of machines, have you? I worked for a large aerospace company and our Management (he wasn't even a PHB) wanted to know why we had an average of one admin for 20 machines when HP said one admin should be able to handle 200. Then HP explained that those 200 machines were absolutely identical -- same exact hardware, same exact OS patch level, and same exact applications. In the Real World, we had no two machines alike and thus needed the 1/20 ratio. And this was all the same brand of hardware and OS! Each department was different, which basically made vacation and illness backups a matter of "pray they don't call you." The admins who had the easiest time of it were those who worked on BSD boxes; the VR4 boxes were all over the map; even the users understood that if their admin was away, they were better off not bothering the backup on call for any more than password resets because they'd as likely break something else as fix your problem.

Granted, if you ran an all RedHat shop or an all Mandrake shop things would be easier than simply an all Linux shop, but the same would be true for an all OpenBSD shop vs an all FreeBSD or NetBSD shop. But if each department is free to buy what they want I'd rather find who-knows-which-BSD on the box than who-knows-which-Linux.

Re:I guess that'll show em.

[Anonymous Coward]

Hmm.. yeah, since a recent update I can no longer run a.out binaries from the 2.x era... but for as far as external packages and ports are concerned, thats about the first case where you can't get software for older releases to work with a current version using one of the compatxx packages.

Yeah, and on Linux here I can run libc5 a.out binaries no problem. The point wasn't that BSD has a binary compatibility problem, just that Linux doesn't have one either.

The concurrently developing BSD variatiens allow trying out a variety of low level solutions to problems while sharing a lot of their experiences.

Such diversity doesn't really exist in Linux despite its zillion distributions (which provide a lot of variation in user experience tho)

Are you talking about BSDs having different kernels? You probably didn't realise there are literally thousands of different kernel patches and trees being maintained by different parties with different directions.

Re:I guess that'll show em.

[Anonymous Coward]

Actually it is not uncommon at all to have a large number of identical systems. Think of a computer lab at any university, school, or company. Any sort of server farm or cluster. Companies are even heading in this direction for employees' workstations.

Re:I guess that'll show em.

[Tony-A]

A sufficiently advanced opinion is a fact.
Or soon will be ;-)

Re:I guess that'll show em.

[ScrewMaster]

At which point it becomes hindsight, and no longer quite so advanced.

Re:I guess that'll show em.

[yanestra]

Merely my brief experience with Gentoo, when they first upgraded glibc (from 2.2 to 2.3 iirc) and broke half the packages, then downgraded it again and broke everything else. This is really a pet peeve: aren't minor versions supposed to be compatible?

There's a big difference between binary executable and logical compatibility. You have compiled several files with newer libraries and then downgraded. You expected that the newly compiled programs to run with old libraries - which they in fact do, as long as there has no special feature of the newer libraries been used - inherently.

If you are unhappy with your executables be broken, simply keep a copy of the older libraries. (With Gentoo, simply delete the old package file in /var/db/pkg before updating.)

Re:I guess that'll show em.

[Anonymous Coward]

Um, linux is a kernel, not a distro.

Tell ya what. When you are successful in getting people to stop using the word "Linux" as a catch-all for 'any $0 cost open source software', then I'll back your definition.

Re:I guess that'll show em.

[SillyNickName4me]

> Yeah, and on Linux here I can run libc5 a.out binaries no problem. The point wasn't that BSD has a binary compatibility problem, just that Linux doesn't have one either.

I am quite aware that that is possible, I have maintained a Linux distribution for abotu 1 1/2 years for a small company, and we had no problem with binary compatability.

That said, it is a rather common experience for a Linux end-user to run into a package meant for an older version of their distribution, and having to actually know what they are doing to get it to work, whereas this is not the case on BSD.

Besides, my comment was a reply to a claim that BSD did NOT offer such backward compatibility, read the parent maybe? :)

> Are you talking about BSDs having different kernels? You probably didn't realise there are literally thousands of different kernel patches and trees being maintained by different parties with different directions.

I am aware of that, and I have used several of those. With all respect for their maintainers, few have the level of consistency and userbase to be an option for me for a production environment, there are 4 BSD variations (on kernel level) that do offer substantially different solutions and hardware compatability while all being quite an option for a production environment.

Re:I guess that'll show em.

[SillyNickName4me]

Oh, and I forgot.. you can still enable a.out compatability, its just no longer there by default it seems. All it takes is compiling a new kernel.

Re:I guess that'll show em.

[Anonymous Coward]

" In the Real World, we had no two machines alike and thus needed the 1/20 ratio. And this was all the same brand of hardware and OS!"

You guys are lucky! We have 5 admins to handle over 300 machines that vary from sparcstation 5's, to V880's, to HP ProLiants, to high-end PA-RISC hardware.

You better believe we pray that we don't get called when one of the "insert product here" experts goes on vacation. And when I go on vacation, I pray nobody manages to get ahold of me !

Being seriously understaffed sucks, although it's good for job security... Until the company sinks itself.

Re:I guess that'll show em.

[jovlinger]

confusion.

Isn't the point of a single system to have exactly identical machines? You either mount / over NFS or have an image you blast onto the machines regularly. You absolutely mount /home over NFS, and use local disk only for transient, unbacked up data --- like builds, scratch, swap.

I think HP was right on the money; allowing your infrastructure to heterogenize is a bad thing.

Note that you can still have dept-local configurations, as long as they are centrally managed images. The idea is that if any machine breaks, you can take it away and replace it without any loss (modulo the transient files) to the user.

Of course, I've never managed more than 3 machines, so I'm probably missing something: what?

Re:I guess that'll show em.

[Anonymous Coward]

As I'm sure we're all aware, market share is not necessarily indicitive of quality or suitability for a given purpose. Just think about what that would say about Windows if it were true.

Certainly true. But you miss the point. The parent claimed that BSD was better for system administrators because they provide a consistent interface. But when you stick to a single Linux distribution, you get the same advantage - and you'd still have a larger pool of experienced people to draw from.

Re:I guess that'll show em.

[anthonyrcalgary]

It's not practical to have 100% identical machines most of the time. After a while the original replacement hardware starts getting hard to find, but a lot of the time there's no reason to replace the machine. And if you did replace the machine, everything wouldn't be identical anymore...

If you're in a company with any significant number of computers, you have literally tons of spare parts lying around. All the machines will drift as they're maintained, and get customized. Someone might need more memory, someone else might need dual monitors, etc.

Re:I guess that'll show em.

[mrogers]

linux is a kernel, not a distro. the linux kernel is what "linux is supposed to look like" to linus.

Damn right. Real hackers don't need a GUI, a shell, file utilities or even a C library. Real hackers just need a system call interface. malloc() is for end users - real hackers use brk().

Of course if it wasn't for all those pesky users cluttering up our systems we could write directly to the hardware. Damn protected memory nanny state.

Re:I guess that'll show em.

[tigga]

Hmm.. yeah, since a recent update I can no longer run a.out binaries from the 2.x era...

What's the problem?

If you want to run a.out binaries you need to run:

kldload aout

If problem in 2.x binaries - install compatibility libraries.

Re:I guess that'll show em.

[Anonymous Coward]

Yeah, it just doesn't do that by default.

Re:I guess that'll show em.

[Anonymous Coward]

Even the various *BSDs help each other out.

By taking turns with the shovel?

Re:I guess that'll show em.

[Anonymous Coward]

Maybe he's talking about pallbearers.

Re:I guess that'll show em.

[rweir]

Merely my brief experience with Gentoo, when they first upgraded glibc (from 2.2 to 2.3 iirc) and broke half the packages.

This is a gentoo problem, not a Linux one; I've been through two glibc changes on Debian without breaking anything.

Re:I guess that'll show em.

[Anonymous Coward]

No it's not. The packages broke 'cos glibc breaks binary compatibility with most MINOR releases.

You didn't get the problem 'cos Debian handled it reinstalling the whole lot (you've gotta love apt-get) as required.

Gentoo didn't upgrade all the packages -> he got broken packages all over the place.

This is something that has pissed me off for quite a while, glibc updates break compatibility far too often.

A happy Debian user

Re:I guess that'll show em.

[SillyNickName4me]

While BSD offers different implementations on kernel level suited for different uses while offering a pretty consistent userland on top of that.

Re:I guess that'll show em.

[walt-sjc]

you can't really drop a generic Linus kernel into any of the commercial distros and expect it to work properly

Huh???? Generic kernels work just fine. You just need to configure them with the correct options. All RH and others do is take a generic kernel and add some additional patches such as IPSec, updated drivers, etc., but none of those are needed for day to day usage for the most part. These are NOT forks of the linux kernel.

