About the kernel configuration(CONFIG_CPU_FREQ and CONFIG_CPU_IDLE.)
Hi, list I am using Linux 5.4.78 with PREEMPT_RT patch. Hardware name: UNO-2372G-J021AE. It's strange that the frequency of the CPU is not constant(i.e. not fixed at a specific frequency) if I both disable CONFIG_CPU_FREQ and CONFIG_CPU_IDLE whereas the frequency of the CPU is constant if I only disable CONFIG_CPU_FREQ (leave CONFIG_CPU_IDLE enabled). Could somebody please shed some light on this matter?
Updated: I check the frequency of the CPU by `cat /proc/cpuinfo`. On Wed, Jan 19, 2022 at 9:23 AM 孙世龙 sunshilong <sunshilong369@gmail.com> wrote:
Hi, list I am using Linux 5.4.78 with PREEMPT_RT patch. Hardware name: UNO-2372G-J021AE.
It's strange that the frequency of the CPU is not constant(i.e. not fixed at a specific frequency) if I both disable CONFIG_CPU_FREQ and CONFIG_CPU_IDLE whereas the frequency of the CPU is constant if I only disable CONFIG_CPU_FREQ (leave CONFIG_CPU_IDLE enabled).
Could somebody please shed some light on this matter?
On Tue, Jan 18, 2022 at 6:23 PM 孙世龙 sunshilong <sunshilong369@gmail.com> wrote:
Hi, list I am using Linux 5.4.78 with PREEMPT_RT patch. Hardware name: UNO-2372G-J021AE.
It's strange that the frequency of the CPU is not constant(i.e. not fixed at a specific frequency) if I both disable CONFIG_CPU_FREQ and CONFIG_CPU_IDLE whereas the frequency of the CPU is constant if I only disable CONFIG_CPU_FREQ (leave CONFIG_CPU_IDLE enabled).
Could somebody please shed some light on this matter?
just a WAG, but lower power draw has been hugely important for years, nobody would sacrifice that for "simplicity", such a feature would be unused. I could imagine enterprise SMM bios disallowing such operation. On dozens of processors over time, TSC has been marked unstable by the kernel, Id suppose that signals a certain distrust of some clocks.
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jim.cromie＠gmail.com -
孙世龙 sunshilong