how to turn off a cpu thread?

[vofsky]

Since one Itanium processor has four threads,Could I turn off the hyperthreading?

[Torsten.]

You can only **turn on** hyperthreading with hp-ux 11.31.

It is default off with 11.23.

Check with

# setboot

[Torsten.]

Example:

# setboot
...

Autoboot is ON (enabled)
Hyperthreading : OFF
: OFF (next boot)

To turn it off:

# setboot -m off
...

Hyperthreading : ON
: OFF (next boot)

==> reboot

(Note: It's always off in 11.23)

[Torsten.]

Example if you are on EFI shell:

Shell> cpuconfig

PROCESSOR MODULE INFORMATION

# of L3 L4 Family/
CPU Logical Cache Cache Model Processor
Module CPUs Speed Size Size (hex.) Rev State
------ ------- -------- ------ ------ ------- --- ------------
0 4 1.67 GHz 9 MB None 20/01 A1 Active
1 4 1.67 GHz 9 MB None 20/01 A1 Active

CPU threads are turned on.
CPU pstates are turned on.



Shell> cpuconfig threads

cpuconfig: CPU threads are turned on.

Shell> cpuconfig threads off

cpuconfig: CPU threads will be off after a reset.

[rick jones]

If I recall correctly, 11iv3 (11.31) has the ability to effectively enable/disable the threads on a processor set basis beyond the overall on vs off one can do with the likes of cpuconfig at EFI and stuff already shown with setboot.