From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 07CD930677E for ; Tue, 15 Sep 2026 00:45:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789433120; cv=none; b=c7rt+8KTil3ezWVyt66LCmXDBzyIIo+T3/OhlZZQlFfpiCP/9QvDzweJregokTeiy8fQ1ibu8ZrQTqrpfDMLV4zzn2MZ2zXDelJP4xg4ctJ7fQ380rtfX6RLLySoQtklrO0gyxU5sEVl220ttzz3kriF7Y3Tg+HC0h1gtmGMdwQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789433120; c=relaxed/simple; bh=CO/lWonesiSi/5E6JF/sVW4xsNx2elXhmn5g6K6Aanw=; h=Date:To:From:Subject:Message-Id; b=IrHI/B/2pntmhy5AhtiKi5RrEnEPGl1HJBr7PSOP5q/VKeoD8WGkfo+olCsNC/SbtNxCg9FvZA+y6n6wExYszkfwLG1FoFfMFBskZrtjBKZVH8ymp1PHqYfPbTgn6dNq2b0kuSXZ0d3cHuOjgw9NnxOzVFjkTDe1sk6vRlta16I= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=dXeZ3+Q1; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="dXeZ3+Q1" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4EC901F000FF; Tue, 15 Sep 2026 00:45:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1789433115; bh=MTNgCJLT/z9NmLZBT1d9/5Ei9OTQpOxwUUCZD8vs2mU=; h=Date:To:From:Subject; b=dXeZ3+Q12y8UX5fQmrhYWK7QCI0I3kaPEv+24zqU5UBGmf5W8kaDCbWgKicfd3v5S C4YMXH8jKlno/zzPsmm1oEMpUbg2Vv/PkB5+i/l7cTOLZzjDUe4rLiT128mzIBreIQ l5tH1/Lh2zI0Tww0By6lnNEjvzNIaOyVUJQThP90= Date: Mon, 14 Sep 2026 17:45:14 -0700 To: mm-commits@vger.kernel.org,kasong@tencent.com,akpm@linux-foundation.org From: Andrew Morton Subject: + mm-huge_memory-move-filemap-management-into-the-file-split-helper.patch added to mm-new branch Message-Id: <20260915004515.4EC901F000FF@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: mm/huge_memory: move filemap management into the file split helper has been added to the -mm mm-new branch. Its filename is mm-huge_memory-move-filemap-management-into-the-file-split-helper.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-huge_memory-move-filemap-management-into-the-file-split-helper.patch This patch will later appear in the mm-new branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Note, mm-new is a provisional staging ground for work-in-progress patches, and acceptance into mm-new is a notification for others take notice and to finish up reviews. Please do not hesitate to respond to review feedback and post updated versions to replace or incrementally fixup patches in mm-new. The mm-new branch of mm.git is not included in linux-next If a few days of testing in mm-new is successful, the patch will me moved into mm.git's mm-unstable branch, which is included in linux-next Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via various branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there most days ------------------------------------------------------ From: Kairui Song Subject: mm/huge_memory: move filemap management into the file split helper Date: Tue, 15 Sep 2026 01:14:52 +0800 Only file split needs the filemap and xarray handling and related variables. Move them out of __folio_split() into the file helper so the helper is self-contained, and simplify the parameters. No functional change. Link: https://lore.kernel.org/20260915-swap-thp-cleanup-v5-11-39878b37dfb0@tencent.com Signed-off-by: Kairui Song Signed-off-by: Andrew Morton Reviewed-by: Zi Yan Reviewed-by: Kiryl Shutsemau (Meta) Reviewed-by: Yeoreum Yun Cc: Baolin Wang Cc: Baoquan He Cc: Barry Song Cc: Chris Li Cc: David Hildenbrand (Arm) Cc: Dev Jain Cc: Kemeng Shi Cc: Lance Yang Cc: Liam R. Howlett Cc: Lorenzo Stoakes Cc: Michal Hocko Cc: Mike Rapoport Cc: Nhat Pham Cc: Ryan Roberts Cc: Suren