Huge page random access writes are slow

[MaximEgorushkin]

Huge pages seem to be broken on at least Coffee Lake and Skylake. Random access writes to 2MiB and 1GiB huge pages are 2x slower than those to 4KiB.

For full details see https://stackoverflow.com/q/63705244/412080

[Alberto_Sykes]

MaximEgorushkin, Thank you for posting in the Intel® Communities Support.

In reference to your inquiry, in order for us to be able to provide the most accurate assistance, we just wanted to check a few details about this matter:

Are you pointing to the Intel® Coffee Lake and Skylake Processors in general or you are referring to some specific models? If that is the case please provide those models.

Are you developing an application? 

Are you working on a project?

If so, could you please provide a description of what is that application/project about?

Any questions, please let me know.

Regards,

Albert R.

Intel Customer Support Technician

A Contingent Worker at Intel

[MaximEgorushkin]

Hi Albert,

The link in my original message provides you with all the details. But I don't mind repeating them here:

1. It seems that different processor models are affected, I only tested on i9-9900KS on Ubuntu 18.04.5, and it is affected. The original post mentions another model, I refer you there.

2. I do develop applications.

3. I do work on a project.

4. I work on projects in high frequency low latency trading, huge pages performance is quite important to me.

Again, the link provides code to replicate the problem with huge pages being slower for random access writes than 4KiB pages. That should never be the case and shows that something is not right with huge page performance.

[Alberto_Sykes]

Hello MaximEgorushkin, Thank you very much for providing that information.

In reference to this scenario, in this case, the best thing to do will be to visit, sign-in and submit your inquiry in our Intel® Developer Zone, where you will receive further peer to peer assistance on this topic:

https://software.intel.com/content/www/us/en/develop/home.html

Regards,

Albert R.

Intel Customer Support Technician

A Contingent Worker at Intel