Re: "Directly mapped persistent memory page cache"

[Jeff Moyer]

Ingo Molnar <mingo@xxxxxxxxxx> writes:

>> [...] support for atomicity (to avoid journaling in PM space), etc.
>
> This too should work fine, by way of the SMP coherency protocol, if 
> atomic instructions are used on the relevant metadata.

This isn't true.  Visibility and durability are two very different
things.  That's what pcommit is all about.  Search for it in this
document, if you aren't already familiar with it:
  https://software.intel.com/en-us/intel-architecture-instruction-set-extensions-programming-reference

However, in the context of your page structures that are re-initialized
every boot, durability doesn't matter.  So maybe that's what you were
saying?

Cheers,
Jeff
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