In fact, it's a very good idea to maintain your own kernel with just the options you need. Why do you want the bloat of a kernel that supports 800 different network cards, Ham Radio protocols, etc???

Note that I'm not 100% happy with the way you have to deal with the Linux kernel. Adding drivers is a pain. I hate having to download and patch to get working SATA support for example, and alsa in 2.4 sucks to deal with (resolved in 2.6.) It was a Pain in the ass to get Debian Sid up on my new system.

The thing that bugs me with various distros has nothing to do with the kernel - it's things like system administration - where is the IP address configured? Is it inetd or xinetd? Is apache's conf in /etc/httpd or /etc/apache? Oh hell, theve gone and taken a nice simple /etc/exim/exim4.conf and split it into a huge directory tree. Once you are up to speed on one distro, it takes a bit to figure out the ideosyncracies of another.

BSD has it's own issues, but I have confidence in MD. I've used his stuff way back in the Amiga days - he's a very good coder. I'm going to be taking a Very hard look at DragonFly.

Re:I guess that'll show em.

[Anonymous Coward]

The key difference is that Linus Torvalds owns the name 'Linux'. If you try to create a fork of Linux, he can just refuse to grant you the right to call it Linux, so unless Linus decides to fork Linux, there can only every be one.

BSD is more generic, since it refers to the OS developed by the now-defunct CSRG at UC Berkeley. Anyone who wants to create a FooBSD fork of an open-source BSD-derived OS can do so, without trademark fears.

The other thing is that in the early 1980s, the original 'father' of BSD (Bill Joy) decided with some colleagues to found Sun, and since that time there hasn't really been a single towering figure in the BSD world (there have been several important figures, but none nearly as central to BSD as Linus Torvalds is to Linux).

Re:I guess that'll show em.

[Anonymous Coward]

I think this is an issue of user-level compatibility (e.g. the file system layout, binaries included by default, etc.), not ABI compatibility.

The *BSDs provide a fairly consistent userland, which is also still somewhat consistent with old BSD systems like SunOS (1-4.x). That's what I like most about them (although I was a SunOS 4.x user before I was a Linux or *BSD user, so that has coloured my views).

The Linux distributions I've used have varied so much that switching between two of them has felt much more like using different OSes than, for example, switching between NetBSD and FreeBSD. The randomness of Linux distributions is what has motivated the the creation of things like UnitedLinux.

Another thing I like about the multi-kernel BSD world is that the different branches can try doing things differently. If one way of doing things proves dramatically better in the long run, the others can adopt it. On the other hand, Linux has the advantage of binary compatibility of kernel modules across distributions. Overall, I'm not sure which I prefer in this respect (one kernel to rule them all, or multiple kernels to allow for different ideas).

Re:I guess that'll show em.

[Dick Faze]

There is one Linux like the guy busting Rodney Dangerfield's balls in "Back to School" only had "One Question" on his final exam. "One Question.....in one hundred and twenty-eight parts".

Re:I guess that'll show em.

[mi]

You absolutely mount /home over NFS, and use local disk only for transient, unbacked up data --- like builds, scratch, swap.

Actually, the setup, I'm trying to develop, keeps everyone's home directory on their own desktop -- the machine, they are most likely to use most of the time. It is automounted elsewhere, when needed with automounter's map available through NIS. This gives the speed of local disk, the features of file system, that may not work through NFS, and reduces network traffic.

On the downside, you have to back things up from many machines, which is fine, IMHO...

And yes, I'm in favor of netbooting and NFS mounted / and others -- the aproach made very easy by FreeBSD -- thanks in no small part to Matt Dillon before he started his own project.

Trying to make a net-bootable RedHat left me shaken and scarred for life...

Different threading model

[Mr. Darl McBride]

It looks like the gist of the threading model for Dragonfly is that threads all stay on one processor. I assume this is for user processes only, and that this isn't pervasive through the kernel?

Re:Different threading model

[Anonymous Coward]

No BSD secrets for you, Darl!

Re:Different threading model

[Mr. Darl McBride]

It looks like the gist of the threading model for Dragonfly is that threads all stay on one processor. I assume this is for user processes only, and that this isn't pervasive through the kernel?

Nevermind, found an overview here.

Re:Different threading model

[Kaladis Nefarian]

No this is to do with kernel threads. The userland threading is the same as in FreeBSD 4.x atm, AFAIK. The idea is to keep the model simple, unlike in FreeBSD 5.x where they are having trouble keeping it all sane with their fine-grained mutex model. Have a look at the dragonfly.kernel newsgroup, in nntp.dragonflybsd.org for more details on the SMP model, Matt talks about it regularly earlier on.

Re:Different threading model

[Mr. Darl McBride]

No BSD secrets for you, Darl!

It is important that I discover what they have created so that I may license it back to them.

~Darl

Re:Different threading model

[Anonymous Coward]

So it looks like they use a concept of 'serializing tokens' to make sure individual threads don't change variables that another thread might be working on, instead of mutexes. I don't yet understand completely what advantages either system has over the other. Does anyone here know?

Re:Different threading model

[m.dillon]

Not exactly. All this means is that threads do not migrate preemptively, nor do they migrate while blocked or switched out while in kernel mode. Threads only migrate if (a) the thread itself wants to move to another cpu or (b) the thread is returning to user mode and the userland scheduler decides to migrate the thread to balance the load out (which only applies to threads associated with user processes since no other type of thread can 'return to usermode').

Kernel threads almost universally stay on the cpu they were originally assigned to. High performance threaded subsystems, such as the network stack, are replicated. That is, the network stack creates multiple threads (one per cpu) and those threads do not migrate because, obviously, they do not need to.

Generally speaking, the purpose of making thread migration explicit instead of automatic is to partition a larger data set across available cpu caches rather then cause the same data to be shared amoungst all cpu caches. The processors operate a lot more efficiently and SMP scales a lot better. Most people do not realize the horrendous cost of moving threads between cpus because the cache mastership change is invisibly handled by hardware, but the cost is still there and still very real.

-Matt

Re:Different threading model

[Anonymous Coward]

The cost of moving a thread between CPUs isn't very much. A bit more than a context switch because when you context switch you might have a bit of your old data left in cache somewhere.

A big problem is sharing cachelines between CPUs, where one or more of those CPUs writes to that cacheline. This problem is second only to lock serialisation when it comes to SMP scalability.

The Linux kernel for example may move tasks between CPUs (when the task isn't running, of course). This doesn't in any way prevent the use of per-CPU data.

Also, I notice in some places (if I remember correctly), you say things like "the scheduler can be done lockless, with just a critical section". Presumably the critical section needs to be locked, right? Otherwise it isn't a critical section.

One more thing if I may. Your "token" is semantically a type of lock, correct? Do you have spinning locks at all, or are they all blocking types?

Re:Different threading model

[Mr. Darl McBride]

At what level does this model give way to standard mutexes? You can't have four drivers for your network card on a four CPU system or four drivers driving your ATAPI bus.

Do you do anything special in the mutex code to take advantage of the four async top level threads and prevent mutex waits?

Re:Different threading model

[Mr. Darl McBride]

I should also ask -- is this thread replication model your own design, or do you know of any papers or previous implementations?

Re:Different threading model

[m.dillon]

The system core is lockless... there are no mutexes. For example, the LWKT scheduler core operates entirely without mutexes. Only critical sections are used to protect against local interrupts. A critical section is per-cpu, and really only needs to increment and decrement a per-cpu variable. As such the crit_enter()/crit_exit() code does not need to use any locked bus-cycle instructions or anything fancy at all, really.

The LWKT scheduler on any given cpu is only allowed to operate on threads owned by that cpu. If you attempt to wakeup a thread owned by a different cpu, an asynchronous IPI message is sent to the target cpu's LWKT subsystem requesting that the specified thread be woken up. It's really that simple. Same goes for cross-cpu scheduling.

IPI messages themselves are lockless and require no mutexes to operate because the cpucpu messaging uses a software crossbar (array of FIFOs) approach.

Re:Different threading model

[m.dillon]

No, the critical section code simply increments and decrements a per-cpu variable. No locking is required at all... critical sections are local to the cpu, not global to the system.

In regards to cache issues, lets say you have a quad opteron system. Each cpu has a 1MB L2 cache. If you migrate threads willy nilly you basically wind up in a situation where each of the four cpu's L2 caches contain the same data. In effect, you wind up with a system that globally has only a tad more then 1MB of L2 cache. If you partition data (such as TCP protocol data) across distinct threads, and place those threads on different cpus, then you are in effect partioning your system's memory across all four cpu caches and you wind up with a system that globally has 3-4MB of L2 cache instead of 1-2MB.

