On Tue, Feb 23, 2016 at 3:28 PM, Jeff Moyer <jmoyer(a)redhat.com> wrote:
> The crux of the problem, in my opinion, is that we're asking
for an "I
> know what I'm doing" flag, and I expect that's an impossible statement
> for a filesystem to trust generically.
The file system already trusts that. If an application doesn't use
fsync properly, guess what, it will break. This line of reasoning
doesn't make any sense to me.
No, I'm worried about the case where an app specifies MAP_PMEM_AWARE
uses fsync correctly, and fails to flush cpu cache.
> If you can get MAP_PMEM_AWARE in, great, but I'm more and
more of the
> opinion that the "I know what I'm doing" interface should be something
> separate from today's trusted filesystems.
Just so I understand you, MAP_PMEM_AWARE isn't the "I know what I'm
doing" interface, right?
It is the "I know what I'm doing" interface, MAP_PMEM_AWARE asserts "I
know when to flush the cpu relative to an fsync()".