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From:   Feng Li <lifeng1519@gmail.com>
Date:   Wed, 20 May 2020 14:47:54 +0800
Message-ID: <CAEK8JBDgHwX+kMA+Uo0=Ma4OPz65-cb-P5wCu1cPxo7cFRD-GQ@mail.gmail.com>
Subject: [ISSUE] acpi_cpufreq is added and removed frequently
To:     linux-kernel <linux-kernel@vger.kernel.org>
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Sender: linux-kernel-owner@vger.kernel.org
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Hi expert,

I could see my CentOS7,  `udevadm monitor` reports this log very fast:

UDEV  [14258.464055] change
/devices/LNXSYSTM:00/device:00/ACPI0004:01/LNXCPU:4d (acpi)
KERNEL[14258.464065] add      /module/acpi_cpufreq (module)
KERNEL[14258.471130] remove   /module/acpi_cpufreq (module)
UDEV  [14258.473672] change
/devices/LNXSYSTM:00/device:00/ACPI0004:01/LNXCPU:4a (acpi)
KERNEL[14258.473684] add      /module/acpi_cpufreq (module)
KERNEL[14258.482001] remove   /module/acpi_cpufreq (module)
UDEV  [14258.485059] change
/devices/LNXSYSTM:00/device:00/ACPI0004:01/LNXCPU:4f (acpi)
KERNEL[14258.485070] add      /module/acpi_cpufreq (module)
KERNEL[14258.495195] remove   /module/acpi_cpufreq (module)


What's wrong with the system?

OS: CentOS 7.6
Kernel: 3.10.0-1062.1.2.el7 / kernel-4.18.0-147

[root@67_95 14:46:21 ~]$lscpu
Architecture:          x86_64
CPU op-mode(s):        32-bit, 64-bit
Byte Order:            Little Endian
CPU(s):                16
On-line CPU(s) list:   0-15
Thread(s) per core:    2
Core(s) per socket:    4
Socket(s):             2
NUMA node(s):          2
Vendor ID:             GenuineIntel
CPU family:            6
Model:                 85
Model name:            Intel(R) Xeon(R) Gold 5122 CPU @ 3.60GHz
Stepping:              4
CPU MHz:               3677.124
CPU max MHz:           3700.0000
CPU min MHz:           1200.0000
BogoMIPS:              7200.00
Virtualization:        VT-x
L1d cache:             32K
L1i cache:             32K
L2 cache:              1024K
L3 cache:              16896K
NUMA node0 CPU(s):     0,2,4,6,8,10,12,14
NUMA node1 CPU(s):     1,3,5,7,9,11,13,15
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 pdpe1gb rdtscp lm constant_tsc art arch_perfmon pebs
bts rep_good nopl xtopology nonstop_tsc aperfmperf eagerfpu pni
pclmulqdq dtes64 monitor ds_cpl vmx smx est tm2 ssse3 sdbg fma cx16
xtpr pdcm pcid dca sse4_1 sse4_2 x2apic movbe popcnt
tsc_deadline_timer aes xsave avx f16c rdrand lahf_lm abm 3dnowprefetch
epb cat_l3 cdp_l3 invpcid_single intel_ppin intel_pt ssbd mba ibrs
ibpb stibp tpr_shadow vnmi flexpriority ept vpid fsgsbase tsc_adjust
bmi1 hle avx2 smep bmi2 erms invpcid rtm cqm mpx rdt_a avx512f
avx512dq rdseed adx smap clflushopt clwb avx512cd avx512bw avx512vl
xsaveopt xsavec xgetbv1 cqm_llc cqm_occup_llc cqm_mbm_total
cqm_mbm_local dtherm ida arat pln pts pku ospke spec_ctrl intel_stibp
flush_l1d

Any tips?
Thanks in advance.