Re: [RFC] Unconditionally lock folios when calling rmap_walk()

From: Lorenzo Stoakes
Date: Fri Aug 22 2025 - 06:53:17 EST


Lokesh, this is a mess :/

I've been a reverse mapping co-maintainer for 4 months now, please check
MAINTAINERS before sending this stuff out. It's not really impressive to
learn about this 2nd hand...

Also I cannot get lei to get this mail to me, no matter how hard I try. So
it's _really hard_ for me to respond to this.

And you label this '[RFC]' but I can't find any code (unless it's lost in
the thread somehow). It should be '[DISCUSSION]'.

rmap locking is _extremely_ sensitive and the discussion needs careful
attention.

It's hard for me to even track what's going on here or join the discussion,
could you just please resend, correctly cc'ing the maintainers/reviewers of
rmap, and prefix with '[DISCUSSION]'?

You've already got responses here so we're inevitably going to fork the
conversation, but unfortunately I don't see any way around this, because
I'm going to miss all the conversation that I'm not cc'd on.

Anwyay I simply can't engage on this as-is, and I really _want to_, because
rmap and the locking around it are issues of PRIMARY importance to me.

Please try to make my life easier :)

Thanks, Lorenzo