LinuxQuestions.org - Processor frequency change

In my Linux system,I know on 100%,I can change processor frequency. If I provide to u-boot parameter of bootargs "mpurate=1000", the system starts working with frequency 1 GHz.But this is not,what I want. I need to change frequncy "on the fly".During the application is working. I found many information in Web,but all info is concentrated about /sys/devices/system/cpu/cpu#/cpufreq interface.So,changing frequency is done by: echo 1000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed
Or,I can add package cpufrequtils and has utilities :cpufreq-set,cpufreq-info and others,I do not need them.
So what really happens in my case,after: echo 1000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed or after cpufreq-set -f 1000MHz.
1.I do not get any error message,that means - everything is OK and operation completed successfully.
2.Modification time of /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed file changed after:
echo1000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed , that means everything is OK
and operation completed successfully.
3.cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed output me 800000(means 800МHz)like it was.
4.cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_cur_freq output me 800000(means 800МHz)like it was.
5.cat /proc/cpuinfo output me
Processor : ARMv7 Processor rev 2 (v7l)
BogoMIPS : 799.29
Features : swp half thumb fastmult vfp edsp neon vfpv3
CPU implementer : 0x41
CPU architecture: 7
CPU variant : 0x3
CPU part : 0xc08
CPU revision : 2
Hardware : IdentyTech IDT-SOM-OM3730
Revision : 0020
Serial : 0000000000000000

BogoMIPS : 799.29 means nothing changed.
6.cpufreq-info output me,frequency did not changed.

Somebody know,what is the problem?
Thank you.