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 9F246469852 for ; Wed, 23 Sep 2026 22:32:44 +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=1790202766; cv=none; b=rGA76iA1HpF6BGe+dThghZi83YD6rPyfRUa4nMocVOyk1oIo2Bssps7Jnq5aQgmYuYu+eYG0Sr7q9AVExnN1vMwqvPlrn9F97Q68nSnJLNaiStaMuFiHp+1zrR70vYisiamRGGPh3xn74RDP6ZMP4QqISLh2I5yjcwifyhyHmEs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790202766; c=relaxed/simple; bh=xxdXA4UH19wmsnc3raXWgZ+CtdsY9meR2KqjZZUARkg=; h=Date:To:From:Subject:Message-Id; b=qkMwjrh0d7ZPKC0V2pVNpJwjlWbJrekxCsrNKc6/3qHvF5XnhHIjPzwyRSX7NaLcOOiLcOlgOgj+1GaqyYYEbLOwnfSis56/FZ4N1/rS9MxKv+RmxQ+W3g/7cktAvhm5L92b4EUiQbtMsM81HYWi9GHlTyV2S35t5tDW9M1Ln/8= 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=jQAnEK/y; 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="jQAnEK/y" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 39F6B1F00898; Wed, 23 Sep 2026 22:32:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1790202764; bh=Cpb3HH/di+L2fuBeU0KJG4etCRfsG0qquA8U6e70qZs=; h=Date:To:From:Subject; b=jQAnEK/ypgiKWukr1/ws+cTXOuQr2Xwf1CPhg1v04hHgpZe7Mc4+erQHK2oopmC17 P+FBv/viWjxxTv1ZwqZWKgcXc3LqlQIugUitns6P6T+43qgncDYjX8gfzEuW6dWI0s iMkIieM0CrJpz4XwyrbFUk7fM1I79delabUJbu+g= Date: Wed, 23 Sep 2026 15:32:43 -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-unstable branch Message-Id: <20260923223244.39F6B1F00898@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-unstable 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-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm 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: Wed, 23 Sep 2026 23:32:42 +0200 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/20260923-swap-thp-cleanup-v6-11-ba1b4ba72c6f@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 Acked-by: David Hildenbrand (Arm) Cc: Lorenzo Stoakes Cc: Baolin Wang Cc: Liam R. Howlett Cc: Nico Pache Cc: Ryan Roberts Cc: Dev Jain Cc: Lance Yang Cc: Usama Arif Cc: Vlastimil Babka Cc: Mike Rapoport Cc: Suren Baghdasaryan Cc: Michal Hocko Cc: Chris Li Cc: Kemeng Shi Cc: Nhat Pham Cc: Baoquan He Cc: Barry Song Cc: Youngjun Park Cc: Shivam Kalra Cc: Kairui Song --- 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 @@ -4110,16 +4110,42 @@ 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) { + const 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); @@ -4137,15 +4163,15 @@ 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; } @@ -4172,7 +4198,7 @@ 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); /* @@ -4224,9 +4250,19 @@ static int __folio_freeze_split_file(str if (do_lru) lruvec_unlock(lruvec); fail: - 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; } @@ -4255,11 +4291,9 @@ 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; @@ -4306,61 +4340,16 @@ 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. */ @@ -4383,14 +4372,11 @@ 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