AMD64 X2 - kernel config advice ?

Message

drbenway · Post by **drbenway** » Thu Sep 27, 2007 8:54 pm

Hi.

I would like to know which of these options I need in my kernel.

I have a AMD64 X2 4600 (dual core) CPU

- SMT (Hyperthreading) scheduler support
- Multi-core scheduler support
- SMT (Hyperthreading) scheduler support

- Non Uniform Memory Access (NUMA) Support
- Old style AMD Opteron NUMA detection
- ACPI NUMA detection
- NUMA emulation

- IBM Calgary IOMMU support

Any advice will be welcomed, I have searched the forum but the info from different sources (and possibly times) gives conflicting advice.

pietia · Post by **pietia** » Thu Sep 27, 2007 9:18 pm

hi!

If you like - you can extend my kernel config for Asus A6TC laptop (turion64x2).
config for 64-bit multilib gentoo.

it's here -> http://asusa6tc.ovh.org/config-2.6.22-gentoo-r5

loftwyr · Post by **loftwyr** » Fri Sep 28, 2007 12:37 am

I have a 4800 X2 and this is what I've learned so far

- SMT (Hyperthreading) scheduler support -- No, only Intel has HT in their CPUs. AMD uses HyperTransport which is a different thing.
- Multi-core scheduler support -- Yes, you have a multicore CPU

- NUMA (etc.) -- You can but it won't make a difference as only Opterons support it

- IBM Calgary -- No, that's for a very specific type of processor.

Hope that helps.

pietia · Post by **pietia** » Fri Sep 28, 2007 8:36 am

loftwyr wrote: - SMT (Hyperthreading) scheduler support -- No, only Intel has HT in their CPUs. AMD uses HyperTransport which is a different thing.

Does including it in config cause any problems ?

drbenway · Post by **drbenway** » Fri Sep 28, 2007 11:00 am

Thanks for all the helpful advice.

I did use to know which optimum setting to use for my old athlon-xp, thank you for clearing up what i need for the AMD X2.

Btw - i have just tried the new backported CFS - http://kerneltrap.org/Linux/CFS_Develop ... Backported

My system now feels more responsive that the CK patchset.

Thanks,

loftwyr · Post by **loftwyr** » Fri Sep 28, 2007 5:35 pm

pietia wrote:
loftwyr wrote: - SMT (Hyperthreading) scheduler support -- No, only Intel has HT in their CPUs. AMD uses HyperTransport which is a different thing.
Does including it in config cause any problems ?

Nope it will be ignored by the kernel when it sees a non-Intel chip.

drbenway · Post by **drbenway** » Sun Sep 30, 2007 11:56 am

Hi.

One last option I am unsure to use or not is

Cpuset support.

Should I enable this or not ?

I so far assume that I do not use it.

Any advice is welcomed.

Thanks.

Keruskerfuerst · Post by **Keruskerfuerst** » Mon Oct 01, 2007 10:59 am

Where can I find CPU set support?

drbenway · Post by **drbenway** » Mon Oct 01, 2007 1:14 pm

Hi - i make menuconfig it is

General setup --->
[ ] Cpuset support

It says :---
------------------------

CONFIG_CPUSETS: │
│ │
│ This option will let you create and manage CPUSETs which │
│ allow dynamically partitioning a system into sets of CPUs and │
│ Memory Nodes and assigning tasks to run only within those sets. │
│ This is primarily useful on large SMP or NUMA systems. │
│ │
│ Say N if unsure.
------------------------

I am using 2.6.22-r8 (gentoo) kernel compiled for amd64

My reasoning for not enabling this feature is it says 'large SMP or NUMA systems' - I just have an AMD64 X2 CPU.

Anyone know if I should enable/disable this feature ?

pussi · Post by **pussi** » Mon Oct 01, 2007 1:44 pm

Say N if unsure.

you won't be needing it.

hvengel · Post by **hvengel** » Tue Oct 09, 2007 7:51 pm

At least with older kernels I found that NUMA = yes caused problems when running the nvidia proprietary drivers. It is only useful if you have a multi-processor system AND each processor has it own memory bus. Definitely not something that is useful for an X2.