CPU 거버너가 최대 CPU 속도 제한을 준수하지 않는 이유는 무엇입니까?

나는 다음을 실행했다:

sudo parallel cpufreq-set -c {} -u 2000MHz ::: 0 1 2 3

그러나 CPU에 스트레스를 가하면 다음과 같이 cpufreq-info반환됩니다.

analyzing CPU 2:
  driver: intel_pstate
  CPUs which run at the same hardware frequency: 2
  CPUs which need to have their frequency coordinated by software: 2
  maximum transition latency: 4294.55 ms.
  hardware limits: 800 MHz - 2.90 GHz
  available cpufreq governors: performance, powersave
  current policy: frequency should be within 800 MHz and 2.00 GHz.
                  The governor "powersave" may decide which speed to use
                  within this range.
  current CPU frequency is 2.29 GHz.

2.29GHz는 2.00GHz보다 높습니다. 이 동작은 모든 코어에서 발생합니다.

주파수 제한을 완전히 무시하는 것과 같습니다.

왜 이런 일이 발생합니까? 이런 일이 발생하지 않도록 하는 방법이 있나요?

$ uname -a
Linux travel 4.15.0-72-generic #81-Ubuntu SMP Tue Nov 26 12:20:02 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux

$ cat /proc/cpuinfo
processor       : 3
vendor_id       : GenuineIntel
cpu family      : 6
model           : 42
model name      : Intel(R) Core(TM) i5-2410M CPU @ 2.30GHz
stepping        : 7
microcode       : 0x2f
cpu MHz         : 1792.712
cache size      : 3072 KB
physical id     : 0
siblings        : 4
core id         : 1
cpu cores       : 2
apicid          : 3
initial apicid  : 3
fpu             : yes
fpu_exception   : yes
cpuid level     : 13
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 syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts nopl xtopology nonstop_tsc cpuid aperfmperf pni pclmulqdq dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm pcid sse4_1 sse4_2 x2apic popcnt tsc_deadline_timer aes xsave avx lahf_lm epb pti ssbd ibrs ibpb stibp tpr_shadow vnmi flexpriority ept vpid xsaveopt dtherm ida arat pln pts md_clear flush_l1d
bugs            : cpu_meltdown spectre_v1 spectre_v2 spec_store_bypass l1tf mds swapgs itlb_multihit
bogomips        : 4585.01
clflush size    : 64
cache_alignment : 64
address sizes   : 36 bits physical, 48 bits virtual
power management: