Eliot Moss wrote: > The configuration guidance for nvdimm indicates that fsdax mode requires 64 > byte of metadata per 4K bytes of nvdimm. The map= command line argument can > be used to control whether that metadata is stored in the nvdimm or regular > (presumably DRAM) memory. We were pondering this as wonder what the metadata > is used for. I am thinking someone on this list can clarify. Thanks!
sizeof(struct page) == 64 (in most cases) 'struct page' is the object that describes the state of physical memory pages to the rest of the kernel. Matthew wrote a useful summary of 'struct page' here: https://blogs.oracle.com/linux/post/struct-page-the-linux-physical-page-frame-data-structure > Eliot Moss > > PS: Concerning that huge pages mapping question from a while back, is there an > fsdax group / list to which I could post that for followup? Thanks - EM The 'fsdax' topic ties together [email protected], [email protected], and [email protected]. So it depends on what aspect you're digging into. When in doubt you can start here on [email protected] and folks here can help route. IIRC you had a question about storage allocation alignment and huge mappings? I forgot the details of the questionover the holiday break.
