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a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1794753576; bh=zA70M/FX7BJCJkrrfkJkpzOjUbXIa1jcfVlm2yKz02c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=d6oHpRZrTTfSPkJ7wYBRg9DyuIJQ8SN8/qSd8501rLb9HwRI0mjPiXob7qKS+lJkP Kt0u4URQoV+NDz0Lh4J8JNl69basL3kw7HqoDwJgMuzAe7wzerwVMxwIgADF4SViYT JUzXRuc3qDgnHAtrGUj7x4d3jLG2rP3+gc3+OeZw= From: Dev Jain To: david@kernel.org, ljs@kernel.org, akpm@linux-foundation.org, hughd@google.com, chrisl@kernel.org, kasong@tencent.com, davem@davemloft.net, andreas@gaisler.com Cc: Dev Jain , riel@surriel.com, liam@infradead.org, vbabka@kernel.org, harry@kernel.org, jannh@google.com, lance.yang@linux.dev, baolin.wang@linux.alibaba.com, shikemeng@huaweicloud.com, nphamcs@gmail.com, baoquan.he@linux.dev, baohua@kernel.org, youngjun.park@lge.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, rppt@kernel.org, surenb@google.com, mhocko@suse.com, pfalcato@suse.de, anshuman.khandual@arm.com, geert@linux-m68k.org, sparclinux@vger.kernel.org, ryan.roberts@arm.com Subject: [PATCH v4 2/9] mm/swapfile: add batched version of folio_put_swap Date: Sun, 15 Nov 2026 14:38:57 +0000 Message-ID: <20261115143905.3045084-3-dev.jain@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20261115143905.3045084-1-dev.jain@arm.com> References: <20261115143905.3045084-1-dev.jain@arm.com> X-Archived-By: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Stat-Signature: 8zf5t931pnbknwh4pcop8fxgsb5d8e1s X-Rspam-User: X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 746F61C0006 X-Spam-Status: No, score=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_PASS, SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=4.0.1 X-HE-Tag: 1794753577-715399 X-HE-Meta: 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 RdjNZe17 OuNY8PAYofKgxckY0gkocvVGk6ge32WZgia9U3gUGiaH2Tyx4GOowOCVPF9DoM/Q0GM3IN158d9GQl+0ggtIG5V9QmfmgoHCgQKCFrFEcpz/PJTEC+huq9sWo2ZJTOEIudinuteMx51saypJgWXDIsANcX6di6HEAO3ofnZkbVRGBfl/ihfi5IMWMKwmZri1qK/HWTAQBJHEH1YgfKYsgye+6HrgtAMXsdVEXZg2YuK5oNDNizz2VmVc1YvTnRivYl7ZOGoSV1CBtS/6Oc/mG2MW19JC6oxW6Fj62mAvI0+ELyvIrkqwAHf7TtZFJem9hSi7MtjOv+Eg4/F57Gi3l4Qexdg== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 Add folio_put_swap_pages to handle a batch of consecutive pages. Note that folio_put_swap already can handle a subset of this: nr_pages == 1 and nr_pages == folio_nr_pages(folio). Generalize this to any nr_pages. Currently we have a not-so-nice logic of passing in subpage == NULL if we mean to exercise the logic on the entire folio, and subpage != NULL if we want to exercise the logic on only that subpage. Remove this indirection: the caller invokes folio_put_swap_pages() if it wants to operate on a range of pages in the folio (i.e nr_pages may be anything between 1 and folio_nr_pages()), and invokes folio_put_swap() if it wants to operate on the entire folio. Acked-by: David Hildenbrand (Arm) Reviewed-by: Kairui Song Reviewed-by: Barry Song Signed-off-by: Dev Jain --- mm/memory.c | 9 +++++---- mm/rmap.c | 4 ++-- mm/shmem.c | 6 +++--- mm/swap.h | 17 +++++++++++++++-- mm/swapfile.c | 21 ++++++++++----------- 5 files changed, 35 insertions(+), 22 deletions(-) diff --git a/mm/memory.c b/mm/memory.c index d477a4f986bc8..d8466be900d59 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -5285,8 +5285,9 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) if (unlikely(folio != swapcache)) { folio_add_new_anon_rmap(folio, vma, address, RMAP_EXCLUSIVE); folio_add_lru_vma(folio, vma); - folio_put_swap(swapcache, - folio_file_page(swapcache, swp_offset(entry))); + folio_put_swap_pages(swapcache, + folio_file_page(swapcache, swp_offset(entry)), + 1); } else if (!folio_test_anon(folio)) { /* * We currently only expect !anon folios that are fully @@ -5295,12 +5296,12 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) VM_WARN_ON_ONCE_FOLIO(folio_nr_pages(folio) != nr_pages, folio); VM_WARN_ON_ONCE_FOLIO(folio_mapped(folio), folio); folio_add_new_anon_rmap(folio, vma, address, rmap_flags); - folio_put_swap(folio, NULL); + folio_put_swap(folio); } else { VM_WARN_ON_ONCE(nr_pages != 1 && nr_pages != folio_nr_pages(folio)); folio_add_anon_rmap_ptes(folio, page, nr_pages, vma, address, rmap_flags); - folio_put_swap(folio, nr_pages == 1 ? page : NULL); + folio_put_swap_pages(folio, page, nr_pages); } VM_BUG_ON(!folio_test_anon(folio) || diff --git a/mm/rmap.c b/mm/rmap.c index 512a3a1c63c73..6a6fb9b56f2cd 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -2174,13 +2174,13 @@ static bool ttu_anon_swapbacked_folio(struct vm_area_struct *vma, * so we'll not check/care. */ if (arch_unmap_one(mm, vma, address, pteval) < 