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 9C65A2C11CA for ; Tue, 15 Sep 2026 00:45:20 +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=1789433122; cv=none; b=g1QYkxPeb4lSGhLqnIwmbiHwY4cg5A5maqPXhpHvqnwUHgzrYtRnGrLcaD3WpZkcQwPFz533Dm0eZTZ8exJ7dwJs1fEtWdqzDTMZg6EhYfUwr6YiVgqqkv5NulfShSfyaEWPoH30r5lMXi1CSzZVrO2wTS9LT1QKSXA9sZWTtAg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789433122; c=relaxed/simple; bh=p87DNy2QTwSBbYZFY+L7w5DwXmOxcVpc8xcgCsN+/WQ=; h=Date:To:From:Subject:Message-Id; b=FuQ2OH9IUznTB/XgzKnPVmuFoI8mc1o1H99lJ+CmZMGpOM3T4s4HPxKDJY4KvsHSUNaJ9t8Tqt3LwoP/EAcr+uoJgPfyCg22QOfIOoZc85wKDrUL2l8JHE+Xjl0hhOjIozFQoK3EYXgwfJdSPe50CLQqtdx60apj4LSl0F6wqo0= 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=hH0MjrJp; 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="hH0MjrJp" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E408B1F00893; Tue, 15 Sep 2026 00:45:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1789433120; bh=QynGr4ZaIP58xQYyKYlcGI5xzK2BlEK2SOjzY5AdSoY=; h=Date:To:From:Subject; b=hH0MjrJpj0Eh90wEhFFJRhtOhryWcYoEwSCCbQvv0uqwmiJeVG7GrgriFpFpV3yEN fPFYbEAmLW2+EXdLIrw48+d65jsBZFoHvp9fLg3E/faXZhd6E3aOwhxaplzmSxpBoq TwVU6WCOzzbAwW7ped0cF/SVnN2k2/rk91PM2Css= Date: Mon, 14 Sep 2026 17:45:19 -0700 To: mm-commits@vger.kernel.org,kasong@tencent.com,akpm@linux-foundation.org From: Andrew Morton Subject: + mm-huge_memory-move-memcg-switch-into-the-file-split-helper.patch added to mm-new branch Message-Id: <20260915004519.E408B1F00893@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 memcg switch into the file split helper has been added to the -mm mm-new branch. Its filename is mm-huge_memory-move-memcg-switch-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-memcg-switch-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 memcg switch into the file split helper Date: Tue, 15 Sep 2026 01:14:54 +0800 The xarray node allocations in __folio_freeze_split_file() need to be charged to the folio's memcg, so move the memcg switch from __folio_split() into the helper. The anon split helper and the after-split folio freeing perform no chargeable allocations, so no memcg handling is left in __folio_split(). Rename its out_no_memcg label to out. Link: https://lore.kernel.org/20260915-swap-thp-cleanup-v5-13-39878b37dfb0@tencent.com Signed-off-by: Kairui Song Signed-off-by: Andrew Morton Acked-by: Zi Yan Acked-by: David Hildenbrand (Arm) Reviewed-by: Yeoreum Yun Reviewed-by: Kiryl Shutsemau (Meta) Cc: Baolin Wang Cc: Baoquan He Cc: Barry Song Cc: Chris Li 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 | 36 +++++++++++++++++++----------------- 1 file changed, 19 insertions(+), 17 deletions(-) --- a/mm/huge_memory.c~mm-huge_memory-move-memcg-switch-into-the-file-split-helper +++ a/mm/huge_memory.c @@ -4140,6 +4140,7 @@ static int __folio_freeze_split_file(str struct address_space *mapping = folio->mapping; XA_STATE(xas, &mapping->i_pages, folio->index); struct folio *end_folio = folio_next(folio); + struct mem_cgroup *memcg, *old_memcg; struct folio *new_folio, *next; int nr_shmem_dropped = 0; unsigned int min_order; @@ -4152,9 +4153,18 @@ static int __folio_freeze_split_file(str if (new_order < min_order) return -EINVAL; + /* + * Switch to folio's memcg as xarray node allocation can happen and + * needs to charge to it. + */ + memcg = get_mem_cgroup_from_folio(folio); + old_memcg = set_active_memcg(memcg); + gfp = current_gfp_context(mapping_gfp_mask(mapping) & GFP_RECLAIM_MASK); - if (!filemap_release_folio(folio, gfp)) - return -EBUSY; + if (!filemap_release_folio(folio, gfp)) { + ret = -EBUSY; + goto fail_free; + } mapping_set_update(&xas, mapping); @@ -4290,6 +4300,9 @@ fail_mmap_unlock: */ i_mmap_unlock_read(mapping); fail_free: + /* Restore the previously active memcg */ + set_active_memcg(old_memcg); + mem_cgroup_put(memcg); xas_destroy(&xas); return ret; } @@ -4321,7 +4334,6 @@ static int __folio_split(struct folio *f { struct folio *end_folio = folio_next(folio); bool is_anon = folio_test_anon(folio); - struct mem_cgroup *memcg, *old_memcg; int old_order = folio_order(folio); struct folio *new_folio, *next; int ret; @@ -4331,27 +4343,20 @@ static int __folio_split(struct folio *f if (folio != page_folio(split_at) || folio != page_folio(lock_at)) { ret = -EINVAL; - goto out_no_memcg; + goto out; } if (new_order >= old_order) { ret = -EINVAL; - goto out_no_memcg; + goto out; } ret = folio_check_splittable(folio, new_order, split_type); if (ret) { VM_WARN_ONCE(ret == -EINVAL, "Tried to split an unsplittable folio"); - goto out_no_memcg; + goto out; } - /* - * switch to folio's memcg as xarray node allocation can happen and - * needs to charge to it. - */ - memcg = get_mem_cgroup_from_folio(folio); - old_memcg = set_active_memcg(memcg); - if (is_anon) ret = __folio_freeze_split_anon(folio, new_order, split_at, true, list, split_type); @@ -4378,10 +4383,7 @@ static int __folio_split(struct folio *f free_folio_and_swap_cache(new_folio); } - /* restore to caller's old_memcg */ - set_active_memcg(old_memcg); - mem_cgroup_put(memcg); -out_no_memcg: +out: 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