There are two costs being saved here. (1) the cost of having to go to main memory when a piece of data is not in the L1/L2 cache, which can run into the hundreds of cpu cycles, and (2) the cost of cache mastership changes for all the data associated with the thread that was migrated (repeated each time the thread migrates).

-Matt

Re:Different threading model

[m.dillon]

I don't think it's anyone's design in particular, but I tend to sit down and write things from scratch rather then copy other people's ideas. In the case of the thread replication used by the network stack, it is primarily Jeffrey Hsu's work and since he is big on reading papers I'm sure it's a combination of his own design and ideas gleaned from various published papers.

Re:Different threading model

[m.dillon]

It's an advantage in concept. The serializing token abstraction is a far easier model to program to because the semantics are totally different then mutexes. For example, when you obtain multiple mutexes you have to be very careful about lock ordering issues, and when you have one major subsystem holding a mutex call another major subsystem that might block, you have to (in FreeBSD-5) make the second subsystem aware of the first subsystem's mutexes, creating major code pollution all over the place.

The serializing tokens used by DragonFly work differently. They only guarentee serialization while the thread holding the token is actually running. Other threads holding the same token will be allowed to run when the first thread blocks or switches away synchronously, and the original thread will not get the cpu back until the tokens it is holding are available again.

This means that threads can obtain tokens in any order they wish, and that threads can hold tokens across blocking situations or calls to other subsystems without having to tell those subsystems about it. It may seem like a small thing, but the result is a huge simplification of the programming model. The tokens act almost like mini-BGL's (Big Giant Locks) but have the added advantage of protecting against interrupt threads trying to hold the same token. We are planning to expand the token idea further into a shared/exclusive model. The shared/exclusive model would have characteristics very similar to RCU.

The actual internal implementation of our token code is also quite a bit more flexible, allowing us to rip the guts out and rework it as needed for performance without changing the abstraction.

-Matt

Re:Different threading model

[cant_get_a_good_nick]

Jokes aside, that's essentially what the first AT&T lawsuit did... it sued BSD because they released source code and that lowered the value of UNIX with a (TM), when major portions that made UNIX with a (TM) useful were actually made by BSD.

For a project that gets no press

[RLiegh]

Dragonfly BSD seems to be chugging along quite nicely.

The further away they get from their 4.x FreeBSD roots, though, the more I wish they'd release an ISO. Particularly since the last ISOs for the 4 series of FreeBSD are probably going to be totally gone in a few months.

Re:For a project that gets no press

[Anonymous Coward]

The truth is that right now it looks quite like FreeBSD-4.X. The changes he's made to FreeBSD are more or less invisible to the average user right now. Watch this space though.

Re:For a project that gets no press

[Anonymovs Coward]

They do have ISOs, click the "download" link on their main page. The ISO is a liveCD, so you can boot your computer with it, like knoppix (no X or GUI stuff though). What they don't have is a friendly installer. But the /README file has detailed instructions on installing it to the hard disk, which should be easy if you have BSD experience, or if you're a brave newbie you can try it anyway.

Here we go again

[Blair16]

Queue the BSD is dead posts.
Why can't we all just get along??

Re:Here we go again

[buffer-overflowed]

Because BSD users have a mascot called "Beastie" who is a devilish little chap and they use "daemons" to accomplish things that seem like magic to normal people.

So, you see, it's obvious... BSD made a deal with the devil! And it's users weigh the same as ducks, therefor they are made of wood, and since they're made of wood, they are witches!

I mean, didn't you ever wonder why we call them "holy wars"?

Re:Here we go again

[Ashish Kulkarni]

heh, you might want to take a look at this joke. ;-)

What?!

[Anonymous Coward]

Are you saying FreeBSD is dying? This is the first I've heard of it.

Re:What?!

[RLiegh]

It's official. ftp.FreeBSD.org/pub/FreeBSD/iso confirms it. FreeBSD 4.x is dying. kreskin... usenet... falling dead last in the number of ISO's distributed on ftp.freebsd.org ....all practical purposes...stephen king is dead.

Re:What?!

[Rick the Red]

Oh, come on, moderators, be consistent! If RLiegh is funny, then Stephen King is funny; if Stephen King is offtopic, then RLiegh is offtopic.

I hope I get one of these in MetaMod.

Re:What?!

[Anonymous Coward]

If RLiegh is funny

But he isn't. King, however, is. It's not an issue of consistency, it's an issue of the moderators being completely wrong (also stupid).

Divide and conquer

[florin]

Yeah yeah forking is always sweet and this sure sounds like a lot of fun already, but what I'm really waiting for is for someone to put together a BSD-from-scratch distribution! I mean, I know I could just build one with Linux.. BUT only having a single kernel to choose means my grimy little subculture won't be as obscure as it could be. Just think how exclusive I'd be if I could pick one of the NetBSD, OpenBSD, either of the active branches of FreeBSD, and PicoBSD, Dragonfly BSD or Darwin kernels..

Re:Divide and conquer

[Anonymous Coward]

There is no need for BSD-from-scratch disto.

1: All the BSDs are entirely different operating systems, which are lumped into one category becuase of their roots.
2: Since no extra bullshit is thrown in like linux, there is less need for reworking the base.
3: BSD is not obscure in the least, it is rather alive and florishing.

BTW you forgot to mention Solaris, which has it's roots in BSD too.

Re:Divide and conquer

[Anonymous Coward]

If you REALLY feel that way (and the dripping sarcasm makes me doubt that you do), there is always GNU/HURD. It's practically BEGGING for someone to come and make the next SLS with it!

Re:Divide and conquer

[Anonymous Coward]

2: Since no extra bullshit is thrown in like linux, there is less need for reworking the base.

What bullshit do you mean, and isn't some of it providing functionality that simply doesn't exist in any BSD?

And if there's less need for reworking the base, why do they have so many separate kernel projects with one particular focus?

Re:Divide and conquer

[Anonymous Coward]

1: Becuase the kernel is not part of the base. Base includes the basic userland stuff such as the startup scripts and the like.
2: They each have different goals.

BTW your functionality claim is total bullshit. Which OS you talking about. BTW BSD is not a actual OS, which I may have pointed out earlier. If it does not exist in one, it nearly all ways exist in anothe.

Re:Divide and conquer

[Anonymous Coward]

1: Becuase the kernel is not part of the base. Base includes the basic userland stuff such as the startup scripts and the like.

Again, what bullshit are you talking about that is in 'linux' and not in BSD? Don't you think it is there because someone wanted it? And why don't you simply choose not to install it or even pick a stripped down distribution to begin with?

Apropos startup scripts, do BSD people even understand SysV-style inits? Sometimes one gets the impression it is just a step too complicated or something.

2: They each have different goals.

And methods, and quirks to learn. And they sooner or later reinvent the same things. Not necessarily an advantage.

BTW your functionality claim is total bullshit. Which OS you talking about. BTW BSD is not a actual OS, which I may have pointed out earlier. If it does not exist in one, it nearly all ways exist in anothe.

Oh well you know, just all sorts of functionality that was driven by Linux, like finely grained SMP, support for enterprise level hardware, USB, SANE, ACPI, DRI/DRM and what have you more. And let's not get started on the apps. I mean, there's a reason why all the BSDs make an effort to run Linux binaries, not the other way around.

Re:Divide and conquer

[N1KO]

Even if BSDs init scripts and other base stuff is super terrific now, it won't be in 10, 20 or 100 years. Eventually one of the OSs will make changes that are incompatible with the others.

From that interview, it sounds like DragonFly is going to have a different package management system in the future. Which means either the base is going to change, you will stop calling it bsd or you will say ports isn't a basic part of bsd

Re:Divide and conquer

[Anonymous Coward]

Interesting given that there are all ready differences between the base system of the various base systems.

Re:Divide and conquer

[Rick the Red]

GNU/HURD is begging, alright. Begging for developers, begging for users, begging to be noticed. Does anyone actually use it? Even these guys don't.

Re:Divide and conquer

[Anonymous Coward]

And if there's less need for reworking the base, why do they have so many separate kernel projects with one particular focus?

Prove it, nitwit.

