Re: [PATCH v2 1/1] selftests/proc: use RSS in /proc/pid/smaps_rollup tearing tests

[Suren Baghdasaryan]

On Mon, Nov 2, 2026 at 9:21 AM Suren Baghdasaryan <surenb@xxxxxxxxxx> wrote:
>
> On Mon, Nov 2, 2026 at 9:01 AM Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
> >
> > On Mon, 2 Nov 2026 08:15:47 -0800 Suren Baghdasaryan <surenb@xxxxxxxxxx> wrote:
> >
> > > > Ah, I see now why handling READ_IMPLIES_EXEC is needed. Then your
> > > > complete fix looks fine. Perhaps we should mention this pre-ARMv6 CPU
> > > > detail in the changelog of your fix to explain why READ_IMPLIES_EXEC
> > > > is important here?
> > >
> > > I guess I have to ask whether you want to post your fix as a followup
> > > to mine or if I should fold them into one patch and post a v3. What's
> > > your preference?
> >
> > yes, please just prepare a v3.  I don't think bot will be offended.
>
> Ok, I'll wait a day for others to take a look and will post v3.
> Thanks!

I posted v3 at https://lore.kernel.org/all/20261104015447.363602-1-surenb@xxxxxxxxxx/

Pedro, I confirm that page migration will not change Rss even
temporarily because pagetable changes are made under the PTE lock and
smaps walk takes the same lock. It will see either a present PTE or a
migration entry which it also counts in Rss (via
smaps_account(present=false)).