On 6/23/21 3:04 PM, Christoph Hellwig wrote: > Storing a pointer on-media is completely broken. It is not endian > clean, not 32-bit vs 64-bit clean and will lead to problems when addresses Why it is not endian clean, and not 32-bit vs. 64 bit clean for bcache ? Bcache does not support endian clean indeed, and libnvdimm only works with 64bit physical address width. 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. > change. And they will change - maybe not often with DDR-attached > memory, but very certainly with CXL-attached memory that is completely > hot pluggable. 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. Coly Li