Re:Divide and conquer

[Anonymovs Coward]

From that interview, it sounds like DragonFly is going to have a different package management system in the future. Which means either the base is going to change,

The BSD base isn't packaged. BSD types like having a source tree for their entire base system and being able to do "make buildworld" and "make installworld" to upgrade it. The package management system is entirely for third party applications. This is not Debian or Gentoo who have no code maintained by themselves other than installation and package management stuff. The BSDs maintain the kernel, the libc, other key libraries, and all the base utilities like ls, cp, mount, etc. And there's also a lot of "contrib" software in the base system -- some of it necessary to build the system (gcc and binutils), some of it just there out of tradition or regarded as "too useful to be moved to ports" (bind, sendmail).

Re:Divide and conquer

[Rick the Red]

Attention Moderators:

If my post was "Flamebait" then answer my question: Who actually uses GNU/HURD? The GNU guys don't even use it! That's a statement of fact, not a flame. I certainly don't expect them to use anything that's not released under the GPL, so their use of Linux is no real surprise, but given Stallman's history with the whole "Linux" vs "GNU/Linux" thing I'm assuming he'd use GNU/HURD if it was any good.

Re:Divide and conquer

[Anonymous Coward]

Oh well you know, just all sorts of functionality that was driven by Linux, like finely grained SMP, support for enterprise level hardware, USB, SANE, ACPI, DRI/DRM and what have you more. And let's not get started on the apps. I mean, there's a reason why all the BSDs make an effort to run Linux binaries, not the other way around.

hold on cowboy...
linux drove usb support? check your history...

linux has better support for smp? right... 'cos the linux smp support isn't a rip of free-bsd's first smp incarnation, and free's 'new' smp code is some hack up by a big school kid is it?

linux has better support for enterprise hardware? shall we start with... i dunno... scsi support... get your history book out and do some experimenting with old linux v's old *bsd installs - try backing up a raid and restoring, then come back and tell me how good scsi isn't fundamental enterprise computing...

next you'll tell me that open's code auditing and goal of bug-free secure code is inferior to linux's free for all crap-code fest

excuse my rant, i'd don't mean to bag linux - every OS has its place - even windows.

but man... linux zealots and their damn superiority complex, re-writing history... i even heard someone try to explain the sco crap the other day... he actually said that 'unix is a brand of linux'

Re:Divide and conquer

[allenw]

BTW you forgot to mention Solaris, which has it's roots in BSD too.

SunOS 1-4 were primarily BSD. SunOS 5 is primarily System V, with some 'leftovers' from earlier releases. [My guess would be that the BSD bits were left in primarily for backwards compatibility or because SysV didn't have equivalents.]

In any case, modern Solaris is much more SysV than BSD.

Re:Divide and conquer

[Kent Recal]

"too useful to be moved to ports" (bind, sendmail)

Useful, eh?

Re:Divide and conquer

[Anonymous Coward]

Apropos startup scripts, do BSD people even understand SysV-style inits? Sometimes one gets the impression it is just a step too complicated or something.

I was Solaris SysAdmin for four years. And SysV-style inits only ever got in the way. Having learnt all about SysV run levels, the fact that I can hardly remember a thing about them surely tells us that this is not really a significant BSD/SysV differance.

The new style rc scripts BSD are not perfect. But in my opinion are just a tiny bit less irritating than SysV. BSD scores because it's a developing system... so the irritations will grow smaller.

And methods, and quirks to learn. And they sooner or later reinvent the same things. Not necessarily an advantage.

Indeed, but not necessarilly a disadvantage either. By your argument there should be one Linux distro. Competition breeds innovation. End of argument.

I mean, there's a reason why all the BSDs make an effort to run Linux binaries, not the other way around.

In my book that makes Linux look bad. If Linux truly is the ultimate operating system, it would be nice if it was atleast partially compatible with BSD.

The BSDs freely admit they lift stuff from Linux because that stuff is a good idea. From your comments looks like it would be hard to persuade you to lift anything from BSD... no matter how much of a good idea it happened to be.

The way I see it, BSD users who want nothing but a decent OS and a quiet life. Linux users want a religion, and to fight holy-wars. Seeing as I don't argue religion publically, please excuse me for posting anonymously.

Re:Divide and conquer

[Anonymous Coward]

hold on cowboy...
linux drove usb support? check your history...

USB support in both of these evolved around the same time (kernel 2.2 / FreeBSD 3.0). There are more drivers available for Linux though.

linux has better support for smp? right... 'cos the linux smp support isn't a rip of free-bsd's first smp incarnation

Woah, way to rewrite your history. Linux was first to even have SMP support in 1996. FreeBSD followed in 1998. Linux developers steadily worked on improving SMP, causing Matt to note that Linux was about a year ahead in 2001. Around the time that FreeBSD decided to import SMPng from BSD/OS in an effort to keep up.

and free's 'new' smp code is some hack up by a big school kid is it?

I didn't claim BSD was in any way bad. Heck, I've been a long time fan myself. I simply noted that Linux drove development.

linux has better support for enterprise hardware? shall we start with... i dunno... scsi support... get your history book out and do some experimenting with old linux v's old *bsd installs - try backing up a raid and restoring, then come back and tell me how good scsi isn't fundamental enterprise computing...

Can you be any more specific? This seems a vague generalisation. Certain cards and drivers have had more problems than others. You make it sound as if Linux SCSI support was unusable. What about today? Would you call SCSI support under Linux unstable? And where is BSD when it comes to support for such things like NUMA, or the 256 processor boxes SGI is starting to sell?

next you'll tell me that open's code auditing and goal of bug-free secure code is inferior to linux's free for all crap-code fest

That has nothing to do with what I said. But now that you mention it, yes, in some ways it is. OpenBSD development does not proceed as briskly as that of FreeBSD, let alone Linux. By choice. And that's fine.

excuse my rant, i'd don't mean to bag linux - every OS has its place - even windows.

but man... linux zealots and their damn superiority complex, re-writing history... i even heard someone try to explain the sco crap the other day... he actually said that 'unix is a brand of linux'

You can't blame me for the misguided views of other Linux users. There happen to be a lot of them. Similarly, I might say that it is amusing that many BSD fans seem to have the need to call Linux crap, cruft and bloated and would never acknowledge the many good things that it has going for it.

Re:Divide and conquer

[Anonymous Coward]

linux zealots and their damn superiority complex

BSD assholes have their own superiority complex, and your post is evidence enough. But this will get modded down to oblivion by you BSD snobs, but I want to say it anyway. It's obviously OK to call us "Linux zealots"... talk about hypocritical double standards.

Re:Divide and conquer

[Anonymous Coward]

The difference is, Linux people don't feel the need to bend the truth and mislead. Sure there are a bunch of idiots who post outright stupid trolls, but very few who half know what they're talking about attempting to slip FUD in with the facts.

FUD? Yeah like the stability and security and scalability and performance under load crap. And this isn't a few "years old" remarks, open your eyes, the BSD mailing lists are full of this crap.

(Sorry, post is directed mainly to the grandparent)

Re:Divide and conquer

[Strog]

Just a FYI here.

USB was backported to the Linux 2.2 kernels from the 2.4-pre kernels during the first half of 2000. NetBSD added initial USB in July '98 and FreeBSD ported it over shortly after. FreeBSD 3.1 Release (Oct '98) was the first *nix release to have USB support of any kind(though only mice and keyboards).

Just my 2 cents

Re:Divide and conquer

[Anonymous Coward]

SVR4 (on which SunOS 5 was based) was a 'unification' release, which aimed to re-unify BSD, Xenix and System V. System V was obviously the core of the new system (the System V kernel was much more advanced in terms of SMP, etc.), but SVR4 definitely wasn't 'just another System V release'.

If you remove BSD from the picture, you lose things like sockets, job control, even basic tools like vi. BSD also introduced things like paged virtual memory and a usable interactive shell.

Overall, the Solaris kernel is based on SVR4, but if you take BSD and the BSD-originated features out of SVR4, it becomes an almost completely useless system.

Re:Divide and conquer

[Anonymous Coward]

"I mean, there's a reason why all the BSDs make an effort to run Linux binaries, not the other way around.

In my book that makes Linux look bad. If Linux truly is the ultimate operating system, it would be nice if it was atleast partially compatible with BSD."

Lets see. FreeBSD can run Linux apps. NetBSD can run Linux and FreeBSD apps. OpenBSD can run Linux, FreeBSD, and NetBSD apps.

I bet if you graphed that against number of users, you might find something startling. Well, startling to you at least, blindingly obvious to everyone else.

Not by a long shot.

