Hyperthreating

[niki]

Re: Hyperthreating

ok, removed the smp and all 686 - related files and did a reinstall of the 686-smp kernel incl the restricted modules and was able to boot !!!!
this is what my cpuinfo gave:

niki@Dell8300:~$ cat /proc/cpuinfo
processor       : 0
vendor_id       : GenuineIntel
cpu family      : 15
model           : 2
model name      : Intel(R) Pentium(R) 4 CPU 2.80GHz
stepping        : 9
cpu MHz         : 2793.392
cache size      : 512 KB
fdiv_bug        : no
hlt_bug         : no
f00f_bug        : no
coma_bug        : no
fpu             : yes
fpu_exception   : yes
cpuid level     : 2
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe cid xtpr
bogomips        : 5591.95

processor       : 1
vendor_id       : GenuineIntel
cpu family      : 15
model           : 2
model name      : Intel(R) Pentium(R) 4 CPU 2.80GHz
stepping        : 9
cpu MHz         : 2793.392
cache size      : 512 KB
fdiv_bug        : no
hlt_bug         : no
f00f_bug        : no
coma_bug        : no
fpu             : yes
fpu_exception   : yes
cpuid level     : 2
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe cid xtpr
bogomips        : 5586.48

niki@Dell8300:~$ uname -v
#1 SMP PREEMPT Sat Sep 16 02:13:27 UTC 2006
niki@Dell8300:~$ dmesg |grep CPU
[17179569.184000] Initializing CPU#0
[17179572.132000] CPU: After generic identify, caps: bfebfbff 00000000 00000000 00000000 00004400 00000000 00000000
[17179572.132000] CPU: After vendor identify, caps: bfebfbff 00000000 00000000 00000000 00004400 00000000 00000000
[17179572.132000] CPU: Trace cache: 12K uops, L1 D cache: 8K
[17179572.132000] CPU: L2 cache: 512K
[17179572.132000] CPU: Hyper-Threading is disabled
[17179572.132000] CPU: After all inits, caps: bfebfbff 00000000 00000000 00000080 00004400 00000000 00000000
[17179572.640000] CPU0: Intel(R) Pentium(R) 4 CPU 2.80GHz stepping 09
[17179572.652000] Initializing CPU#1
[17179572.732000] CPU: After generic identify, caps: bfebfbff 00000000 00000000 00000000 00004400 00000000 00000000
[17179572.732000] CPU: After vendor identify, caps: bfebfbff 00000000 00000000 00000000 00004400 00000000 00000000
[17179572.732000] CPU: Trace cache: 12K uops, L1 D cache: 8K
[17179572.732000] CPU: L2 cache: 512K
[17179572.732000] CPU: Hyper-Threading is disabled
[17179572.732000] CPU: After all inits, caps: bfebfbff 00000000 00000000 00000080 00004400 00000000 00000000
[17179572.732000] CPU1: Intel(R) Pentium(R) 4 CPU 2.80GHz stepping 09
[17179572.876000] checking TSC synchronization across 2 CPUs: passed.
[17179572.880000] Brought up 2 CPUs

So my single core cpu with HT shows up as 2 CPU's each with HT disabled!!
Guess this means that HT is actually working.

Now i'm afraid to reboot, big change that things wont work anymore in 686-smp :P

Here goes nothing

[sky]

Re: Hyperthreating

Hi,

It should work also, in fact, I think that the stock kernel is detecting also the hyperthreading...

Cheers

[zaflaucich]

Re: Hyperthreating

good!
and remember to add ht=on to the kernel option to really enable HT

[niki]

Re: Hyperthreating

Weird, weird, weird...

Now the smp-kernel boots up 1 out of 2 or 3 times. Before it just booted only the first time and then no more. I guess it has something to do with my hardware (Dell8300 pc). For now i cant say it hasn't improved, but it still isn't what i would like it to be (100% bootable vs 33%).
I'll stumble on with this ratio until a new ( and hopefully better) upgrade is available of the smp-kernel which will completely solve my problem.

thx guys (and girls?) for the support.
Hope i'll be able to return the favour some day...

niki

[niki]

Re: Hyperthreating

Well, i'm back to square one apparantly.
HT worked fine for one day or so after that .... no more HT , system each time reboots when i try to choose my 686-smp kernel from Grub.
When i do a full uninstall of the 686-smp kernel and a full reinstall it works fine for 2 or 3 times. After that i cant start up the 686-smp kernel anymore.
I guess it changes some sort of setting after which it wont startup anymore.

Anybody can give me a clue on what is going wrong

thx

[underdog5004]

Re: Hyperthreating

So, I was reading the thread and noticed that I've got a p4 @3.00Ghz that supports hyperthreading. So I downloaded the kernel through synaptic (along with all the dependencies) and rebooted. It worked perfectly. When I type

uname -v

I get

SMP PREEMPT

. Overall, I haven't really noticed any improvement in performance...but I don't really do anything intensive on it anyways. Thanks for the "how-to" (I guess).

-Matthew