From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 B52DD1D516C for ; Fri, 20 Feb 2026 00:36:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771547806; cv=none; b=ei2DqcRAvk4QF9U9sjVTwxQijiDmPHqjCGvpcboKKQIL0J+MsyAe+tndBQBgyzhxtAGSwDxAOeOo7QPH4Q3R3e/ew6TvEiUK5IXbGqsQYPWWiExntNfLf30NzxqdJyYjx/VzFq8FLLmSTSzs1VpcHsXOMZjoy9A9EBlvq42B8KQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771547806; c=relaxed/simple; bh=w8+DaqgvKIc5D5rS8OP2vFRjpfV8tg9RzEtxPftB6no=; h=Date:To:From:Subject:Message-Id; b=dpiA1H6OIk597QR6nnAGCOcwArquO2U79KFpxdHrAKQ8qT3PWPcFFg+wMzc7Hcl+KKQUIIW+9WzGAns8ktZFmkBOtJ+yYgAsMrLW3MOaykNBrrdfrLAq7+LbWiMZKBEj3ICTfMJ42qEA2kI/jIQoch/Rk4Ta8OTizsk8rRhnyP4= 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=gxiuo37i; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="gxiuo37i" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8352DC4CEF7; Fri, 20 Feb 2026 00:36:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1771547806; bh=w8+DaqgvKIc5D5rS8OP2vFRjpfV8tg9RzEtxPftB6no=; h=Date:To:From:Subject:From; b=gxiuo37iKcoi4+aXoqheQETAZzpHzmoVSNAUiepXN2jhNd68vgTytRljbtfNYKNjW CRXWUnylQUQ4xWKEDKgVqUEcWguCtblDMwIEBeHeNI4gc0oInTEMZLPLcBFZWsVz73 FDbysZuJ786Ta1/FVZkb1pjlh4zE71FElBpSEq8Q= Date: Thu, 19 Feb 2026 16:36:46 -0800 To: mm-commits@vger.kernel.org,shikemeng@huaweicloud.com,ryncsn@gmail.com,nphamcs@gmail.com,lorenzo.stoakes@oracle.com,lkp@intel.com,hannes@cmpxchg.org,david@kernel.org,chrisl@kernel.org,bhe@redhat.com,baohua@kernel.org,kasong@tencent.com,akpm@linux-foundation.org From: Andrew Morton Subject: + mm-swap-simplify-swap-table-sanity-range-check.patch added to mm-new branch Message-Id: <20260220003646.8352DC4CEF7@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: mm, swap: simplify swap table sanity range check has been added to the -mm mm-new branch. Its filename is mm-swap-simplify-swap-table-sanity-range-check.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-swap-simplify-swap-table-sanity-range-check.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 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, swap: simplify swap table sanity range check Date: Wed, 18 Feb 2026 04:06:33 +0800 The newly introduced helper, which checks bad slots and emptiness of a cluster, can cover the older sanity check just fine, with a more rigorous condition check. So merge them. Link: https://lkml.kernel.org/r/20260218-swap-table-p3-v3-8-f4e34be021a7@tencent.com Signed-off-by: Kairui Song Acked-by: Chris Li Cc: Baoquan He Cc: Barry Song Cc: David Hildenbrand Cc: Johannes Weiner Cc: Kairui Song Cc: Kemeng Shi Cc: kernel test robot Cc: Lorenzo Stoakes Cc: Nhat Pham Signed-off-by: Andrew Morton --- mm/swapfile.c | 35 +++++++++-------------------------- 1 file changed, 9 insertions(+), 26 deletions(-) --- a/mm/swapfile.c~mm-swap-simplify-swap-table-sanity-range-check +++ a/mm/swapfile.c @@ -459,9 +459,11 @@ static void swap_table_free(struct swap_ * One special case is that bad slots can't be freed, so check the number of * bad slots for swapoff, and non-swapoff path must never free bad slots. */ -static void swap_cluster_assert_empty(struct swap_cluster_info *ci, bool swapoff) +static void swap_cluster_assert_empty(struct swap_cluster_info *ci, + unsigned int ci_off, unsigned int nr, + bool swapoff) { - unsigned int ci_off = 0, ci_end = SWAPFILE_CLUSTER; + unsigned