[Tony-A]

"The reason for this excitement is that it is becoming clear to us that we can develop very clean-looking, elegant, debuggable, SMP scaleable software using this model whereas using the mutex model generally results in much less elegant (even ugly), difficult-to-debug code. Code complexity and code quality is a very important issue in any large piece of software and we believe we have hit on a model that directly addresses the issue in an SMP environment without compromising performance."

I don't really know what he's talking about, but:
If he's right, everybody wins.
Even if he's wrong and we find out why, everybody wins.
It sounds like Linux isn't hurting BSD any, and methinks for a number of reasons, Linux wouldn't be what it is today without the BSD's.

Re:Not by a long shot.

[Anonymous Coward]

> a number of reasons, Linux wouldn't be what it is today without the BSD's.

That's true. Linus hung out in the BSD maillists for a while and learned how not to run a project.

Re:Not by a long shot.

[Anonymous Coward]

Yes. Where as BSDs are jointly run by the contributors, in quasi-democratic fashion, Linux is a one-man show. What Linus says goes, since the he owns the right to the name 'Linux' (in contrast, none of the BSD projects own the 'BSD' name itself).

Linus didn't seem to learn the biggest lesson, though, which is don't be sued by the idiots who currently own the UNIX source code. :-(

Seriously, though, BSD contributed at least as much to UNIX as we know it as AT&T did, and all UNIX-like operating systems owe a lot to it (even if Linux is a more popular platform for new development on UNIX-like OSes now).

Linus Torvalds even said that he wouldn't have started Linux if he had been able to get hold of BSD. 386BSD, however, wasn't finally released until 1992, and then the USL lawsuit held it and its successors (NetBSD/FreeBSD) up for another two years. By 1994, Linux had reached the 1.0 stage, and there was no pressing need to switch to BSD (BSD was more advanced, but so what; either one got the job done).

SSI?

[convolvatron]

cluster-capable system implementing native SSI (Single System Image) which is something that no other operating system can do today

umm...unicos/mk?

Re:SSI?

[Kaladis Nefarian]

If you read the article, Matt says (about SSI): "It is something that no non-commercial system today can do"...

Re:SSI?

[javiercero]

Nope, Unicos/mk runs on the T3D/E machines which are not a cluster. Same for Irix or SUN, their SSI scalability is based on NUMA machines not clusters.

Re: SSI?

[Anonymous Coward]

DragonFly is being redesigned at it's core to allow this sort of clustering, whereas Linux's clustering software is tacked on third party cruft. DragonFly will have native clustering capability soon, and it will be at a level equal to that currently in Linux (although built-in).

The ultimate goal of which Matt speaks will go far beyond even that, and it'll take time. For Linux to do the same thing, they'd basically have to reinvent their kernel as Matt has done with FreeBSD's, and that's not about to happen.

Learn to think.

Re: SSI?

[Anonymous Coward]

Nice try tit. Linux has no native SSI, whereas DragonFly's implementation is being built in. Fuck yourself Linux cruft evangelist boy.

Re:SSI?

[funwithBSD]

Yeah, rules out OpenVMS too...

I am always amazed at the rockin' shit OpenVMS can do... just about everything that DragonFly is suggesting... plus the fact that a hacker that got in would likely just say WTF? and log out.

Re: SSI?

[Anonymous Coward]

I didn't say Linux had native SSI, fuckwit. Learn to read you illiterate imbecile.

I see you still can't back up that earlier shit that you vomited except with some more sloppy shit. You must really enjoy swimming in it. Ha ha.

Re: SSI?

[Anonymous Coward]

God damn, you are a dumb cock sucking cumbucket Mr. Linux lover! This *IS* a BSD article after all. Fcuk off with your Linux garbage!

Re: SSI?

[Anonymous Coward]

With the last of his FUD exhausted, we see the BSD advocate is reduced to a spluttering retard when challenged for facts.

Is your brain too slow to come up with a coherent retort, or aren't the facts on your side? Calm down before you give yourself a stroke you poor spastic. Ha ha.

Re: SSI?

[Anonymous Coward]

I agree, you are an idiot...

Re: SSI?

[Anonymous Coward]

Nice comeback.

Re: SSI?

[molnarcs]

I don't think the parent post warrants such an outburst. You obviously need to see a doctor. Yes, now and then the items on your list (BSD is cleaner, more organized, etc..) do come up, but then, what the hell does operarc and mplayer.conf do in /etc??? (sorry, I couldn't resist :-P)

You need to take a break IMHO.

Jesus fucking christ give it a fucking rest already please? Just go about your BSD stuff and be happy. Just constantly rubbishing Linux at every opportunity just makes you look like an imbicile with Linux envy.

It seem it is you who has some sort of imbecile rage against BSD, as if it killed one of your relatives or something. Saying things like 'this will be better than what linux has or will probably have' shouldn't throw you in such a fit. Look. Matt might be up to something. He might succeed. He might not. Either way,(even linux) developers might/will learn something from this 'experiment'. Can't hurt, right?

Now go, fetch that valium before you have stroke.

ps: (modded as insightful? - come on ...)

Re: SSI?

[Anonymous Coward]

It seem it is you who has some sort of imbecile rage against BSD, as if it killed one of your relatives or something. Saying things like 'this will be better than what linux has or will probably have' shouldn't throw you in such a fit. Look. Matt might be up to something. He might succeed. He might not. Either way,(even linux) developers might/will learn something from this 'experiment'. Can't hurt, right?

No I don't have a rage against BSD at all. I don't know much about them but I know they're generally pretty good systems. I prefer Linux, but I don't feel the need to always point out how something is or will be better than what some BSD has.

I can understand some people like to point these things out though, and that is fine EXCEPT when they are wrong or just have no idea what they are talking about, like the OP.

"Although I don't have any measurements, Linux's scalability on NUMA systems should be greater than FreeBSD's presently is, because of Linux's NUMA aware memory allocation and scheduling"

Something like that I don't have a problem with (assuming no blatant lying about the facts).

"Linux's SSI is only a crufty third party addon and they'd have to completely rewrite the kernel to match the quality of DFBSD's SSI implementation"

I take issue with this because it is blatant FUD spreading from someone who must surely know they don't know what they're talking about.

Re:SSI?

[Anonymous Coward]

I Guess this does it most http://www.openssi.org

Re:SSI?

[Alan Cox]

And to a great extent also things like MOSIX, which go back to V7 unix as well as Linux. Also for that matter OpenSSI (openssi.org)

The commercial world is full of SSI systems although its never been clear if transparent SSI is the right answer to any problem except "I need it to work now", because coding good apps for SSI setups is hard.

Dragonfly looks a good project, and looks like it has old BSD folks who actually knew what they were doing working on it.

Re: SSI?

[molnarcs]

"Linux's SSI is only a crufty third party addon and they'd have to completely rewrite the kernel to match the quality of DFBSD's SSI implementation" I take issue with this because it is blatant FUD spreading from someone who must surely know they don't know what they're talking about.

Ok, I myself might have been a bit harsh in my post. But look around. If you compare the level of atrocity BSD users are exposed to around here (and even osnews), that post wasn't even close to being a troll. I don't think criticism is bad. There are many things in linux that are better than in BSD. As far as I can tell, few among as have issues acknowledging that. But when it comes to thing in which BSD is better (parent post didn't even say that, it said that dfybsd will be better) people cry FUD. This isn't good for linux.

You see, I switched to FreeBSD half a year ago. Before that, I was migrating from distro to distro (RH7.3 --> MDK 9.0 --> 9.1 --> Debian) but now I am satisfied. But when I am asked why is that, I learned that I can only say that it is just 'personal'. I like BSD better. Whenever I am about to disclose more tangible reasons, no matter how diplomatic I am, someone's feeling get hurts, even if I can support every claim I make.

About clustering. He might not have been very diplomatic, but are you sure there isn't some truth in what he said? I ask this, because we built a small cluster here on campus, based on Mandrake's CLIC linux - which is all about clustering, isn't it? But what we found underneath (you can check out the ISO if you don't believe me) was ... well linux + 3rd party cruft. Even the kernel wasn't any different than the 'enterprise' kernel shipped with the stock (9.0) Mandrake CD (2.4.19). All mandrake did was add some scripts that automate deployment (installation of the 'golden' node with automatic dhcp configuration, replication, and _3rd party software_ configuration). All that software - ranging from GANGLIA monitor to PVM - is readily available for FreeBSD. And no, it isn't better on FreeBSD. A FreeBSD cluster is FreeBSD + some 3rd party 'cruft' (just like linux at the moment).

This is one of the point by which Dragonfly BSD distinguishes itself from the other BSDs - and linux. For christ's sake: its free software, GPL compatible and all. If they succeed - no one will 'loose' even if dfybsd will be better in clustering than linux.

