Re: [RFC 0/2] New MAP_PMEM_AWARE mmap flag
Jeff Moyer <jmoyer(a)redhat.com> writes:
> The big issue we have right now is that we haven't made the
DAX/pmem
> infrastructure work correctly and reliably for general use. Hence
> adding new APIs to workaround cases where we haven't yet provided
> correct behaviour, let alone optimised for performance is, quite
> frankly, a clear case premature optimisation.
Again, I see the two things as separate issues. You need both.
Implementing MAP_SYNC doesn't mean we don't have to solve the bigger
issue of making existing applications work safely.
I want to add one more thing to this discussion, just for the sake of
clarity. When I talk about existing applications and pmem, I mean
applications that already know how to detect and recover from torn
sectors. Any application that assumes hardware does not tear sectors
should be run on a file system layered on top of the btt.
I think this underlying assumption may have been overlooked in this
discussion, and could very well be a source of confusion.
Cheers,
Jeff