Experimental Features Feedback Forum

ID 672801
Updated 7/6/2021
Version Latest



We have an experimental feature to speedup TLB shootdowns that is available only in future Intel processors based on the Sapphire Rapids microarchitecture. We are seeking feedback from the community that finds this interesting enough to try using it.  This article introduces the feature, has a link to the detailed whitepaper, and has information on how to provide feedback.

Experimental Features via Model Specific capabilities

Occasionally we add special features in our products in order to get full ecosystem feedback, based on usage in production systems, before we decide on the future for such features.  Because these features may not exist in the future, or may change substantially based on feedback, we specify these as 'model-specific features.' Any code using such a feature, needs to use Family and Model information (obtained via CPUID) to determine if the feature is available (details in the whitepaper).

Remote Action Request (RAR) based TLB Shootdowns

Software vs RAR TLB shootdownsCurrently, we have a feature for remote action request (RAR) based TLB shootdowns. This feature is available only in Intel processors based on the Sapphire Rapid microarchitecture (CPUID Signature DisplayFamily_DisplayModel value of 06_8FH). Its possible inclusion in future processors will depend upon the feedback we receive.

Remote Action Request (RAR) is a feature to speed up inter-processor operations by moving parts of those operations from software (operating systems and/or applications) to hardware (the processor cores). This should speed up remote TLB shootdowns by allowing them to be serviced while a long instruction is executing on the remote processor or when interrupts are disabled on that processor.

RAR White Paper; Feedback Welcome

If this of interest to you, we encourage you to download and read our white paper "Remote Action Request."

We are interested in thoughtful feedback on our Experimental Features, which you can provide as comments to my posting in the community forum.  We will read your feedback, and reply to comments and questions.

Remote Action Request Whitepaper