Re: SSI?

[Anonymous Coward]

Ok, I myself might have been a bit harsh in my post. But look around. If you compare the level of atrocity BSD users are exposed to around here (and even osnews), that post wasn't even close to being a troll. I don't think criticism is bad. There are many things in linux that are better than in BSD. As far as I can tell, few among as have issues acknowledging that.

Yeah it is pretty sad the amount of crap that BSD users put up with here, but to say they don't have any part in bringing it upon themselves is naive. OK it isn't every BSD user, but so many of them just continually make snide (and usually untrue) remarks about Linux while discussing their operating system. You have virtually none of this in the Linux community.

There is a very strong anti-Linux feeling from all levels of the BSD community. Yes, even the kernel hackers. The irony is lost on them when they think themselves extremely clever and funny when making up things like "Linux is for people who hate Windows, BSD is for people who love UNIX".

Linux has its share of vocal anti-BSD people, but they don't permiate the whole community.

But when it comes to thing in which BSD is better (parent post didn't even say that, it said that dfybsd will be better) people cry FUD. This isn't good for linux.

But parent said it in an inflamatory way. And he obviously can't say why Linux kernel would need a complete rewrite (hint: it wouldn't), nor why the third part addon is "cruft" (except that it isn't in the base kernel).

Re: SSI?

[molnarcs]

"There is a very strong anti-Linux feeling from all levels of the BSD community."

I don't know why you say that. Care to point out where can you see serious linux bashing sessions in the BSD community? (I'm not interested in years old derogatory statements/jokes). BSDforums has its own linux section, for instance. Occasionally linux newbies post there - and you won't see 'hey, use bsd instead' remarks there. People simply try to help. Or just a few minutes ago I saw this post - talking very positively (gasp!) about a linux distro in the middle of bsdforums (gasp again!) - and see the replies? No flames - just friendly discussion.

Now, on the other hand, I could point you to gentoo-forums posts that are very much against the BSDs. I think what you try to do here is simply smear the bsd community with FUD - the 'examples' you give are years old (and at that time, linux was in its infancy, so some things might have been even true - no offense). I myself came from a Mandrake background btw - which has an excellent community, both on mandrakeusers.org and pclinuxonline. And the FreeBSD community was as welcoming and tolerant to my early blunders that any linux distro would be proud for such a great user community. (I never saw RTFM posts - even if someone blatantly ignored/refused to read any documentation, the excellent handbook was pointed out as an important resource in a civil manner).

Re: SSI?

[Anonymous Coward]

You pediphilic dog fucker ;p

Re: SSI?

[Anonymous Coward]

I don't know why you say that. Care to point out where can you see serious linux bashing sessions in the BSD community? (I'm not interested in years old derogatory statements/jokes). BSDforums has its own linux section, for instance. Occasionally linux newbies post there - and you won't see 'hey, use bsd instead' remarks there. People simply try to help. Or just a few minutes ago I saw this post - talking very positively (gasp!) about a linux distro in the middle of bsdforums (gasp again!) - and see the replies? No flames - just friendly discussion.

No, I didn't say every BSDer is anti-Linux, or even most of them. And the above example is quite interesting, because every BSDer will freely admit that their OS might not be the easiest to set up.

Submit a post there asking which of Linux or FreeBSD should be used for a high performance server? Which is more stable? Which has a higher performance networking stack? Which is more scalable? Etc etc.

Now, on the other hand, I could point you to gentoo-forums posts that are very much against the BSDs. I think what you try to do here is simply smear the bsd community with FUD - the 'examples' you give are years old (and at that time, linux was in its infancy, so some things might have been even true - no offense). I myself came from a Mandrake background btw - which has an excellent community, both on mandrakeusers.org and pclinuxonline. And the FreeBSD community was as welcoming and tolerant to my early blunders that any linux distro would be proud for such a great user community. (I never saw RTFM posts - even if someone blatantly ignored/refused to read any documentation, the excellent handbook was pointed out as an important resource in a civil manner).

Well I didn't say Linux community has no BSD haters. You claiming that the BSD community has no Linux haters?

Now on the other hand, search the linux kernel mailing list. All recent posts mentioning BSD are without bullshit, whining, fighting, FUD. Do the same on the FreeBSD lists and see how much their kernel hackers bash Linux.

Re: SSI?

[molnarcs]

"Submit a post there asking which of Linux or FreeBSD should be used for a high performance server? Which is more stable? Which has a higher performance networking stack? Which is more scalable? Etc etc."

Submit the same post on a linux forum ;) I don't believe anyone on bsdforums would tell you to install bsd on a >4 processor machine (because they won't recommend the 'new technology release' of the 5.x series, and SMP in 4.x simply sucks. As to stability/security: YMMV. And opinions may vary. Linux is as secure as an admin makes it - and it can be as secure as FreeBSD. In My Personal Experience(tm) it was easier to set up a secure FreeBSD than to secure a linux distro (even Debian). That's because the FreeBSD command line (man pages, system layout, config files) are very easy to read and edit.

Of course, giving my reasons for saying that would need a much lenghtier elaboration of this, but a short example: the FreeBSD firewall, ipfw. It has an almost english syntax:

ipfw add 1000 permit all from me to any out via rl0 # this will permit every outgoing
# connection from my machine via a specific interface.
# I could have also written:
allow ip from <my ip address> to any xmit rl0 #or
pass ip from ... #you get the picture
# and here is how it looks like when you create a stateful firewall rule:
check-state
ipfw add 1000 permit all from me to any out via rl0 setup keep-state

another example: blackholing your puter

sysctl net.inet.tcp.blackhole=2
sysctl.net.inet.udp.blac khole=1

Of course, I can say FreeBSD was easier to set up for me given the specific purpose of that machine. At the same time, I agree with the Mandrake post, inasmuch as Mandrake is a far better solution if you want to replace your XP with a free OS, but don't want to deal with the CLI.

So yes, some points might create disagreement in discussing linux vs. freebsd. But there are multiple ways dealing with the issue. For instance, one could say: "the linux console driver sux0rz" This is Very Bad. Or one can say: There isn't separate scrollback buffer for each terminal. When you switch, it gets erased. As a result, it is easier to select a portion of screen output (without using 3rd party application) with a mouse, and paste it in an editor on another terminal. Moreover, you can set the scrollback buffer to an arbitrary number of lines.

Both descriptions have some truth in them. But I would undoubtedly label the former as trolling while the latter as informed (informative). Between the two, there are myriad ways to express this difference. It is up to your individual taste to decide on the point that makes it flambait/trolling. As to the post that lead to this discussion: I don't like the grand(grand-grand) parent's post. But it is my opinion that the reply describing it as flamebait was much more a flamebait than the original. Implicitly (and it wasn't that implicit) it suggests that the BSD community at large is what he perceived the parent post's attitude to be (putting words in his mouth that never left it).

Back to your original suggestion. I can point you to many linux related questions on that forum (the example above is not uncommon or outstanding in any way). And the usual reply to such questions isn't something like use BSD instead of linux. In fact, old time BSD users would recommend linux (on bsdforums!) if they know BSD doesn't suit the task at hand. Here is an example for that. Abe_the_Man probably went for a linux solution (seeing how he didn't post there anymore) - and as you can see he was recommended to use linux on bsdforums. In this post you can see many positive rem

Re: SSI?

[Anonymous Coward]

"Submit the same post on a linux forum ;)"

They wouldn't try to claim stability or security without facts. They might be able to point out that Linux has better scalability and performance in some tests.

"Of course, giving my reasons for saying that
would need a much lenghtier elaboration of
this, but a short example: the FreeBSD
firewall, ipfw. It has an almost english
syntax:"

I don't know why so many people are so caught up in these firewall rules things. If they were really that useful, then someone from Linux would have made similar sort of front end to Linux's packet filtering. The hardest part about a firewall is not the syntax, but I digress.

[ your bsdforums post examples ]

Well the first basically says "there are no drivers for BSD so you have no choice than to use Linux", the second basically starts with the question "what Linux distro should I use?".

So in neither thread is there even the opportunity to use BSD.

"So my issue with the post to which I replied
to was that it does a huge injustice to the
bsd community, even if there are jerks who
attack linux the way he described. But I
strongly disagree with the implicit assumption
that the BSD users (in general) are like
that."

OK, I admit my attack made me as bad as the anti-Linux trolls. I apologise.

Re: SSI?

[Anonymous Coward]

Yup. I had to scrape your mouth for it you shit swilling goat bugger.

