topic Re: Hyperthreading gets disabled after every reboot in Operating System - HP-UX

Hyperthreading gets disabled after every reboot

Michael Streifel — Fri, 04 Dec 2020 17:20:38 GMT

Running HP-UX 11.31 on Itanium server rx2800

I have set threads on at the EFI prompt: cpuconfig threads on

setboot -v

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

And I have set the kctune lcpu_attr=1 from smh

kctune -q lcpu_attr
Tunable Value Expression Changes
lcpu_attr (now) 0 0 Imm (auto disabled)
(next boot) 1 1

Everytime that I reboot, the kctune returns the same value. That it currently is 0 but on the next boot it will be 1.

Here is the output of /stand

ls -l /stand
total 265792
-rw-r--r-- 1 root sys 0 Oct 14 12:03 .kc.lock
drwxr-xr-x 5 root sys 8192 Dec 3 15:56 backup
dr-xr-xr-x 3 bin bin 96 Oct 14 12:03 boot.sys
-rw-r--r-- 1 root sys 22 Oct 14 11:46 bootconf
lrwxr-xr-x 1 root root 14 Dec 3 17:21 bootfs -> current/bootfs
drwxr-xr-x 5 root sys 8192 Dec 3 15:52 current
-rw-r--r-- 1 root sys 12232 Dec 3 17:21 ext_ioconfig
-rw-r--r-- 1 root sys 12232 Dec 3 17:21 ext_ioconfig.lkg
-rw-r--r-- 1 root sys 7288 Dec 3 17:21 ioconfig
-rw-r--r-- 1 root sys 7288 Dec 3 17:21 ioconfig.lkg
drwxr-xr-x 2 root sys 96 Dec 3 17:22 krs
drwxr-xr-x 5 root sys 8192 Oct 14 13:38 last_install
drwxr-xr-x 5 root sys 8192 Dec 3 14:31 lcpu_change
drwxr-xr-x 2 root root 96 Oct 14 11:45 lost+found
drwxr-xr-x 5 root sys 8192 Dec 3 14:59 newbuild
lrwxr-xr-x 1 root root 7 Dec 3 17:21 nextboot -> current
-rw------- 1 root root 40 Dec 3 17:21 rootconf
lrwxr-xr-x 1 root root 15 Dec 3 17:21 system -> nextboot/system
-rw-r--r-- 1 root sys 4989 Nov 30 16:17 system.prev
-rwxr-xr-x 5 root sys 135967224 Nov 30 16:47 vmunix

Re: Hyperthreading gets disabled after every reboot

Duncan Edmonstone — Sat, 05 Dec 2020 16:17:46 GMT

Sounds like this: https://support.hpe.com/hpesc/public/docDisplay?docId=emr_na-c01066005

Have you tried "setboot -m on" ?

Re: Hyperthreading gets disabled after every reboot

Michael Streifel — Sat, 05 Dec 2020 16:24:58 GMT

Yes, and I still get the same results. It's like the next reboot kernel never gets put into place.

Re: Hyperthreading gets disabled after every reboot

Duncan Edmonstone — Sat, 05 Dec 2020 22:35:01 GMT

This server doesn't have the Integrity Virtual Machines software installed does it? I'm pretty sure that forces hyperthreading to be permanently off.

Re: Hyperthreading gets disabled after every reboot

Michael Streifel — Sun, 06 Dec 2020 01:21:34 GMT

No, it doesn't have Intergrity VM installed.

Re: Hyperthreading gets disabled after every reboot

Duncan Edmonstone — Sun, 06 Dec 2020 13:50:35 GMT

>> No, it doesn't have Intergrity VM installed.

Are you completely sure? You don't get anything from running:

# hpvminfo

Re: Hyperthreading gets disabled after every reboot

Michael Streifel — Mon, 07 Dec 2020 15:17:48 GMT

I get the following:

hpvminfo: Not on an HPVM guest, HPVM vPar or HPVM host.

Re: Hyperthreading gets disabled after every reboot

Duncan Edmonstone — Wed, 09 Dec 2020 07:46:04 GMT

which is good... I'm out of ideas - have you tried changing another kernel parameter that requires a reboot to change, just so you can confirm if this is a problem with kernel chnages in general or something specific to hyperthreading?

Re: Hyperthreading gets disabled after every reboot

Michael Streifel — Wed, 09 Dec 2020 16:24:50 GMT

I can change other kernel parameters without any problems. Appears to just be hyperthreading not getting changed.