FreeBSD contigfree takes too much time on Xeon Gold 5115 CPU

[SRodr8]

Hi Folks,

I am seeing a FreeBSD 11.x OS poor performance issue on Xeon Gold CPU.

CPU is Intel(R) Xeon(R) Gold 5115 CPU @ 2.40GHz ( dual socket CPU with 10 cores per socket )

I have attached a simple kernel module program ( for FreeBSD) and its Makefile.

This just allocates 32KB contiguous memory using contigmalloc and then frees it using contigfree.

This repeated 1000 times and time taken by contigmalloc and contigfree is computed .

I can see that contigfree takes way too much time .

I have another older server running FreeBSD 11.2 Intel(R) Xeon(R) CPU E5-2620 v2 @ 2.10GHz (dual socket 6 core per socket

and in this I do not see such an issue .

Any idea why contigfree takes so much time on FreeBSD 11.x running on Xeon Gold 5115 CPU ?

Regards,

Steevan

[idata]

Hello Steev,

Please help us by providing more additional information:Can you please provide us with the model of your server board?Additionally, have you try to contact the operating system manufacturer and check if they have tested the Intel Xeon Gold processors?Best regards,Sergio S.

[SRodr8]

Thank you for the reply.

More details on System and CPU are given below

----------------------------------------------------------

dmesg | grep CPU

CPU: Intel(R) Xeon(R) Gold 5115 CPU @ 2.40GHz (2400.07-MHz K8-class CPU)

FreeBSD/SMP: Multiprocessor System Detected: 40 CPUs

System Information

Manufacturer: Supermicro

Product Name: Super Server

Version: 0123456789

Base Board Information

Manufacturer: Supermicro

Product Name: X11DPH-Tq

Version: 1.01

--------------------------------------------------------

Yes I even wrote to FreeBSD mailing lists and hacker groups and I got some responses.

Contigmalloc is known to be little expensive. But did not get any details about why contigfree takes so much time.

I am seeing another issue on this server ( again with FreeBSD) . The issue is, it takes too much time to create threads on this.

Please see these following links and look for "Create Threads" row.

https://openbenchmarking.org/result/1804094-AR-1804096AR58 https://openbenchmarking.org/result/1804094-AR-1804096AR58https://openbenchmarking.org/result/1807114-RA-WINDOWSSE47 https://openbenchmarking.org/result/1807114-RA-WINDOWSSE47

I feel this particular processor shows up some issues with FreeBSD OR FreeBSD OS has some issues when used with this processor.

Hence I am trying to check with folks at both Intel and FreeBSD developers.

Regards

Steevan

[idata]

Hello Steevan,

Please keep us posted with the findings from the developer of the operating systemBest regards,Sergio S.

[idata]

Hello Steevan,

I am following up your question and we would like to know if you were able to get in touch with the operating system developer. Best regards, Sergio S.

[SRodr8]

Hi Sergio,

I tried FreeBSD 12 Beta 3 version on this server with Xeon Gold 5115 CPU.

All these problems have disappeared. In this version also contigfree takes much more time compared to contigmalloc.

However when I compare the values to FreeBSD 11.x number I can see huge improvement in FreeBSD 12 Beta 3.

Hence it looks like the problem is with FreeBSD 11.x.

I am still waiting for final release version of FreeBSD 12.0

Regards,

Steevan

[idata]

Hello Steevan,

We are glad to hear that you were able to resolve your problem. Please feel free to contact us back in case you need further assistance.Best regards,Sergio S.Intel Customer Support TechnicianUnder Contract to Intel Corporation