Anyone got any opinions on the quality of SMP support in the various Linux distributions/FreeBSD? All comments welcome.

I've got a dual P3 733 running with RH8.0 and it works nicely.

- Trevor

I've been using SMP on my P2 450mhz tyan thunder 100 motherboard for years now. RH5.x (currently on 7.3). As time has gone on, it's got better and better. I think my uptime is somewhere over 30 days currently (I have power issues where I live, otherwise it would be much higher). It runs 2 seti processes, and is my samba server for my windoze machines. Also does my rsync'ing stuff for my empegs.

I'd love to have a 4/8 way system to try it on. Oh to dream

Anyone got any opinions on the quality of SMP support in the various Linux distributions/FreeBSD?

SMP on Linux just works, right out of the box. Any non-palaeontologically old distro will just work, as will compiling everything from stock tarballs.

I don't know about *BSD, but I'd guess, these days, that a similar comment applies.

Peter

IIRC, only FreeBSD has any significant multi-CPU support.

Edit: References:

FreeBSD (``Symmetric multi-processor (SMP) systems are generally supported by FreeBSD, although in some cases, BIOS or motherboard bugs may generate some problems.'')
NetBSD (only added to -current tree on 1 Oct, 2002)
OpenBSD (``OpenBSD does not currently support multiple processors (SMP), but will run using one processor on a multi-processor system board.'')

If RedHat 8 fell over and died I'd be dancing on the grave...

Linux has relatively fine-grained locking in the kernel. FreeBSD 4.x has SMP support with a small number of mutexes protecting large portions of the kernel, and 5.x has finer-grained locks (I recall; I don't use FreeBSD).

If you want x86 SMP, FreeBSD 5, Linux 2.4, or "no point".

Well, Windows in the NT family (NT, 2000, XP) does reasonable SMP stuff.

SMP has worked great for me in the lab, and that is all the way up to 8 x86 processors, or 4 ia64 procs. All under Linux 2.2 or 2.4 kernels.

I haven't worked with Hyperthreading under Linux yet, so I don't know how much of an issue it is. I do know on the windows side preformace can take a hit if there are multiple physical processors all with hyperthreading, because the OS dosen't know what processor is real and what is virtual.

I had Gentoo on a dual PIII 1ghz box. Ran perfect. It has since been reloaded with Win XP for all my video editing software, and TiVo ripping.

Also, I've got RedHat and Gentoo on a few other dual Celeron machines, and have never had a stability problem. I'd say the quality level is fairly good. I have noticed that the stock RedHat SMP kernels aren't as stable as they should be, but then again, who runs a stock kernel anymore?