Re: 2G P4M won't go above 1.2 - cpuinfo_max_freq too low

[Thomas Renninger <trenn@suse.de>]

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Simon wrote:

>Enabling the old interface in the kernel and doing a `echo -n 
>0%0%100%performance > /proc/cpufreq` doesn't change things either.
>
>Here is my /proc/cpuinfo
>model name      : Mobile Intel(R) Pentium(R) 4 - M CPU 2.00GHz
>cpu MHz         : 1198.976
>
>Any ideas how to get hold of my extra mhz?
>  
>
I have the same problem, cpuinfo shows the wrong value!!!
I get 1200MHz even I set it up to 1800MHz.
(posted prog calculates the right value, (procspeed))

My values:

cat scaling_setspeed
1800000

procspeed
1795.069753 MHz processor.

cat /proc/cpuinfo
cpu MHz : 1196.427

# HERE I SET NEW SPEED!
echo 1200000 >scaling_setspeed

procspeed
1196.468220 MHz processor.

# THIS IS TOTALLY WRONG!
cat /proc/cpuinfo
cpu MHz : 797.618

cat scaling_setspeed
1200000

It seems as if cpuinfo shows the wrong value by the factor 1.5.
(min_freq: 1200, max_freq: 1800)

kernel: 2.6.0test-11-1

I post a small prog you can mesure your real speed.
It's called procspeed(think it was part of Carl Thomson's cpufreqd).

I searched for cpuinfo in the archive, but could not find anything.
I expect that problem related to freq scaling ...

Does anyone know about this?

Maybe this helps, complete cpuinfo:

cat /proc/cpuinfo
processor : 0
vendor_id : GenuineIntel
cpu family : 15
model : 2
model name : Intel(R) Pentium(R) 4 Mobile CPU 1.80GHz
stepping : 4
cpu MHz : 1196.427
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 sep mtrr pge mca cmov pat 
pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm
bogomips : 2334.72


Thanks.

Thomas

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#include <stdio.h>
#include <sys/time.h>

__inline__ unsigned long long int rdtsc()
{
	unsigned long long int x;
	__asm__ volatile (".byte 0x0f, 0x31" : "=A" (x));
	return x;
}

main ()
{
	struct timezone tz;
        struct timeval tvstart, tvstop;
        unsigned long long int cycles[2]; /* gotta be 64 bit */
	unsigned int microseconds; /* total time taken */
	
	bzero(&tz, sizeof(tz));

	/* get this function in cached memory */
	gettimeofday(&tvstart, &tz);
	cycles[0] = rdtsc();
	gettimeofday(&tvstart, &tz);

	/* we don't trust that this is any specific length of time */
	sleep(1);
	
	cycles[1] = rdtsc();
	gettimeofday(&tvstop, &tz);
	microseconds = ((tvstop.tv_sec-tvstart.tv_sec)*1000000) +
		(tvstop.tv_usec-tvstart.tv_usec);

	printf("%f MHz processor.\n",
		(float)(cycles[1]-cycles[0])/microseconds);
}


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