What is the typical cache size of MMU paging-structures?

[vny]

Typical TLB sizes are well known for different page sizes (4KB, 2MiB, etc) however there is very little known about the page table cache sizes (E.g. Paging-Structure Caches from Sec 4.10.3 Vol 3A of the Intel Software Developer Manual). In addition to the TLB and PDE, a processor may cache partial page walks in memory. Either per level cache size (intel) or the unified page table cache size (amd). I skimmed through Intel's Software Developer Manual Vol 3 Chapter 4 and could not find answers for any of the following questions.

I am interested in knowing the following for a real microarchitecture (E.g. Skylake):

1. What is the typical cache size?
2. Are the cache sizes same across levels? How are they partitioned?
3. Does the number of entries per cache level change with the page granularity (4 KiB, 2 MiB)
4. Finally, what is the caching policy used? LRU?

[ACarmona_Intel]

Hello Vny,

Thank you for posting in our communities.

Before we can provide you with an appropriate answer, we wanted to confirm if the processor or product that you wanted to know regarding cache information is particularly about the XEON processor.

If yes, we have a different team handling it, and they will be the ones to provide you with appropriate answers.

Thank you, and have a great day ahead!

Best regards,

Carmona A.

Intel Customer Support Technician

[vny]

Hi Carmona, yes I am interested in Xeon. 
I have Xeon Gold 5218 2nd Gen and Xeon Gold 5218R.

Thanks!

[ACarmona_Intel]

Hello Vny,

Thank you so much for the response.

We have a forum category for specific issues related to your product, which is the XEON processors. This category is monitored by our experts, who can provide you with the appropriate answer. To help you get your answer more quickly, we will now move your post to that category.

Thank you, and have a great day ahead!

Best regards,

Carmona A.

Intel Customer Support Technician

[Azeem_Intel]

Hi vny,

Greetings for the day!

Hope you're doing well. Could you please confirm if you're seeking a comparison between the two processors, the Xeon Gold 5218 2nd Gen and the Xeon Gold 5218R? If not, could you please provide further details regarding your query so that we can assist you more effectively?

Please do not hesitate in contact us, we are more than glad to assist you.

Best Regards,

Azeem_Intel

[vny]

Not necessarily a comparison. I would like to know the exact cache sizes per PTE level. Thanks!

[vny]

Not necessarily a comparison. I would like to know the exact cache sizes per PTE level. Thanks!

[Azeem_Intel]

Hi vny,

Greetings for the day!

Sorry for the inconveniences. Could you please specify which processor details you require?

Please do not hesitate in contact us, we are more than glad to assist you.

Best Regards,

Azeem_Intel

[vny]

Xeon Gold 5218 2nd Gen and Xeon Gold 5218R

[Azeem_Intel]

Hi vny,

Greetings for the day!

Please find the link below.

Intel Xeon Gold 5218 Processor 22M Cache 2.30 GHz Product Specifications

Intel® Xeon® Gold 5218R Processor

Best Regards,

Azeem_Intel

[vny]

@Azeem_Intel  This does not have the information I am seeking. 

[Azeem_Intel]

Hi vny,

Greetings for the day!

Thank you for your response. Please allow us some time to investigate, and we will get back to you with a resolution shortly.

Please do not hesitate in contact us, we are more than glad to assist you.

Best Regards,

Azeem_Intel

[Azeem_Intel]

Hi vny,

Greetings for the day!

We appreciate your patience. Could you please let us know if you are developing software?

Please do not hesitate in contact us, we are more than glad to assist you.

Best Regards,

Azeem_Intel

[vny]

Yes I am. Knowing the page table cache sizes will be helpful.

[Azeem_Intel]

Hi vny,

Greetings for the day!

We request that you post your query to our software developer team. Our support team cannot assist with this matter. You need to submit a question through our software developer team using the following link:  https://community.intel.com/t5/Developer-Software-Forums/ct-p/developer-software-forums. However, we can provide all the available information in the Software Manuals, which can be accessed via this link: https://www.intel.com/content/www/us/en/developer/articles/technical/intel-sdm.html.

Best Regards,

Azeem_Intel