Michael

[LittleLebowskiUrbanA]

What w/ the laziness and impatience remarks? Just can't help making a dig at anything not Debian?

Re:Michael

[Waffle Iron]

I think it was intended to be a complement, as in:

"The three chief virtues of a programmer are: Laziness, Impatience and Hubris." -- Larry Wall

Amazing.

[xeeno]

There's actually something on the front page about BSD. And it says nothing about SCO or linux.

Re:Amazing.

[JDWTopGuy]

And no dupes!!

Something no other OS can do?

[fmayhar]

It's simply not true that "a transparently cluster-capable system implementing native SSI" is "something that no other operating system can do today." We were doing it at Locus in 1994 with SVR4 then with Tandem in 1996 with NonStop Clusters for Unixware. Now some of the same folks at HP have introduced OpenSSI, which is essentially the same code, less all the Unixware-related bits, ported to Linux and placed under the GPL. They are coming up hard on their 1.0 release, which is not bad for five people and such a large task.

OpenSSI is the real thing, it has processes that migrate from node to node, distributed file systems, the works. And it's running now on clusters literally all over the world. (Not many clusters, true, but maybe that will change if the Slashdot crowd finds out about it.)

I'm happy to say that there's a lot of my code in that system, as well.

I know a little about what Matt wants to do with his SSI in Dragonfly, but he should certainly take a look at OpenSSI; we had to solve a lot of the problems you run into when you build such a beast.

(And a beast it is. As complex as a kernel can be, when you have what is essentially a distributed kernel across several nodes, the complexity goes up by orders of magnitude. Makes tracking down those weird hangs pretty exciting, in a painful, time-consuming kind of way.)

Re:Something no other OS can do?

[CoolVibe]

It's just Matt aiming high. He doesn't care if he (and others) achieve it, but it would be choice if he would. The ultimate goal would be to achieve such a thing without much hassle, but we do know better. It just gives us something to aim for.

Re:Something no other OS can do?

[Anonymous Coward]

same folks at HP have introduced OpenSSI, which is essentially the same code, less all the Unixware-related bits, ported to Linux and placed under the GPL.

This looks like much stronger grounds for a lawsuit than anything IBM did. Kiss your UNIX licence good-bye HP!!

Re:Something no other OS can do?

[fmayhar]

Not so much, no. The bits that were ported were never tainted and the bits that were tainted weren't ported. Because of the way we did our development, what belonged to us was never mixed with what was merely licensed. So when I said "strip out all the bits related to Unixware" I meant precisely that. Not "strip out all the Unixware bits" but strip out all the stuff in the locally-developed code that was Unixware-specific.

Of course, I was only there for the very beginning of the port; by the time the code was placed under the GPL I had been at BSDi for a while.

Re:Something no other OS can do?

[Anonymous Coward]

It's simply not true that "a transparently cluster-capable system implementing native SSI" is "something that no other operating system can do today."

He didn't say that, here's the paragraph from the interview (emphasis mine)..

Well I strongly believe that any project needs to have an unattainable goal, and our unattainable goal (which I hope actually winds up being attainable) is to develop DragonFly into a transparently cluster-capable system implementing native SSI (Single System Image). It is something that no non-commercial system today can do (the type of clustering Linux supports isn't even close to the type of clustering that we have as our goal, and clustering has never been one of the other BSD's goals as far as I can tell).

Re:Something no other OS can do?

[fmayhar]

"Learn from," not "take code from."

(Sigh, kids these days, whatta ya gonna do?)

Re:Something no other OS can do?

[Anonymous Coward]

"OpenSSI" is not open...it's GPL'd, don't look at it :(.

Re:Something no other OS can do?

[Sri Lumpa]

Same with IBM and AIX but somehow it didn't stop SCO claiming that IBM's code couldn't be licensed under the GPL.

As for OpenSSI, is it an integral part of the Linux kernel?

If not then it isn't really native given that it is a third party add on to Linux (or we might have a different idea of what native means in this context).

Same with your Unixware example, if it uses a third party product then it isn't really native.

Now, is there an OS out there that natively* implements SSI? (not a rethorical question, I would be interested to know).

*IOW: without third party modifications.

The Ballad of Matthew Dillon

[Anonymous Coward]

The once was a fellow named Dillon
Whose Dragonfly project was illin'.
He found, to his dread,
His *BSD dead
And Linux was doin' the killin'.

Re:The Ballad of Matthew Dillon

[ScrewMaster]

Aw, come on. Somebody mod this guy funny.

I guess I'm the only one that likes limericks around here.

Re:The Ballad of Matthew Dillon

[kfg]

There once was a Master of Screws
Who thought it most wonderful news
That the AC's post
was more funny than most
But not all mods agreed with his views.

KFG

Re:The Ballad of Matthew Dillon

[ScrewMaster]

Apparently, the mods have decided that I was right after all. The original is now a +5 Funny. Cool. But I like this one best. "Master of Screws". I like the sound of that.

Re:The Ballad of Matthew Dillon

[JDWTopGuy]

A fellow of nick KFG
Saw ScrewMaster's prose
And rhymed thru his nose
But the joke was a crime
And I'm out of time. Phooey.

Re:The Ballad of Matthew Dillon

[VValdo]

There once was a fellow named Dillon
Whom everyone thought was a villain,
He cried, "That's not me!"
"I use BSD!"
"Because I find it fulfillin'."

W

Re:The Ballad of Matthew Dillon

[Anonymous Coward]

KFG, did you realize that you're not funny? You've just got way too much time on your hands...

Re:The Ballad of Matthew Dillon

[Ziviyr]

I thought "BSD is dead" posts were rudundant..

Re:The Ballad of Matthew Dillon

[Aeonsfx]

ROFL, this guy might be a troll, but he's a damn clever one at that... ;)

Linux has no SSI?

[Anonymous Coward]

Funny, the Slashdot blurb accuses him of saying that no other system today does SSI, while according to the article he simply said their (future, potential) SSI plans will beat Linux's (present, working) SSI clustering.

Anybody have thoughts comparing the DragonFly SSI(warning, PDF) and the Linux one?
(Open)Mosix has had craploads of work done on it, and by the time DragonFly's is done, it will be even further ahead. I somehow doubt DragonFly's will end up being better.

PK

Re: Linux has no SSI?

[Anonymous Coward]

I believe that Matt meant out of the box for one, and native for another. "Linux's" SSI is a third party package that is not exactly seamlessly integrated into the kernel, nor does it seem like it will be any time soon. Such would take the kinds of fundamental kernel alterations that are going into DragonFly, and I seriously doubt that Linus is up for that at the moment.

Re:My first question would be...

[Anonymous Coward]

I thought that was funny.

Re:So I looked at OpenSSI's website. ..

[Bastian]

. . . and read their brief overview at the top of the page.

And it almost made no sense to me. Those buzzwords work great one at a time, but the brain starts to make a noise kind of like the one the TV makes after the TV channel goes off the air when you string too many together at once. Especially when nothing but commas separates them.

Did anyone at HP's marketing department take an courses in English at college? Or were they just as non-clueful about what OpenSSI is when they wrote that blurb as I was when I first went to their website?

Someone should tell them Kant already has a patent on writing paragraphs that take as long to read as pages.

Re:QT4co

[Anonymous Coward]

I agree with your coherent statement.

Package management

[Anonymous Coward]

The nice thing about BSD is that if you have it installed on a 3GHz machine, and you have about 500-800 ports on your hard drive, then to keep then current, you can compile all of them from source and spend only about 50% of the CPU time doing it, on average. The other 50% are yours to use! Yay!

If you do not keep them current, you may be missing out on some important security fixes.

Re:Where to turn for help with your BSD problems

[Anonymous Coward]

That's the first time I actually see a BSD user offer advice, other than read the handbook or man pages. Well done.

Re:Very interesting!

[null-sRc]

>I'm surprised people still use BSD after that
>security fiasco last year.

so what do u suggest windows? LOL
sorry ;)

Backplane non-free, non-relational

[leandrod]

This SSI stuff sounds interesting, but I'd like to see his stuff compared to OpenSSI. Now the Backplane SQL DBMS seems interesting, but... First, they make the common mistake of calling SQL relational. This in itself will prevent them becoming significantly better at the logic level, which is a pity. Second, it looks very interesting as far as the backend goes. But the question here as always is, why create something from scratch? Couldn't, say, PostgreSQL, which was born on BSD anyway, be retrofitted with their stuff? Won't Oracle or IBM leapfrog them if they prove successuful? Third, looks like we have yet another BitKeeper in the making... gratis for free software, but not free itself. Makes me want to stick with PostgreSQL for now. If I wanted something proprietary, I'd go Alphora Dataphor, which at least is fully relational and not yet another SQL.

