If so, I wonder if we could instead do that comparison modulo the access/dirty
bits,
I think that would work - but will need to think a bit more on it.
and leave ptep_get_lockless() only reading a single entry?
I think we will need to do something a bit less fragile. ptep_get() does collect
the access/dirty bits so its confusing if ptep_get_lockless() doesn't IMHO. So
we will likely want to rename the function and make its documentation explicit
that it does not return those bits.
ptep_get_lockless_noyoungdirty()? yuk... Any ideas?
Of course if I could convince you the current implementation is safe, I might be
able to sidestep this optimization until a later date?
As discussed (and pointed out abive), there might be quite some
callsites where we don't really care about uptodate accessed/dirty bits
-- where ptep_get() is used nowadays.
One way to approach that I had in mind was having an explicit interface:
ptep_get()
ptep_get_uptodate()
ptep_get_lockless()
ptep_get_lockless_uptodate()
Especially the last one might not be needed.
Futher, "uptodate" might not be the best choice because of
PageUptodate() and friends. But it's better than
"youngdirty"/"noyoungdirty" IMHO.
Of course, any such changes require care and are better done one step at
at time separately.
--
Cheers,
David / dhildenb
