From: Barry Song <v-songbaohua@xxxxxxxx> To streamline maintenance efforts, we propose discontinuing the use of swap_free(). Instead, we can simply invoke swap_free_nr() with nr set to 1. This adjustment offers the advantage of enabling batch processing within kernel/power/swap.c. Furthermore, swap_free_nr() is designed with a bitmap consisting of only one long, resulting in overhead that can be ignored for cases where nr equals 1. Suggested-by: "Huang, Ying" <ying.huang@xxxxxxxxx> Signed-off-by: Barry Song <v-songbaohua@xxxxxxxx> Cc: "Rafael J. Wysocki" <rafael@xxxxxxxxxx> Cc: Pavel Machek <pavel@xxxxxx> Cc: Len Brown <len.brown@xxxxxxxxx> Cc: Hugh Dickins <hughd@xxxxxxxxxx> --- include/linux/swap.h | 5 ----- kernel/power/swap.c | 7 +++---- mm/memory.c | 2 +- mm/rmap.c | 4 ++-- mm/shmem.c | 4 ++-- mm/swapfile.c | 19 +++++-------------- 6 files changed, 13 insertions(+), 28 deletions(-) diff --git a/include/linux/swap.h b/include/linux/swap.h index d1d35e92d7e9..f03cb446124e 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -482,7 +482,6 @@ extern int add_swap_count_continuation(swp_entry_t, gfp_t); extern void swap_shmem_alloc(swp_entry_t); extern int swap_duplicate(swp_entry_t); extern int swapcache_prepare(swp_entry_t); -extern void swap_free(swp_entry_t); extern void swap_free_nr(swp_entry_t entry, int nr_pages); extern void swapcache_free_entries(swp_entry_t *entries, int n); extern void free_swap_and_cache_nr(swp_entry_t entry, int nr); @@ -561,10 +560,6 @@ static inline int swapcache_prepare(swp_entry_t swp) return 0; } -static inline void swap_free(swp_entry_t swp) -{ -} - static inline void swap_free_nr(swp_entry_t entry, int nr_pages) { } diff --git a/kernel/power/swap.c b/kernel/power/swap.c index 5bc04bfe2db1..6befaa88a342 100644 --- a/kernel/power/swap.c +++ b/kernel/power/swap.c @@ -181,7 +181,7 @@ sector_t alloc_swapdev_block(int swap) offset = swp_offset(get_swap_page_of_type(swap)); if (offset) { if (swsusp_extents_insert(offset)) - swap_free(swp_entry(swap, offset)); + swap_free_nr(swp_entry(swap, offset), 1); else return swapdev_block(swap, offset); } @@ -200,12 +200,11 @@ void free_all_swap_pages(int swap) while ((node = swsusp_extents.rb_node)) { struct swsusp_extent *ext; - unsigned long offset; ext = rb_entry(node, struct swsusp_extent, node); rb_erase(node, &swsusp_extents); - for (offset = ext->start; offset <= ext->end; offset++) - swap_free(swp_entry(swap, offset)); + swap_free_nr(swp_entry(swap, ext->start), + ext->end - ext->start + 1); kfree(ext); } diff --git a/mm/memory.c b/mm/memory.c index eea6e4984eae..f033eb3528ba 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -4225,7 +4225,7 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) * We're already holding a reference on the page but haven't mapped it * yet. */ - swap_free(entry); + swap_free_nr(entry, 1); if (should_try_to_free_swap(folio, vma, vmf->flags)) folio_free_swap(folio); diff --git a/mm/rmap.c b/mm/rmap.c index 087a79f1f611..39ec7742acec 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1865,7 +1865,7 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma, goto walk_done_err; } if (arch_unmap_one(mm, vma, address, pteval) < 0) { - swap_free(entry); + swap_free_nr(entry, 1); set_pte_at(mm, address, pvmw.pte, pteval); goto walk_done_err; } @@ -1873,7 +1873,7 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma, /* See folio_try_share_anon_rmap(): clear PTE first. */ if (anon_exclusive && folio_try_share_anon_rmap_pte(folio, subpage)) { - swap_free(entry); + swap_free_nr(entry, 1); set_pte_at(mm, address, pvmw.pte, pteval); goto walk_done_err; } diff --git a/mm/shmem.c b/mm/shmem.c index fa2a0ed97507..bfc8a2beb24f 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1836,7 +1836,7 @@ static void shmem_set_folio_swapin_error(struct inode *inode, pgoff_t index, * in shmem_evict_inode(). */ shmem_recalc_inode(inode, -1, -1); - swap_free(swap); + swap_free_nr(swap, 1); } /* @@ -1927,7 +1927,7 @@ static int shmem_swapin_folio(struct inode *inode, pgoff_t index, delete_from_swap_cache(folio); folio_mark_dirty(folio); - swap_free(swap); + swap_free_nr(swap, 1); put_swap_device(si); *foliop = folio; diff --git a/mm/swapfile.c b/mm/swapfile.c index ec12f2b9d229..ddcd0f24b9a1 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -1343,19 +1343,6 @@ static void swap_entry_free(struct swap_info_struct *p, swp_entry_t entry) swap_range_free(p, offset, 1); } -/* - * Caller has made sure that the swap device corresponding to entry - * is still around or has not been recycled. - */ -void swap_free(swp_entry_t entry) -{ - struct swap_info_struct *p; - - p = _swap_info_get(entry); - if (p) - __swap_entry_free(p, entry); -} - static void cluster_swap_free_nr(struct swap_info_struct *sis, unsigned long offset, int nr_pages) { @@ -1385,6 +1372,10 @@ static void cluster_swap_free_nr(struct swap_info_struct *sis, unlock_cluster_or_swap_info(sis, ci); } +/* + * Caller has made sure that the swap device corresponding to entry + * is still around or has not been recycled. + */ void swap_free_nr(swp_entry_t entry, int nr_pages) { int nr; @@ -1930,7 +1921,7 @@ static int unuse_pte(struct vm_area_struct *vma, pmd_t *pmd, new_pte = pte_mkuffd_wp(new_pte); setpte: set_pte_at(vma->vm_mm, addr, pte, new_pte); - swap_free(entry); + swap_free_nr(entry, 1); out: if (pte) pte_unmap_unlock(pte, ptl); -- 2.34.1