Linked by Eugenia Loli on Thu 22nd Feb 2007 23:26 UTC, submitted by Anonymous Reader
FreeBSD FreeBSD has a reputation of being slow in combination with MySQL, especially when compared to Linux. However, some recent improvements in the scheduler shows that FreeBSD now is pretty much on par with Linux. It also shows that Linux scales very badly after a certain amount of threads per CPU.
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Just a question of the operation area
by usr0 on Fri 23rd Feb 2007 00:17 UTC
usr0
Member since:
2006-10-27

The question is whether your system is running more than eight client threads. My web server does not. Therefore Linux is the right choice *for me*.

But if Linux "scales very badly after a certain amount of threads per CPU" why do thepiratebay.org uses a (modified) Linux kernel and not FreeBSD?

Linux was never developed with the intention to be "the OS of choice" just for a particular issue but it was developed to fulfill many needs (desktop capabilities, multimedia, server capabilities) at least satisfactorily. And *for me* it does!

If I should draw Linux I would draw something like this:
http://de.wikipedia.org/wiki/Bild:Wolpertinger.jpg

Reply Score: 5

MightyPenguin Member since:
2005-11-18

To be fair, Linux has stolen the OSS spotlight and so I think any news that a *BSD is still competitive (and in some areas even better) is fair play. I'm a Linux user, but I respect and appreciate the work the *BSD community has done, much of which is used in Linux.

Reply Parent Score: 5

diegocg Member since:
2005-07-08

But if Linux "scales very badly after a certain amount of threads per CPU" why do thepiratebay.org uses a (modified) Linux kernel and not FreeBSD?

I actually would expect linux to work well with *lots* of threads per-cpu, so it's reasonable to expect Linux to work well with two fscking threads, but it doesn't in that test. God knows what linux/mysql interaction or bug is going on here.

Edited 2007-02-23 01:25

Reply Parent Score: 3

butters Member since:
2005-07-08

As the guy said himself in TFA, somebody's gunna claim that he's doing something wrong to get such poor performance on Linux, and that person is me. Not because I refuse to believe the fact that FreeBSD performs better, but because I know for a fact that performance should never plummet like that at such low levels of CPU contention.

When you get such strange results for a benchmark, you have to figure out why before posting them and declaring a winner. Whatever is going on with his particular Linux kernel, it isn't normal. He should retest with a vanilla kernel (instead of the FC6 kernel). I suspect the results will be quite different.

Also, he's doing synthetic benchmarks on his development branch. It's very possible that his scheduler isn't working properly. I can write a scheduler that does great under contention. It would simply select a thread to run on each CPU and never schedule the others. That should give optimal transactions/second with this benchmark.

Reply Parent Score: 5

jimveta Member since:
2006-09-21

When you get such strange results for a benchmark, you have to figure out why before posting them and declaring a winner. Whatever is going on with his particular Linux kernel, it isn't normal. He should retest with a vanilla kernel (instead of the FC6 kernel). I suspect the results will be quite different.

Nonetheless it's still valid for pointing out a problem with a released OS. If it doesn't happen with the vanilla kernel, then the redhat/FC guys should take a look. I would be more suspect if he did tweak some things or compiled his own with patches, etc. but having it plummet like that out-of-the-box is not good.

About the only nitpick then would be to emphasize that this is only known to happen with FC6 so far but I do agree that he should try other kernels.

Reply Parent Score: 1

GMFlash Member since:
2006-06-30

If I should draw Linux I would draw something like this:
http://de.wikipedia.org/wiki/Bild:Wolpertinger.jpg

Your operating system sure looks funny! Someone posted this on ##freebsd freenode a little while ago:
http://img255.imageshack.us/img255/6585/pcmacbsdsq9.jpg

Edited 2007-02-23 14:40

Reply Parent Score: 4

Duffman Member since:
2005-11-23

But if Linux "scales very badly after a certain amount of threads per CPU" why do thepiratebay.org uses a (modified) Linux kernel and not FreeBSD?

The real question here is:
why have they modified the linux kernel if it scales perfectly ?

Reply Parent Score: 3

aliquis Member since:
2005-07-23

Yeah, you are right, Linux is an OS with no obvious goal and a shitload of glue ;)

(No, I don't think it's that bad, but I prefer FreeBSD since I know everyone else runs the same thing instead of random collection of versions and apps, all Linux dists suck ;D, I'd prefer opensolaris with a better distribution than the Sun one thought.)

Reply Parent Score: 1