Re: DAX mapping detection (was: Re: [PATCH] Fix region lost in /proc/self/smaps)
On Thu, Sep 08, 2016 at 04:56:36PM -0600, Ross Zwisler wrote:
I think this goes back to our previous discussion about support for
the PMEM
programming model. Really I think what NVML needs isn't a way to tell if it
is getting a DAX mapping, but whether it is getting a DAX mapping on a
filesystem that fully supports the PMEM programming model. This of course is
defined to be a filesystem where it can do all of its flushes from userspace
safely and never call fsync/msync, and that allocations that happen in page
faults will be synchronized to media before the page fault completes.
That's a an easy way to flag: you will never get that from a Linux
filesystem, period.
NVML folks really need to stop taking crack and dreaming this could
happen.