[RFC,13/39] mm/rmap: factor out adding folio mappings into __folio_add_rmap()
Commit Message
Let's factor it out to prepare for reuse as we convert
page_add_anon_rmap() to folio_add_anon_rmap_[pte|ptes|pmd]().
Make the compiler always special-case on the granularity by using
__always_inline.
Signed-off-by: David Hildenbrand <david@redhat.com>
---
mm/rmap.c | 75 +++++++++++++++++++++++++++++++------------------------
1 file changed, 42 insertions(+), 33 deletions(-)
Comments
On 12/4/2023 10:21 PM, David Hildenbrand wrote:
> Let's factor it out to prepare for reuse as we convert
> page_add_anon_rmap() to folio_add_anon_rmap_[pte|ptes|pmd]().
>
> Make the compiler always special-case on the granularity by using
> __always_inline.
>
> Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Yin Fengwei <fengwei.yin@intel.com>
> ---
> mm/rmap.c | 75 +++++++++++++++++++++++++++++++------------------------
> 1 file changed, 42 insertions(+), 33 deletions(-)
>
> diff --git a/mm/rmap.c b/mm/rmap.c
> index 53e2c653be99a..c09b360402599 100644
> --- a/mm/rmap.c
> +++ b/mm/rmap.c
> @@ -1127,6 +1127,46 @@ int folio_total_mapcount(struct folio *folio)
> return mapcount;
> }
>
> +static __always_inline unsigned int __folio_add_rmap(struct folio *folio,
> + struct page *page, unsigned int nr_pages, enum rmap_mode mode,
> + int *nr_pmdmapped)
> +{
> + atomic_t *mapped = &folio->_nr_pages_mapped;
> + int first, nr = 0;
> +
> + __folio_rmap_sanity_checks(folio, page, nr_pages, mode);
> +
> + /* Is page being mapped by PTE? Is this its first map to be added? */
> + if (likely(mode == RMAP_MODE_PTE)) {
> + do {
> + first = atomic_inc_and_test(&page->_mapcount);
> + if (first && folio_test_large(folio)) {
> + first = atomic_inc_return_relaxed(mapped);
> + first = (first < COMPOUND_MAPPED);
> + }
> +
> + if (first)
> + nr++;
> + } while (page++, --nr_pages > 0);
> + } else if (mode == RMAP_MODE_PMD) {
> + first = atomic_inc_and_test(&folio->_entire_mapcount);
> + if (first) {
> + nr = atomic_add_return_relaxed(COMPOUND_MAPPED, mapped);
> + if (likely(nr < COMPOUND_MAPPED + COMPOUND_MAPPED)) {
> + *nr_pmdmapped = folio_nr_pages(folio);
> + nr = *nr_pmdmapped - (nr & FOLIO_PAGES_MAPPED);
> + /* Raced ahead of a remove and another add? */
> + if (unlikely(nr < 0))
> + nr = 0;
> + } else {
> + /* Raced ahead of a remove of COMPOUND_MAPPED */
> + nr = 0;
> + }
> + }
> + }
> + return nr;
> +}
> +
> /**
> * folio_move_anon_rmap - move a folio to our anon_vma
> * @folio: The folio to move to our anon_vma
> @@ -1338,42 +1378,11 @@ static __always_inline void __folio_add_file_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;
> - unsigned int nr_pmdmapped = 0, first;
> - int nr = 0;
> + unsigned int nr, nr_pmdmapped = 0;
>
> VM_WARN_ON_FOLIO(folio_test_anon(folio), folio);
> - __folio_rmap_sanity_checks(folio, page, nr_pages, mode);
> -
> - /* Is page being mapped by PTE? Is this its first map to be added? */
> - if (likely(mode == RMAP_MODE_PTE)) {
> - do {
> - first = atomic_inc_and_test(&page->_mapcount);
> - if (first && folio_test_large(folio)) {
> - first = atomic_inc_return_relaxed(mapped);
> - first = (first < COMPOUND_MAPPED);
> - }
> -
> - if (first)
> - nr++;
> - } while (page++, --nr_pages > 0);
> - } else if (mode == RMAP_MODE_PMD) {
> - first = atomic_inc_and_test(&folio->_entire_mapcount);
> - if (first) {
> - nr = atomic_add_return_relaxed(COMPOUND_MAPPED, mapped);
> - if (likely(nr < COMPOUND_MAPPED + COMPOUND_MAPPED)) {
> - nr_pmdmapped = folio_nr_pages(folio);
> - nr = nr_pmdmapped - (nr & FOLIO_PAGES_MAPPED);
> - /* Raced ahead of a remove and another add? */
> - if (unlikely(nr < 0))
> - nr = 0;
> - } else {
> - /* Raced ahead of a remove of COMPOUND_MAPPED */
> - nr = 0;
> - }
> - }
> - }
>
> + nr = __folio_add_rmap(folio, page, nr_pages, mode, &nr_pmdmapped);
> if (nr_pmdmapped)
> __lruvec_stat_mod_folio(folio, folio_test_swapbacked(folio) ?
