"Aneesh Kumar K.V" <aneesh.ku...@linux.ibm.com> writes: > On 6/14/19 10:06 PM, Dan Williams wrote: >> On Fri, Jun 14, 2019 at 9:26 AM Aneesh Kumar K.V >> <aneesh.ku...@linux.ibm.com> wrote: > >>> Why not let the arch >>> arch decide the SUBSECTION_SHIFT and default to one subsection per >>> section if arch is not enabled to work with subsection. >> >> Because that keeps the implementation from ever reaching a point where >> a namespace might be able to be moved from one arch to another. If we >> can squash these arch differences then we can have a common tool to >> initialize namespaces outside of the kernel. The one wrinkle is >> device-dax that wants to enforce the mapping size, > > The fsdax have a much bigger issue right? The file system block size > is the same as PAGE_SIZE and we can't make it portable across archs > that support different PAGE_SIZE?
File system blocks are not tied to page size. They can't be *bigger* than the page size currently, but they can be smaller. Still, I don't see that as an arugment against trying to make the namespaces work across architectures. Consider a user who only has sector mode namespaces. We'd like that to work if at all possible. -Jeff
