+static __always_inline void __folio_remove_rmap(struct folio *folio,
+ struct page *page, unsigned int nr_pages,
+ struct vm_area_struct *vma, enum rmap_mode mode)
+{
atomic_t *mapped = &folio->_nr_pages_mapped;
- int nr = 0, nr_pmdmapped = 0;
- bool last;
+ int last, nr = 0, nr_pmdmapped = 0;
nit: you're being inconsistent across the functions with signed vs unsigned for
page counts (e.g. nr, nr_pmdmapped) - see __folio_add_rmap(),
__folio_add_file_rmap(), __folio_add_anon_rmap().
Definitely.
I suggest pick one and stick to it. Personally I'd go with signed int (since
that's what all the counters in struct folio that we are manipulating are,
underneath the atomic_t) then check that nr_pages > 0 in
__folio_rmap_sanity_checks().
Can do, but note that the counters are signed to detect udnerflows. It
doesn't make sense here to pass a negative number.
enum node_stat_item idx;
- VM_WARN_ON_FOLIO(folio_test_hugetlb(folio), folio);
- VM_BUG_ON_PAGE(compound && !PageHead(page), page);
+ __folio_rmap_sanity_checks(folio, page, nr_pages, mode);
/* Is page being unmapped by PTE? Is this its last map to be removed? */
- if (likely(!compound)) {
- last = atomic_add_negative(-1, &page->_mapcount);
- nr = last;
- if (last && folio_test_large(folio)) {
- nr = atomic_dec_return_relaxed(mapped);
- nr = (nr < COMPOUND_MAPPED);
- }
- } else if (folio_test_pmd_mappable(folio)) {
- /* That test is redundant: it's for safety or to optimize out */
+ if (likely(mode == RMAP_MODE_PTE)) {
+ do {
+ last = atomic_add_negative(-1, &page->_mapcount);
+ if (last && folio_test_large(folio)) {
+ last = atomic_dec_return_relaxed(mapped);
+ last = (last < COMPOUND_MAPPED);
+ }
+ if (last)
+ nr++;
+ } while (page++, --nr_pages > 0);
+ } else if (mode == RMAP_MODE_PMD) {
last = atomic_add_negative(-1, &folio->_entire_mapcount);
if (last) {
nr = atomic_sub_return_relaxed(COMPOUND_MAPPED, mapped);
@@ -1517,7 +1528,7 @@ void page_remove_rmap(struct page *page, struct vm_area_struct *vma,
* is still mapped.
*/
if (folio_test_pmd_mappable(folio) && folio_test_anon(folio))
folio_test_pmd_mappable() -> folio_test_large()
Since you're converting this to support batch PTE removal, it might as well also
support smaller-than-pmd too?
I remember that you have a patch for that, right? :)
I currently have a patch to do this same change in the multi-size THP series.
Ah, yes, and that should go in first.
--
Cheers,
David / dhildenb