> NR_SHMEM_PMDMAPPED : NR_FILE_PMDMAPPED, nr_pmdmapped);
@@ -1127,6 +1127,46 @@ int folio_total_mapcount(struct folio *folio)
return mapcount;
}
+static __always_inline unsigned int __folio_add_rmap(struct folio *folio,
+ struct page *page, unsigned int nr_pages, enum rmap_mode mode,
+ int *nr_pmdmapped)
+{
+ atomic_t *mapped = &folio->_nr_pages_mapped;
+ int first, nr = 0;
+
+ __folio_rmap_sanity_checks(folio, page, nr_pages, mode);
+
+ /* Is page being mapped by PTE? Is this its first map to be added? */
+ if (likely(mode == RMAP_MODE_PTE)) {
+ do {
+ first = atomic_inc_and_test(&page->_mapcount);
+ if (first && folio_test_large(folio)) {
+ first = atomic_inc_return_relaxed(mapped);
+ first = (first < COMPOUND_MAPPED);
+ }
+
+ if (first)
+ nr++;
+ } while (page++, --nr_pages > 0);
+ } else if (mode == RMAP_MODE_PMD) {
+ first = atomic_inc_and_test(&folio->_entire_mapcount);
+ if (first) {
+ nr = atomic_add_return_relaxed(COMPOUND_MAPPED, mapped);
+ if (likely(nr < COMPOUND_MAPPED + COMPOUND_MAPPED)) {
+ *nr_pmdmapped = folio_nr_pages(folio);
+ nr = *nr_pmdmapped - (nr & FOLIO_PAGES_MAPPED);
+ /* Raced ahead of a remove and another add? */
+ if (unlikely(nr < 0))
+ nr = 0;
+ } else {
+ /* Raced ahead of a remove of COMPOUND_MAPPED */
+ nr = 0;
+ }
+ }
+ }
+ return nr;
+}
+
/**
* folio_move_anon_rmap - move a folio to our anon_vma
* @folio: The folio to move to our anon_vma
@@ -1338,42 +1378,11 @@ static __always_inline void __folio_add_file_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;
- unsigned int nr_pmdmapped = 0, first;
- int nr = 0;
+ unsigned int nr, nr_pmdmapped = 0;
VM_WARN_ON_FOLIO(folio_test_anon(folio), folio);
- __folio_rmap_sanity_checks(folio, page, nr_pages, mode);
-
- /* Is page being mapped by PTE? Is this its first map to be added? */
- if (likely(mode == RMAP_MODE_PTE)) {
- do {
- first = atomic_inc_and_test(&page->_mapcount);
- if (first && folio_test_large(folio)) {
- first = atomic_inc_return_relaxed(mapped);
- first = (first < COMPOUND_MAPPED);
- }
-
- if (first)
- nr++;
- } while (page++, --nr_pages > 0);
- } else if (mode == RMAP_MODE_PMD) {
- first = atomic_inc_and_test(&folio->_entire_mapcount);
- if (first) {
- nr = atomic_add_return_relaxed(COMPOUND_MAPPED, mapped);
- if (likely(nr < COMPOUND_MAPPED + COMPOUND_MAPPED)) {
- nr_pmdmapped = folio_nr_pages(folio);
- nr = nr_pmdmapped - (nr & FOLIO_PAGES_MAPPED);
- /* Raced ahead of a remove and another add? */
- if (unlikely(nr < 0))
- nr = 0;
- } else {
- /* Raced ahead of a remove of COMPOUND_MAPPED */
- nr = 0;
- }
- }
- }
+ nr = __folio_add_rmap(folio, page, nr_pages, mode, &nr_pmdmapped);
if (nr_pmdmapped)
__lruvec_stat_mod_folio(folio, folio_test_swapbacked(folio) ?
NR_SHMEM_PMDMAPPED : NR_FILE_PMDMAPPED, nr_pmdmapped);