topic Re: Re:EPC allocation policy on multisocket machines - Intel(R) Xeon(R) Gold 6348 CPU @ 2.60GHz in Intel® Software Guard Extensions (Intel® SGX)

EPC allocation policy on multisocket machines - Intel(R) Xeon(R) Gold 6348 CPU @ 2.60GHz

boukhari — Fri, 04 Nov 2022 21:32:29 GMT

Hello,

I am writing an intel sgx application on a multisocket machine. I am running some benchmarks and I need to do numa aware allocation inside the enclave. Is there a way I can force the enclave to allocate EPC pages on a specific numa socket? If that's not possible, how can I check on which numa socket are the epc pages being allocated? Is there a default policy for allocation?

Cheers,

Yassine

Re:EPC allocation policy on multisocket machines - Intel(R) Xeon(R) Gold 6348 CPU @ 2.60GHz

Sahira_Intel — Wed, 09 Nov 2022 21:10:29 GMT

Hi,

If you are using Linux kernel 5.13 or newer with the SGX driver built in, it already has basic NUMA-aware allocation build in. This means that it will try to allocate all required EPC for a given enclave on a single CPU (so it won't span memory allocation across the sockets). You can read more about the patch here.

Sincerely,

Sahira

Re: Re:EPC allocation policy on multisocket machines - Intel(R) Xeon(R) Gold 6348 CPU @ 2.60GHz

boukhari — Wed, 09 Nov 2022 21:39:11 GMT

Hi,

Is there a way to force the enclave to do cross numa allocation? I need this feature to do some benchmarking regarding the memory access latencies in case of cross numa memory access ?

Re: EPC allocation policy on multisocket machines - Intel(R) Xeon(R) Gold 6348 CPU @ 2.60GHz

Sahira_Intel — Tue, 15 Nov 2022 18:00:22 GMT

Hi,

There is no out of box way to force the enclave to do cross numa allocation. You would need to modify the kernel driver in order to accomplish this.

Sincerely,

Sahira