In CHI, if HN sends one writenosnp with request order to SN, and sends readnosnp with request order and the same address to SN right after the DBIDResp of previous writenosnp, should SN process the readnosnp after the writenosnp finishes? or it doesn't need to.
The SN is required to order the WriteNoSnoop before the ReadNoSnoop in this case. From B2.6.5.1 in the CHI Specification
"– For requests that require Request Order, the Completer maintains order between requests to the same address from the same source."
Note, request order can only be set from a HN-I to an SN-I in the context of a HN -> SN request.