Le 25/03/2019 à 17:56, Dan Williams a écrit : > > I'm generally against the concept that a "pmem" or "type" flag should > indicate anything about the expected performance of the address range. > The kernel should explicitly look to the HMAT for performance data and > not otherwise make type-based performance assumptions. Oh sorry, I didn't mean to have the kernel use such a flag to decide of placement, but rather to expose more information to userspace to clarify what all these nodes are about when userspace will decide where to allocate things. I understand that current NVDIMM-F are not slower than DDR and HMAT would better describe this than a flag. But I have seen so many buggy or dummy SLIT tables in the past that I wonder if we can expect HMAT to be widely available (and correct). Is there a safe fallback in case of missing or buggy HMAT? For instance, is DDR supposed to be listed before NVDIMM (or HBM) in SRAT? Brice
