Snipped > > > > Does the API need to be prepared for L4 cache? > > > https://www.anandtech.com/show/16924/did-ibm-just-preview-the-future > > > - > > of-caches > > Thank you for the pointer, yes initial patch was considering L4 cache > > too. But I was not able to get hold of system or get someone to test > > this with L4. > > Hence removed the L4 instance from dpdk_topology structure. > > > > We can introduce into v4. Can we get someone from IBM to confirm the > > same? > > If any of the CPU folks think L4 cache might become relevant in the > foreseeable > future, it should be added to the API without testing at this time.
I remember 3 L4 cache scenario 1. from IBM power-9 variant suggested in 2020-2021 in hot chips 2. from Intel a. Haswell|Broadwell series with eDram as L4 b. future product (at least in desktop) with L4 cache. > Adding it now would prevent API breakage whenever L4 cache actually becomes > relevant. > Otherwise please don't support for it - considering it would be dead and > untested > code. I can add the same to the DPDK topology probe in v4, on AMD EPYC v-cache is treated as extended L3 and not L4. Hence will not be able to test on AMD EPYC. > > > > > > > > > And - just a thought: > > > Since this library and the Cache Stashing (PCIe TLP) library are > > somewhat related, > > > would it be beneficial to combine them into one patch series, > > primarily to make their > > > APIs more uniform? > > > > There was initial zoom invite for understanding and usage, we expected > > a follow up on the same to close the loop. > > Based on my current understanding, the API to be used as hints to PMD > > should be passing `lcore id` only. > > Hence these can be independent. > > The Cache Stashing hints API uses a more specific destination than just > "lcore id". > The implementations of this Topology library and the Cache Stashing library > may be > completely independent, but the structure describing a location in the > topology could > be common. Thank you, now I understand, > > Maybe I should say this differently: > Wathsala and other folks working on the Cache Stashing API, you need to keep a > close eye on this Topology patch series! > We might expect the Cache Stashing API to reuse relevant structures from it.
