Centos75 kernel-3.10.0-862 impact CPU max MHz on Intel E5-2620v4

Issues related to hardware problems
jizh
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Re: Centos75 kernel-3.10.0-862 impact CPU max MHz on Intel E5-2620v4

Post by jizh » 2019/01/02 05:28:39

We have proxysql process running on servers, and recommended with the network-latency profile,

jizh
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Joined: 2018/12/26 06:27:45

Re: Centos75 kernel-3.10.0-862 impact CPU max MHz on Intel E5-2620v4

Post by jizh » 2019/01/04 08:22:18

Is there a official announcement about centos7_5/7_6 changing the CPU Mhz and busy_poll ?
Thanks.

kazianwar
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Re: Centos75 kernel-3.10.0-862 impact CPU max MHz on Intel E5-2620v4

Post by kazianwar » 2020/08/03 15:50:40

Is there any resolution to this post? We are also seeing cpu frequency degradation in 3.10.0-862.el7(centos 7.5) and 3.10.0-957.1.3.el7(centos 7.6). 3.10.0-693.el7 (centos 7.4) worked as expected and showed the max frequency for all cores. We used the same hardware with turbo enabled in bios and same kernel parameters for each kernel. tuned setting was balanced every time. There much be some changes since 3.10.0-862.el7 that broke this.

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TrevorH
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Re: Centos75 kernel-3.10.0-862 impact CPU max MHz on Intel E5-2620v4

Post by TrevorH » 2020/08/03 16:07:24

Since none of those kernels are current ones, the question needs to be updated for 2020 and 7.8 which uses a 3.10.0-1127.18.2.el7 kernel at the current time. Only the current version of CentOS gets any support or attention. Running seriously backlevel versions will just result in the "upgrade and retest" answer.

I'd also question whether you are seeing the results of the innumerable Intel "oh we found another hardware security problem" fun and games that's been going on now for 2.5 years. Did you try booting with mitigations=off to test that theory?
The future appears to be RHEL or Debian. I think I'm going Debian.
Info for USB installs on http://wiki.centos.org/HowTos/InstallFromUSBkey
CentOS 5 and 6 are deadest, do not use them.
Use the FAQ Luke

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TrevorH
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Re: Centos75 kernel-3.10.0-862 impact CPU max MHz on Intel E5-2620v4

Post by TrevorH » 2020/08/03 16:20:28

I've just checked 2 systems, one using a pair of Intel E5-2650-v4 processors, 2.2GHz with up to 2.9GHz single core turbo and all core turbo of 2.5GHz and the other using a pair of Intel Gold 5118 2.3GHz processors with a single core turbo of 3.2GHz and an all core turbo of 2.7GHz and both show cores running at up to the all core turbo speed. So the e5-2650v4 shows all 24 cores running at 2.5GHz +/- 50MHz and the Gold 5118 shows the majority of the 24 cores running at 2.7GHz with a few running at lower frequencies though I believe that's due to lack of demand not lack of capability.

Both are using recent 7.8 kernels.
The future appears to be RHEL or Debian. I think I'm going Debian.
Info for USB installs on http://wiki.centos.org/HowTos/InstallFromUSBkey
CentOS 5 and 6 are deadest, do not use them.
Use the FAQ Luke

kazianwar
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Re: Centos75 kernel-3.10.0-862 impact CPU max MHz on Intel E5-2620v4

Post by kazianwar » 2020/08/03 17:57:13

TrevorH wrote:
2020/08/03 16:07:24
Since none of those kernels are current ones, the question needs to be updated for 2020 and 7.8 which uses a 3.10.0-1127.18.2.el7 kernel at the current time. Only the current version of CentOS gets any support or attention. Running seriously backlevel versions will just result in the "upgrade and retest" answer.

I'd also question whether you are seeing the results of the innumerable Intel "oh we found another hardware security problem" fun and games that's been going on now for 2.5 years. Did you try booting with mitigations=off to test that theory?
mitigations=off did'nt help. Also had spectre_v2=off etc parameters set. went through the bios settings as well. migrating to 7.8 from current 7.6 will require some effort. was hoping to nail down what changed between 7.4 and 7.5 to warrant this behavior.

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