+ nr = madvise_folio_pte_batch(addr, end, folio, pte,
+ ptent, &any_young, &any_dirty);
+
+ if (nr < folio_nr_pages(folio)) {
+ if (folio_likely_mapped_shared(folio))
+ continue;
+
+ arch_leave_lazy_mmu_mode();
+ if (madvise_pte_split_folio(mm, pmd, addr,
+ folio, &start_pte, &ptl))
+ nr = 0;
+ if (!start_pte)
+ break;
+ pte = start_pte;
+ arch_enter_lazy_mmu_mode();
+ continue;
+ }
+
+ if (any_young)
+ ptent = pte_mkyoung(ptent);
+ if (any_dirty)
+ ptent = pte_mkdirty(ptent);
}
+ if (folio_mapcount(folio) != folio_nr_pages(folio))
+ continue;
Why is this here? I thought we had previously concluded to only do this test
inside the below if statement (where you have it duplicated).
I stumbled over these same while reviewing. It's not exactly duplicate,
because it's unreliable without the folio lock. It looks more like an
best-effort early check.
But then, we also add it to cases where we previously wouldn't check the
mapcount at all: when the folio was added to the swapcache or is already
dirty.
In that case, we would even see a change for order-0 folios with that
new check.
--
Cheers,
David / dhildenb
