On Wed, Jun 23, 2021 at 03:19:11PM +0800, Coly Li wrote: > Bcache does not support endian clean indeed, Then we need to fix that eventually rather than making it worse. Which means any _new_ data structure should start that way. > and libnvdimm only works with > 64bit physical address width. Maybe it does right now. But ther is nothing fundamental in that, so please don't design stupid on-disk formats to encode that are going to come back to bite us sooner or later. Be that by adding 32-bit support for any Linux DAX device, or by new 96 or 128bit CPUs. > The only restriction here by using pointer is > the CPU register word should be 64bits, because we use the NVDIMM as memory. > > Is it one of the way how NVDIMM (especially Intel AEP) designed to use ? > As a non-volatiled memory. Not for on-disk data structures. > Does the already mapped DAX base address change in runtime during memory > hot plugable ? > If not, it won't be a problem here for this specific use case. It could change between one use and another.