CPU的电源管理是会影响性能的。
pstate指CPU忙时的电源管理，为了省电会调节主频和电压。cstate是cpu闲时的电压管理。
详细资料见：
https://software.intel.com/en-us/blogs/2008/05/29/what-exactly-is-a-p-state-pt-1
https://www.thomas-krenn.com/en/wiki/Processor_P-states_and_C-states
linux与kernel如何针对电源管理进行调度：
https://www.kernel.org/doc/html/v4.12/admin-guide/kernel-parameters.html
https://www.kernel.org/doc/html/v4.12/admin-guide/pm/cpufreq.html
https://www.kernel.org/doc/html/v4.12/admin-guide/pm/intel_pstate.html
最简单的，直接关掉它的方法：（见红字）
intel_pstate=disable intel_idle.max_cstate=0 processor.max_cstate=0
[root@tong ~]# cat /proc/cmdline BOOT_IMAGE=/vmlinuz-3.10.0-693.21.4.el7.x86_64 root=UUID=027f3098-783a-491a-9b1a-4d78a910952a ro crashkernel=auto isolcpus=1,4,6,17,20,22 intel_pstate=disable intel_idle.max_cstate=0 processor.max_cstate=0 rhgb quiet
原文：https://www.cnblogs.com/hugetong/p/12176618.html