Re:Backplane non-free, non-relational

[Christopher B. Brown]

Backplane has all of the licensing downsides to MySQL; it looks as though they have taken their policies direct from MySQL AB. And where MySQL has been able to get a cycle of "bait and switch" in to hook people on the product before hitting them up with the real license, Backplane has been quite up front about the product being intended as a "we charge you if you use it" one, which will certainly discourage people from donating free effort to it.

It's an interesting system in that it is really quite different from all the other SQL databases.

Unfortunately, as you suggest, its approach is quite opposite to being relational. It would be interesting to see something based on Tutorial D. There are a couple of projects on SourceForge, but neither are at all useful at this stage. The appropriate approach would probably be to implement a Tutorial D language atop PostgreSQL. After all, that's the approach Dataphor takes; it implements D4 atop Oracle or DB/2.

Re:Backplane non-free, non-relational

[leandrod]

Backplane has all of the licensing downsides to MySQL

Well, I don't consider copyleft a downside. But the Backplane license does not seem even to be free.

> The appropriate approach would probably be to implement a Tutorial D language atop PostgreSQL. After all, that's the approach Dataphor takes; it implements D4 atop Oracle or DB/2.

Actually Dataphor isn't implmented on top of anything. It just uses an SQL DBMS. AFAIK they don't intend yet to have their own, nor integrate into any, DBMS engine; they are still doing homework on the tools. Right now they define Dataphor as a virtual RDBMS.

I agree about PostgreSQL. After all, it was once a RDBMS; it would be but a return to its roots. But the Alphora people didn't have a good impression of PostgreSQL, based on some v6 deficiency. OTOH Backplane seems an interesting approach to distribution, and could be useful if freed. Obviously what applies to Backplane at the physical level applies equally to Dataphor at the logical: it just should be free.

License contradiction?

[XaXXon]

If your application is licensed under the GPL or compatible OSI license (learn more at opensource.org) approved by Backplane, Inc., you are free and welcome to ship the Backplane open source database with your application.

followed by:

If you power an application using the Backplane database that you market or sell, or use that application to conduct any form of online commerce (selling/buying products or services over a website) you need to purchase the Backplane Commercial License.

The example given is if you run an email service from which you sell access to other companies, you must buy the commerical license.

My question is, what if the program that provides the email service is GPL. Do I have to buy a commercial license or not? One of the great things about GPL software is that if it's an internal piece of software, you can mix proprietary and GPL code as much as you want, as long as you never redistribute the program to anyone.

Also, how does dual licensing work with this? Can I license it under the GPL to myself, and then sell copies under another license to other people? Obviously THEY would have to buy a commercial license, but do I?

Just trying to point out some holes in the licensing..

Oops, just noticed the part at the end saying:
NOTE: In any of these examples, if the entire application or service is 100% GPL compatible, you may use the Backplane Free License.

But that still leaves open the question about dual licensing..

lowest score first

[Anonymous Coward]

this is one of those articles that I wish I could sort by lowest score first. well that's any BSD article I guess.

Re:not to mention the more recent security holes

[Anonymous Coward]

It's just because there are actually more people willing to write GPL/Linux software than willing to write BSD licensed software for Microsoft.

Sorry that's supposed to be "Apple and Microsoft" not just Microsoft. It's been a long night and I was kinda tired when I typed that last comment :)

Re:My first question would be...

[Anonymous Coward]

yes, but you are an imbecile

Re:Don't forget the occasional Ceren pix post /nt

[Anonymous Coward]

Actually, yes.

Reading through all this stuff just to get a link to one of those red devels !!
Go anyone post one, please.
BSD is dying except of its ladies.
Not too bad .... !

Patents

[fjpereira]

Hei, Dillon

It seems that you are working in some
inovative features.

I hope that in the way, you fill some patents
about your work (even if you don't agree with
software patents), because we are going to
need it in the upcoming patent fight against
Microsoft.

Re:Patents

[AntiOrganic]

Prior art will invalidate a patent. No one needs to patent a damned thing.

Re:Patents

[DashEvil]

I'm going to patent this prior art thing you speak of, and then we'll see who does the invalidating!

Is this just MACH?

[jasonsingha]

It sounds an awfully lot like they are planning to build a Mach kernel with message ports and everything.

Maybe he should fork Darwin instead and then I could run it on my iBook. ;)

Dillon?

[Anonymous Coward]

Hey isn't that the guy who wrote dcron?

SunOS ISA BSD, Solaris ISA SVR4

[BuildMonkey]

SunOS had its roots in BSD. Solaris has it roots in SVR4. The changeover happened in the '94-'95 time frame.

Opposite of "advanced"

[Doug Merritt]

This is Slashdot, where any sufficiently advanced opinion is indistinguishable from fact. ...A sufficiently advanced opinion is a fact. [...] At which point it becomes hindsight, and no longer quite so advanced.

In technical jargon (e.g. wave theory), the opposite of "advanced" is "retarded".

Re:Here is an exact copy of point 7, para. 3:

[greentree]

i hope that metamoderation will fix it. but eh, shit happens.

Arrogant comment...

[jrnchimera]

Matt said...

Keep in mind that developers work on the BSDs for very different reasons then developers who work on Linux. The BSDs are all about advancing software technologies into new arenas, while Linux is all about leverage (which is why you see a very well integrated security subsystem in FreeBSD-5 and OpenBSD and ten different types of filesystems in Linux).

This sounds very arrogant to me. Is he really suggesting that the BSD's innovate while Linux development does not?

Re:Arrogant comment...

[Anonymous Coward]

Not saying this is the case with Matt, but some BSD people have a case of sour grapes because of Linux getting so much attention and funding from IBM, SGI, etc. so they try to spin that every way they can.

They don't realise Linux has attracted as many if not more hobbiests and researchers as BSD.

Re: Arrogant comment...

[Anonymous Coward]

Don't be silly. Linux certainly does innovate, and he is not the sort to bad mouth folks for the hell of it, and he most certainly does know what he is talking about.

The BSDs *ARE* more integrated environments than any Linux distributions I've ever used, and I've used a lot. Different focuses really, the BSDs are meant as end to end solutions, whereas Linux is really meant more as a component for folks to 'make their own' OS.

Re:Arrogant comment...

[Chauncy]

Yes

Re: Arrogant comment...

[Anonymous Coward]

For once in your life at least try not to be the ignorant tit that your genes have hardwired you to be.

Device drivers

[cant_get_a_good_nick]

It sounds like he might want to look into Project UDI. It's a device driver abstraction that allows source and to some level binary compatible device drivers across platforms with the UDI environment. I did a little work in it, and from a very top level look at his kernel threading model, looks like a good fit with how UDI does things. It's not very well known, and being a Caldera/NewSCO type thing (developed initially way before the current management started the legal stuff) now has political baggage as well.

Moderators?

[Anonymous Coward]

I have no idea why this was not modded up to +5 like the rest of Matt's comments. This new serializing token code is pretty damned interesting as it can do all of the desirable things that mutexes and RCU can do, with nearly none of the headaches (lock order issues, priority inversions, global CPU contention etc.).

Ugh, 'recursive mutex enter.'

Re: Forks

[Anonymous Coward]

You are either so out of line or a complete retard. Linux has far more forks than does BSD. Damned near every distribution uses a non-standard Linux kernel, and those inconsistencies add up to monumental incompatibilites.

I am not against forking, but I am against Linux zealots or those who have been brainwashed by them to continue spreading such rediculous and untruthful garbage like your little tidbit about Linux being fork resistant or BSD being fork prone.

Learn to think.

Dumbass

[Anonymous Coward]

Check out DragonFly itself for an example, specifically it's 'init scripts.' They are taken from FreeBSD 5.x and NetBSD. The only one that does not currently use 'rcng' is OpenBSD, but then we all know that Theo is special.

Fact is that many things are shared freely between all the BSDs once the technology has proven itself to be correct and of value.

You statements are not only laughably incorrect, but downright uninformed and dumb. Perhaps you shouldn't go outside for fear of the evolutionary forking of trees and birds and well, everything else for that matter. It's a frightening Universe for small minds like yours.

Re: NetCraft

[Anonymous Coward]

Heh. The fact that NetCraft shows that GNU.org runs "Linux" must really get their goat ;^)

TWO HUNDRED THIRTY-THIRD POST

[Anonymous Coward]

DEAD