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t=1788241465; bh=E2ktIYiViPu9MnUaU8AeLIAVoGUmKFh4+m0Y1CBWS4o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BK9TIEMFCOEDM5tAyRTeOzg/0PPizZCgEpvn0On2eINATQ6RHoSeKLHTLRcmI4NGk VhIdCsAPgy2d2/fwOlTLKYpkwDAU69IXATxDssn/+V06oTCebY6DuU/YpX58ZU42MQ nYHTpOmHVwtSvuD0jemjfqhEb5b0A9nwHPq1z2Dk= From: Dev Jain To: akpm@linux-foundation.org, david@kernel.org, ljs@kernel.org, hughd@google.com, chrisl@kernel.org, kasong@tencent.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, ryan.roberts@arm.com, anshuman.khandual@arm.com Subject: [PATCH v2 2/8] mm/swapfile: add batched version of folio_put_swap Date: Tue, 1 Sep 2026 05:43:49 +0000 Message-ID: <20260901054358.4049095-3-dev.jain@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260901054358.4049095-1-dev.jain@arm.com> References: <20260901054358.4049095-1-dev.jain@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: A267140008 X-Stat-Signature: riw65bo93zwap7au9n8ixznzb1hs5h8o X-Rspam-User: X-HE-Tag: 1788241466-223792 X-HE-Meta: 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 KljBDQw6 2sWQfeGCHH4MmhC20Cu99gvW2y3qFJne+5fXVtNNarL88n2xFRgHZT2g00m3ZgjgJ5QDHqNhWI7nPlnSTPgleXzNUgcn3ng30N6GLo+BPKSU5u3Dw7F+HpEbOR07YhPv08apXfZ9C7/Bf86MaGmfO3iP1Z0gEZxmpXwE3IsBi3OzNh8asAo0p8q/y25aokRsNy0x/qNmZ2wITwaZ2HbrFS9ye7mP58JUo0DEjgC58hHuS4EcC1xqgzzGFZs+2ybLgpbG8dlkIC/RoKc91qbGCxjwE7g2PXkpIDvCIZ63avdszpjyfOauOrXoT6F4JVdn+uMtq Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: 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) Signed-off-by: Dev Jain Reviewed-by: Barry Song --- mm/memory.c | 6 +++--- mm/rmap.c | 4 ++-- mm/shmem.c | 6 +++--- mm/swap.h | 17 +++++++++++++++-- mm/swapfile.c | 19 ++++++++++--------- 5 files changed, 33 insertions(+), 19 deletions(-) diff --git a/mm/memory.c b/mm/memory.c index 8b0c2c735d3de..6cfea4faf0588 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -5202,7 +5202,7 @@ 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, NULL); + folio_put_swap(swapcache); } else if (!folio_test_anon(folio)) { /* * We currently only expect !anon folios that are fully @@ -5211,12 +5211,12 @@ 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 0a4aa06b66de6..1b9f07d4d1be9 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -2157,13 +2157,13 @@ 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 6cea018d69f04..316bf14136d63 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1733,7 +1733,7 @@ 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); } /* @@ -2163,7 +2163,7 @@ 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); /* * Don't treat swapin error folio as alloced. Otherwise inode->i_blocks @@ -2393,7 +2393,7 @@ 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 f52ecbedae8b8..0e0d00bf4daa6 100644 --- a/mm/swap.h +++ b/mm/swap.h @@ -246,7 +246,8 @@ 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, @@ -375,7 +376,8 @@ 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) { } @@ -477,6 +479,17 @@ 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)); +} + extern const struct swap_ops swap_bdev_ops; int shmem_writeout(struct swap_io_ctx *ctx, struct folio *folio, diff --git a/mm/swapfile.c b/mm/swapfile.c index 25bb6fc562c57..da5e66bdcef10 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -1819,27 +1819,27 @@ 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); 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); + VM_WARN_ON_FOLIO(idx + nr_pages > folio_nr_pages(folio), folio); - if (page) { - entry.val += folio_page_idx(folio, page); - nr_pages = 1; - } + entry.val += idx; swap_put_entries_cluster(si, swp_offset(entry), nr_pages, false); } @@ -2518,7 +2518,8 @@ 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