0) { - folio_put_swap(folio, page); + folio_put_swap_pages(folio, page, 1); return false; } /* See folio_try_share_anon_rmap(): clear PTE first. */ if (anon_exclusive && folio_try_share_anon_rmap_pte(folio, page)) { - folio_put_swap(folio, page); + folio_put_swap_pages(folio, page, 1); return false; } diff --git a/mm/shmem.c b/mm/shmem.c index e3db6e45cae0c..e0c6037eba59a 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1980,7 +1980,7 @@ int shmem_writeout(struct swap_io_ctx *ctx, struct folio *folio, /* Swap entry might be erased by racing shmem_free_swap() */ if (!error) { shmem_recalc_inode(inode, 0, -nr_pages); - folio_put_swap(folio, NULL); + folio_put_swap(folio); } shmem_allow_eviction(info); @@ -2414,7 +2414,7 @@ static void shmem_set_folio_swapin_error(struct inode *inode, pgoff_t index, nr_pages = folio_nr_pages(folio); folio_wait_writeback(folio); - folio_put_swap(folio, NULL); + folio_put_swap(folio); swap_cache_del_folio(folio); /* * Let shmem_recalc_inode() reduce alloced and release the block charge @@ -2648,7 +2648,7 @@ static int shmem_swapin_folio(struct inode *inode, pgoff_t index, if (sgp == SGP_WRITE) folio_mark_accessed(folio); - folio_put_swap(folio, NULL); + folio_put_swap(folio); swap_cache_del_folio(folio); folio_mark_dirty(folio); put_swap_device(si); diff --git a/mm/swap.h b/mm/swap.h index cbcfd587aac1a..9c89c0e848396 100644 --- a/mm/swap.h +++ b/mm/swap.h @@ -247,7 +247,8 @@ extern int swap_retry_table_alloc(swp_entry_t entry, gfp_t gfp); int folio_alloc_swap(struct folio *folio); int folio_dup_swap_pages(struct folio *folio, struct page *page, unsigned long nr_pages); -void folio_put_swap(struct folio *folio, struct page *page); +void folio_put_swap_pages(struct folio *folio, struct page *page, + unsigned long nr_pages); /* For internal use */ extern void __swap_cluster_free_entries(struct swap_info_struct *si, @@ -394,7 +395,8 @@ static inline int folio_dup_swap_pages(struct folio *folio, struct page *page, return -EINVAL; } -static inline void folio_put_swap(struct folio *folio, struct page *page) +static inline void folio_put_swap_pages(struct folio *folio, struct page *page, + unsigned long nr_pages) { } @@ -503,6 +505,17 @@ static inline int folio_dup_swap(struct folio *folio) folio_nr_pages(folio)); } +/** + * folio_put_swap() - Decrease swap count of all swap entries of a folio. + * @folio: folio with swap entries bound. + * + * See folio_put_swap_pages() for more information. + */ +static inline void folio_put_swap(struct folio *folio) +{ + folio_put_swap_pages(folio, folio_page(folio, 0), folio_nr_pages(folio)); +} + static inline bool swap_cache_folio_mappable(struct folio *folio, unsigned int nr_pages) { diff --git a/mm/swapfile.c b/mm/swapfile.c index d46cb1cf6469d..d1de36296fb1a 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -1892,27 +1892,25 @@ int folio_dup_swap_pages(struct folio *folio, struct page *page, } /** - * folio_put_swap() - Decrease swap count of swap entries of a folio. + * folio_put_swap_pages() - Decrease swap count of swap entries of a folio. * @folio: folio with swap entries bounded, must be in swap cache and locked. - * @page: if not NULL, only decrease the swap count of this page. + * @page: the first page in the folio to decrease the swap count for. + * @nr_pages: the number of pages in the folio to decrease the swap count for. * * This won't free the swap slots even if swap count drops to zero, they are * still pinned by the swap cache. User may call folio_free_swap to free them. * Context: Caller must ensure the folio is locked and in the swap cache. */ -void folio_put_swap(struct folio *folio, struct page *page) +void folio_put_swap_pages(struct folio *folio, struct page *page, + unsigned long nr_pages) { - swp_entry_t entry = folio->swap; - unsigned long nr_pages = folio_nr_pages(folio); + swp_entry_t entry = folio_page_swap_entry(folio, page); struct swap_info_struct *si = __swap_entry_to_info(entry); + unsigned long idx = folio_page_idx(folio, page); VM_WARN_ON_FOLIO(!folio_test_locked(folio), folio); VM_WARN_ON_FOLIO(!folio_test_swapcache(folio), folio); - - if (page) { - entry = folio_page_swap_entry(folio, page); - nr_pages = 1; - } + VM_WARN_ON_FOLIO(idx + nr_pages > folio_nr_pages(folio), folio); swap_put_entries_cluster(si, swp_offset(entry), nr_pages, false); } @@ -2658,7 +2656,8 @@ static int unuse_pte(struct vm_area_struct *vma, pmd_t *pmd, setpte: set_pte_at(vma->vm_mm, addr, pte, new_pte); - folio_put_swap(swapcache, folio_file_page(swapcache, swp_offset(entry))); + folio_put_swap_pages(swapcache, + folio_file_page(swapcache, swp_offset(entry)), 1); out: if (pte) pte_unmap_unlock(pte, ptl); -- 2.43.0