RE: Proposal for Updating CRC32C with AVX-512 Algorithm.

> This is extremely workload dependent, it's not hard to find workloads with
> lots of very small record and very few big ones...  What you observed might
> have "just" been the warmup behaviour where more full page writes have to
> be written.

Can you tell me how to avoid capturing this "warm-up" so that the numbers are more accurate?

> There a very frequent call computing COMP_CRC32C over just 20 bytes, while
> holding a crucial lock.  If we were to do introduce something like this
> AVX-512 algorithm, it'd probably be worth to dispatch differently in case of
> compile-time known small lengths.

So are you suggesting that we be able to directly call into the 64/32 bit based algorithm directly from these known
smallbyte cases in the code? I think that we can do that with a separate API being exposed. 

> How does the latency of the AVX-512 algorithm compare to just using the
> CRC32C instruction?

I think I need more information on this one as I am not sure I understand the use case? The same function pointer
indirectmethods are used with or without the AVX-512 algorithm? 

Paul