int ci_end = ci_off + nr; unsigned long swp_tb; int bad_slots = 0; @@ -588,7 +590,7 @@ static void swap_cluster_schedule_discar static void __free_cluster(struct swap_info_struct *si, struct swap_cluster_info *ci) { - swap_cluster_assert_empty(ci, false); + swap_cluster_assert_empty(ci, 0, SWAPFILE_CLUSTER, false); swap_cluster_free_table(ci); move_cluster(si, ci, &si->free_clusters, CLUSTER_FLAG_FREE); ci->order = 0; @@ -898,26 +900,6 @@ static bool cluster_scan_range(struct sw return true; } -/* - * Currently, the swap table is not used for count tracking, just - * do a sanity check here to ensure nothing leaked, so the swap - * table should be empty upon freeing. - */ -static void swap_cluster_assert_table_empty(struct swap_cluster_info *ci, - unsigned int start, unsigned int nr) -{ - unsigned int ci_off = start % SWAPFILE_CLUSTER; - unsigned int ci_end = ci_off + nr; - unsigned long swp_tb; - - if (IS_ENABLED(CONFIG_DEBUG_VM)) { - do { - swp_tb = __swap_table_get(ci, ci_off); - VM_WARN_ON_ONCE(!swp_tb_is_null(swp_tb)); - } while (++ci_off < ci_end); - } -} - static bool cluster_alloc_range(struct swap_info_struct *si, struct swap_cluster_info *ci, struct folio *folio, @@ -943,13 +925,14 @@ static bool cluster_alloc_range(struct s if (likely(folio)) { order = folio_order(folio); nr_pages = 1 << order; + swap_cluster_assert_empty(ci, offset % SWAPFILE_CLUSTER, nr_pages, false); __swap_cache_add_folio(ci, folio, swp_entry(si->type, offset)); } else if (IS_ENABLED(CONFIG_HIBERNATION)) { order = 0; nr_pages = 1; WARN_ON_ONCE(si->swap_map[offset]); si->swap_map[offset] = 1; - swap_cluster_assert_table_empty(ci, offset, 1); + swap_cluster_assert_empty(ci, offset % SWAPFILE_CLUSTER, 1, false); } else { /* Allocation without folio is only possible with hibernation */ WARN_ON_ONCE(1); @@ -1768,7 +1751,7 @@ void swap_entries_free(struct swap_info_ mem_cgroup_uncharge_swap(entry, nr_pages); swap_range_free(si, offset, nr_pages); - swap_cluster_assert_table_empty(ci, offset, nr_pages); + swap_cluster_assert_empty(ci, offset % SWAPFILE_CLUSTER, nr_pages, false); if (!ci->count) free_cluster(si, ci); @@ -2780,7 +2763,7 @@ static void free_swap_cluster_info(struc /* Cluster with bad marks count will have a remaining table */ spin_lock(&ci->lock); if (rcu_dereference_protected(ci->table, true)) { - swap_cluster_assert_empty(ci, true); + swap_cluster_assert_empty(ci, 0, SWAPFILE_CLUSTER, true); swap_cluster_free_table(ci); } spin_unlock(&ci->lock); _ Patches currently in -mm which might be from kasong@tencent.com are mm-swap-speed-up-hibernation-allocation-and-writeout.patch mm-swap-protect-si-swap_file-properly-and-use-as-a-mount-indicator.patch mm-swap-clean-up-swapon-process-and-locking.patch mm-swap-remove-redundant-arguments-and-locking-for-enabling-a-device.patch mm-swap-consolidate-bad-slots-setup-and-make-it-more-robust.patch mm-workingset-leave-highest-bits-empty-for-anon-shadow.patch mm-swap-implement-helpers-for-reserving-data-in-the-swap-table.patch mm-swap-mark-bad-slots-in-swap-table-directly.patch mm-swap-simplify-swap-table-sanity-range-check.patch mm-swap-use-the-swap-table-to-track-the-swap-count.patch mm-swap-no-need-to-truncate-the-scan-border.patch mm-swap-simplify-checking-if-a-folio-is-swapped.patch mm-swap-no-need-to-clear-the-shadow-explicitly.patch