Baghdasaryan Cc: Vlastimil Babka --- mm/huge_memory.c | 102 +++++++++++++++++++-------------------------- 1 file changed, 44 insertions(+), 58 deletions(-) --- a/mm/huge_memory.c~mm-huge_memory-move-filemap-management-into-the-file-split-helper +++ a/mm/huge_memory.c @@ -4107,16 +4107,42 @@ out_no_split: static int __folio_freeze_split_file(struct folio *folio, unsigned int new_order, struct page *split_at, - struct xa_state *xas, struct address_space *mapping, bool do_lru, struct list_head *list, enum split_type split_type) { + struct address_space *mapping = folio->mapping; + XA_STATE(xas, &mapping->i_pages, folio->index); struct folio *end_folio = folio_next(folio); struct folio *new_folio, *next; int nr_shmem_dropped = 0; + unsigned int min_order; struct lruvec *lruvec; pgoff_t end; - int ret; + gfp_t gfp; + int ret = 0; + + min_order = mapping_min_folio_order(mapping); + if (new_order < min_order) + return -EINVAL; + + gfp = current_gfp_context(mapping_gfp_mask(mapping) & GFP_RECLAIM_MASK); + if (!filemap_release_folio(folio, gfp)) + return -EBUSY; + + mapping_set_update(&xas, mapping); + + if (split_type == SPLIT_TYPE_UNIFORM) { + int old_order = folio_order(folio); + + xas_set_order(&xas, folio->index, new_order); + xas_split_alloc(&xas, folio, old_order, gfp); + if (xas_error(&xas)) { + ret = xas_error(&xas); + goto fail_free; + } + } + + i_mmap_lock_read(mapping); /* Currently device private folios can only back anonymous memory. */ VM_WARN_ON_ONCE_FOLIO(folio_is_device_private(folio), folio); @@ -4134,15 +4160,15 @@ static int __folio_freeze_split_file(str ret = unmap_folio(folio); if (ret) - return ret; + goto fail_mmap_unlock; - xas_lock_irq(xas); + xas_lock_irq(&xas); /* * Check if the folio is present in page cache. * We assume all tail are present too, if folio is there. */ - if (xas_load(xas) != folio) { + if (xas_load(&xas) != folio) { ret = -EAGAIN; goto fail; } @@ -4169,7 +4195,7 @@ static int __folio_freeze_split_file(str if (do_lru) lruvec = folio_lruvec_lock(folio); - ret = __split_frozen_folio(folio, new_order, split_at, xas, + ret = __split_frozen_folio(folio, new_order, split_at, &xas, mapping, split_type); /* @@ -4225,9 +4251,19 @@ fail: * If we want to use try_to_migrate() on file in unmap_folio, * remember to add remap_anon_folio() and adapt it. */ - xas_unlock_irq(xas); + xas_unlock_irq(&xas); +fail_mmap_unlock: if (nr_shmem_dropped) shmem_uncharge(mapping->host, nr_shmem_dropped); + /* + * Drop the mapping while the inode is still pinned. @folio stays + * locked and present in the page cache, so eviction cannot free + * the inode yet, nothing past this point may touch the inode or + * the mapping. + */ + i_mmap_unlock_read(mapping); +fail_free: + xas_destroy(&xas); return ret; } @@ -4256,11 +4292,9 @@ static int __folio_split(struct folio *f struct page *split_at, struct page *lock_at, struct list_head *list, enum split_type split_type) { - XA_STATE(xas, &folio->mapping->i_pages, folio->index); struct folio *end_folio = folio_next(folio); bool is_anon = folio_test_anon(folio); struct mem_cgroup *memcg, *old_memcg; - struct address_space *mapping = NULL; struct anon_vma *anon_vma = NULL; int old_order = folio_order(folio); struct folio *new_folio, *next; @@ -4307,61 +4341,16 @@ static int __folio_split(struct folio *f goto out; } anon_vma_lock_write(anon_vma); - mapping = NULL; - } else { - unsigned int min_order; - gfp_t gfp; - - mapping = folio->mapping; - min_order = mapping_min_folio_order(mapping); - if (new_order < min_order) { - ret = -EINVAL; - goto out; - } - - gfp = current_gfp_context(mapping_gfp_mask(mapping) & - GFP_RECLAIM_MASK); - - if (!filemap_release_folio(folio, gfp)) { - ret = -EBUSY; - goto out; - } - - mapping_set_update(&xas, mapping); - - if (split_type == SPLIT_TYPE_UNIFORM) { - xas_set_order(&xas, folio->index, new_order); - xas_split_alloc(&xas, folio, old_order, gfp); - if (xas_error(&xas)) { - ret = xas_error(&xas); - goto out; - } - } - - anon_vma = NULL; - i_mmap_lock_read(mapping); } if (is_anon) ret = __folio_freeze_split_anon(folio, new_order, split_at, true, list, split_type); else - ret = __folio_freeze_split_file(folio, new_order, split_at, &xas, mapping, + ret = __folio_freeze_split_file(folio, new_order, split_at, true, list, split_type); /* - * Drop the mapping while the inode is still pinned. @folio stays - * locked and present in the page cache until the loop below, so - * eviction cannot free the inode yet; @lock_at is not enough, it may - * be a tail beyond EOF that the split already dropped from the page - * cache. Nothing past this point may touch the inode or the mapping. - */ - if (mapping) { - i_mmap_unlock_read(mapping); - mapping = NULL; - } - - /* * Unlock all after-split folios except the one containing * @lock_at page. If @folio is not split, it will be kept locked. */ @@ -4384,14 +4373,11 @@ static int __folio_split(struct folio *f anon_vma_unlock_write(anon_vma); put_anon_vma(anon_vma); } - if (mapping) - i_mmap_unlock_read(mapping); out: /* restore to caller's old_memcg */ set_active_memcg(old_memcg); mem_cgroup_put(memcg); out_no_memcg: - xas_destroy(&xas); if (is_pmd_order(old_order)) count_vm_event(!ret ? THP_SPLIT_PAGE : THP_SPLIT_PAGE_FAILED); count_mthp_stat(old_order, !ret ? MTHP_STAT_SPLIT : MTHP_STAT_SPLIT_FAILED); _ Patches currently in -mm which might be from kasong@tencent.com are mm-memcontrol-move-the-lru_zone_size-sanity-check-to-the-reader-side.patch mm-mglru-introduce-helpers-for-manipulating-gen-and-refs-flags.patch mm-migrate-copy-all-referenced-state-via-folio_migrate_lru_refs.patch mm-mglru-move-max_seq-read-into-walk_update_folio.patch mm-mglru-use-explicit-tier-range-in-read_ctrl_pos.patch mm-mglru-fix-potential-generation-folio-number-leak.patch mm-swap-fix-off-by-one-in-swap-cache-replace-sanity-check.patch mm-huge_memory-fix-rejection-of-swap-cache-folios-with-a-mapping.patch mm-huge_memory-invert-folio_ref_freeze-check-to-reduce-indentation.patch mm-huge_memory-split-the-routine-for-splitting-anon-and-file-folio.patch mm-huge_memory-rename-__split_unmapped_folio-to-__split_frozen_folio.patch mm-huge_memory-consolidate-irq-and-locking-for-folio-split.patch mm-huge_memory-move-eof-trimming-into-the-file-split-helper.patch mm-huge_memory-move-unmap-and-remap-into-the-split-helpers.patch mm-huge_memory-rename-remap_page-to-remap_anon_folio.patch mm-huge_memory-move-the-racy-refcount-check-into-unmap_folio.patch mm-huge_memory-move-filemap-management-into-the-file-split-helper.patch mm-huge_memory-move-anon_vma-handling-into-the-anon-split-helper.patch mm-huge_memory-move-memcg-switch-into-the-file-split-helper.patch mm-huge_memory-drop-the-unused-do_lru-argument-of-the-file-split-helper.patch mm-huge_memory-clean-up-after-split-folio-freeing-in-__folio_split.patch mm-huge_memory-count-only-swap-cache-refs-in-anon-folio-split.patch mm-huge_memory-drop-the-redundant-mapping-argument-of-__split_frozen_folio.patch