Re: {Spam?} Re: [LARTC] HTB speed

[Jeroen Vriesman]

List,

I just logged in to a machine with a modern AMD cpu, it also has a TSC.

[EMAIL PROTECTED]:~> cat /proc/cpuinfo
processor   : 0
vendor_id   : AuthenticAMD
cpu family  : 6
model   : 6
model name  : AMD Athlon(TM) XP 2000+
stepping: 2
cpu MHz : 1668.736
cache size  : 256 KB
fdiv_bug: no
hlt_bug : no
f00f_bug: no
coma_bug: no
fpu : yes
fpu_exception   : yes
cpuid level : 1
wp  : yes
flags   : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat 
pse36 mmx fxsr sse syscall mmxext 3dnowext 3dnow
bogomips: 3329.22/^\
  |

So, I think you have to pull some managers' tie and demand new hardware :)

Jeroen.





On Mon, 15 Mar 2004 12:11:05 +
Maria Joana Urbano <[EMAIL PROTECTED]> wrote:

> 
> 
> Hi Jeroen,
> 
> Thanx for your fast answer.
> 
> 
> >to use the TSC, the processor has to have a tsc, you can see that in 
> >/proc/cpuinfo, for as far as I know, every P4 has it (but I'm not sure), 
> >it's in the "flags" of cpuinfo:
> >
> >On my P4-1800:
> >
> >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
> >
> >The "loop calibrated" jiffies stuff dates back to 386, it's used 
> >everywhere in the kernel timing, and it's very inaccurate, I don't know if 
> >2.6 still uses it everwhere, what kind of processor do you have?
> 
> I am using and old test machine with an AMD-K7 processor. I think that's 
> the reason I cannot use TSC, it only works in Pentium processors.
> 
> 
> >I've never tried to change the Hz value, does changing it in param.h 
> >really changes the frequency of the clock ticks? If so, why is the default 
> >only 100Hz these days? doesn't make sense to me.
> 
> I have no ideia why it is still at 100Hz. However, I took this clue from [1].
> 
> >I do use the PSCHED_CPU in a production environement at the moment, works 
> >fine.
> 
> OK, that's good news :-)
> 
> Regards,
> Joana
> 
> 
> [1] K. Wagner, "Short Evaluation of Linux's Token-Bucket-Filter (TBF) 
> Queuing Discipline"
> 
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Re: {Spam?} Re: [LARTC] HTB speed

[Maria Joana Urbano]

Hi Jeroen,

Thanx for your fast answer.


to use the TSC, the processor has to have a tsc, you can see that in 
/proc/cpuinfo, for as far as I know, every P4 has it (but I'm not sure), 
it's in the "flags" of cpuinfo:

On my P4-1800:

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

The "loop calibrated" jiffies stuff dates back to 386, it's used 
everywhere in the kernel timing, and it's very inaccurate, I don't know if 
2.6 still uses it everwhere, what kind of processor do you have?
I am using and old test machine with an AMD-K7 processor. I think that's 
the reason I cannot use TSC, it only works in Pentium processors.


I've never tried to change the Hz value, does changing it in param.h 
really changes the frequency of the clock ticks? If so, why is the default 
only 100Hz these days? doesn't make sense to me.
I have no ideia why it is still at 100Hz. However, I took this clue from [1].

I do use the PSCHED_CPU in a production environement at the moment, works 
fine.
OK, that's good news :-)

Regards,
Joana
[1] K. Wagner, "Short Evaluation of Linux's Token-Bucket-Filter (TBF) 
Queuing Discipline"

Re: {Spam?} Re: [LARTC] HTB speed

[Maria Joana Urbano]

Indeed, changing the timer to 1000Hz is possible, it turned out that I 
have a machine here running with a 1000Hz timer ticker. (I've installed a 
"realtime" kernel on it for audio recording).

About your previous question, I've noticed that the system with 1000Hz 
ticker (which has been running for a few months) is UNSTABLE.

might be more to it than just the 1000Hz, but I did notice that some 
"realtime" applications running in userspace where able to crash the 
system completely, happened 2 times in 3 months.

Hi Jeroen and all,

Does anybody else related the same problems of unstabilitty changing the 
timer to 1000Hz?

Thanks in advance,
Joana