Re: [PATCH 0/4] Allow persistent memory to be used like normal RAM

[Dan Williams]

On Thu, Jan 17, 2019 at 8:29 AM Jeff Moyer <jmoyer@xxxxxxxxxx> wrote:
>
> Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> writes:
>
> > Persistent memory is cool.  But, currently, you have to rewrite
> > your applications to use it.  Wouldn't it be cool if you could
> > just have it show up in your system like normal RAM and get to
> > it like a slow blob of memory?  Well... have I got the patch
> > series for you!
>
> So, isn't that what memory mode is for?
>   https://itpeernetwork.intel.com/intel-optane-dc-persistent-memory-operating-modes/

That's a hardware cache that privately manages DRAM in front of PMEM.
It benefits from some help from software [1].

> Why do we need this code in the kernel?

This goes further and enables software managed allocation decisions
with the full DRAM + PMEM address space.

[1]: https://lore.kernel.org/lkml/154767945660.1983228.12167020940431682725.stgit@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/