Optimizations for Xeon E5320?

[KernelPanic]

Any suggested CPU optimizations for FreeBSD 7 i386 system with dual Xeon E5320? Its a Clovertown core with 2x4MB of L2 Cache?

I have none right now. Using Google I found this:

/etc/make.conf
CPUTYPE?=nocona

[graudeejs]

That's probably all you should do...
DO NOT edit any flags
or you will face not only KernelPanics but many different panics as well

build custom smp kernel

[KernelPanic]

Originally Posted by killasmurf86

That's probably all you should do...
DO NOT edit any flags
or you will face not only KernelPanics but many different panics as well

build custom smp kernel

For my custom SMP kernel I suck in GENERIC and then do the following:


# Old CPUs
nocpu I486_CPU
nocpu I586_CPU

# Change the scheduler
nooptions SCHED_4BSD
options SCHED_ULE

# I do not have AGP
nodevice agp

[graudeejs]

Originally Posted by KernelPanic

For my custom SMP kernel I suck in GENERIC and then do the following:


# Old CPUs
nocpu I486_CPU
nocpu I586_CPU

# Change the scheduler
nooptions SCHED_4BSD
options SCHED_ULE

# I do not have AGP
nodevice agp

wth is that?
if you want to disable something from generic
use # to comment line

# Old CPUs
#cpu   I486_CPU
#cpu   I586_CPU 
cpu   I686_CPU 

# Change the scheduler
#options       SCHED_4BSD
options SCHED_ULE

# I do not have AGP
#device        agp

[richardpl]

Wait for 7.1 RELEASE or track 7 STABLE.
Building custom kernel for 7.0 RELEASE is of very little gain.

[KernelPanic]

Originally Posted by richardpl

Wait for 7.1 RELEASE or track 7 STABLE.
Building custom kernel for 7.0 RELEASE is of very little gain.

That is the idea.

[phoenix]

Originally Posted by killasmurf86

wtf is that?

No need to curse. That's the recommended method for those that want to build kernels based on GENERIC, in such a way that any updates to GENERIC are also updates to their kernel.

Just include GENERIC in the config file. Any devices/options you don't want, you disable via nodevice/nooption. That way, when devices/options are added to GENERIC they are automatically added to your custom kernel as well.

See the SMP config file for the include syntax.

[phoenix]

Originally Posted by KernelPanic

For my custom SMP kernel I suck in GENERIC and then do the following:

# Old CPUs
nocpu I486_CPU
nocpu I586_CPU

Leave i586. It enables some in-kernel copy speedup functions. Improves memory allocations and copying of data around in the kernel. Don't remember the specifics of it, but it's faster than just i686.

[graudeejs]

Originally Posted by phoenix

No need to curse.

sorry mate [Shame on me]

[TerryP]

Eh, stupid question...

'include GENERIC' as in the sense of actually puting that in the file, or # cat GENERIC CUSTOM > THEKERNCONF

[phoenix]

Have a look at the SMP kernel config file. It's basically 3 lines: 1 to include GENERIC, 1 for SMP, and one for APIC.

[TerryP]

The generic kernel is an SMP kernel now, but taking a quick grep of PAE, I see what you mean -> sorry, and thanks!

[phoenix]

Hrm, you're right. Somehow I missed that change (GENERIC going SMP).

[richardpl]

Originally Posted by phoenix

Leave i586. It enables some in-kernel copy speedup functions. Improves memory allocations and copying of data around in the kernel. Don't remember the specifics of it, but it's faster than just i686.

Are you sure, do you have more information about this?
Only interesting info I found is about npx(4) and i586, and that is applicable for older machines. I use core2 CPU without i586, and performance is not decreased comparing with GENERIC.

[phoenix]

There's a thread about this from 2005 that shows memory accesses to be faster on P3 CPUs when I586_CPU and I686_CPU are enabled in the kernel config, compared to just I686_CPU.

Doing a google search for "matt dillon I586_CPU" brings up more hits.

It seems I585_CPU enables a few features that I686_CPU doesn't, even on CPUs newer than the Pentium.

[richardpl]

That is obsolete information (there is no hard evidence), but I will explore this.

[TerryP]

Please post back or sort a thread if you turn anything (recent) up richard, thanks.

[phoenix]

It might be "obsolete" in that it is old, but there hasn't been any mention of enabling bcopy and similar operations in the FreeBSD kernel when using I686_CPU. Granted, this may not make a difference on Athlon64/Opteron/Core/Core2 CPUs. I haven't heard/read anything about this subject since that thread, though. Guess someone with access to a few different CPUs will have to benchmark kernels with combinations of I586_CPU and I686_CPU.

[richardpl]

Here is short overview where I586_CPU is used in kernel:

http://fxr.watson.org/fxr/search?string=586_CPU

I can't see anything that 586 have and that 686 lack.

[phoenix]

This page shows all the different copy functions configured when I586_CPU is enabled. There are no entries for I686_CPU in there, which tells me that all the optimisations are enabled for I585_CPU and not for I686_CPU. Haven't looked through any of the other pages in that list just yet.