From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oi1-f174.google.com (mail-oi1-f174.google.com [209.85.167.174]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 18C4B489866 for ; Tue, 25 Aug 2026 15:33:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.167.174 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787671987; cv=none; b=JiZM7OZxEJbtTQ0WAbjeUrT+qWwLK2Tuh9TlnVSZjxsmgVnxyLVGY4lt2GmlvqMS/BQEhDIGwlJ/wY8SLbqmzZp+LNMi8sKl6ChgcJm6jYbRlXJuC10Z1++WFCUyx5bxQVwMecGDnCpF2iFitf42ygaOCYkqXgfIzE9a0pZMQbc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787671987; c=relaxed/simple; bh=ESa/aJb+Zcb+vI6rmyLQaTfjj0+Al0OL+w/Lgyn3Yu0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=NngPiFk0IFSVyJSlkKcK/OI9IZ+xxhFyMimvQYSaWNJCLeQWSQCS/TYzSWJPyhBp0AwWSzRTFF+rL2RZgqLpnqNj4zB2CxoirjT/uvD2+jXJIsO2AGDnuka5HeudvjeCUnJqGAtYKvhopuU6PAfIOVXPQISw5wT9YTvR4DwZPKo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=hjYysJX3; arc=none smtp.client-ip=209.85.167.174 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="hjYysJX3" Received: by mail-oi1-f174.google.com with SMTP id 5614622812f47-499f6e0bbabso4125386b6e.0 for ; Tue, 25 Aug 2026 08:33:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1787671979; x=1788276779; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to:content-type; bh=uAKqLnS2duDg8f3jGAvM1PgrDRSN4wgtQcZNf8+IpfY=; b=hjYysJX3IVpEhW0E6s0hQ6MM5lz7Gr5QgJO+Z38p3ugGbP3op1OHJorZsL+4FNXd9i Zh7DtUPcIMP+tgyQPfvAYEk1MmEANWLOSODa4hmBhshAcP4Bs6ey76yuSTLDupxwWx65 sZL53TSsyXSZAx/HrBbUtHnkkR+EsLFBYNFfezy60oc3kAvH3Bs7H5zKkdBdJeX77zbT AnquNzbPqdPllOMVV9TlcLmx0Ia1Zw+Cf+B+ApESH4qpKSTNrnbuF3OBK7kj1eODtgQU dsjfOe08atULZl9xgFqModnWExflixhwG8SPVrQoF/ffaXgxKuT6ZCGbGc/WruJJlMet TiRw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1787671979; x=1788276779; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to:content-type; bh=uAKqLnS2duDg8f3jGAvM1PgrDRSN4wgtQcZNf8+IpfY=; b=fzWYA72yyMcCsw1kTEipyRiXkz2nPffXCFpRZFuxC6EYS5DMMX7EqddjYDQgR6PiVU MlRN1qT2uT6bix49ffxZ+5rG1Z85xC6NIYWIHJA/GO2IIFwaOJJVSbwKEU+3fnjEIlvY 1khFQsqFtRI6xkwc1Mi3GwzRcFML9+Of2IOp420//uTHhZ/AGHJ3AFMbS6Q9H7Squ/nC 9vynTYFFn+GZtjH8EmBWHWx4OslHZDx4a2EtCDKFPF6tRhGw4fYWKhlvwaJCT6RTtaZr lAWzyIoz40y0rSPsEN/GznO3NGan7W41XSp78DS6Zdwq1E3vbCBffH1hukbX0ybs5Km3 o80g== X-Forwarded-Encrypted: i=1; AHgh+Rq17fryJEWLKj+oizkKuHlRSnDQUEhy6uGdC0eakTURixV24ReeaKFR3cl/9PMKDUSZi2L/vQ1Y@vger.kernel.org X-Gm-Message-State: AFuF++mMnvA3iH0MbO2PV9KaCn0QXyW40KGz3gOrV/FD2OT8xdTAfuQP pG2h3kQFk1LspUjFoK6zR2sfFU2YXYX69qINwrJDzZLtxZHVg1Jx0x+S X-Gm-Gg: AR+sD11eLYIf5OSsFXjsVltzXoXh1sZfpKBi4k3VGk0KJ6XEQoIpD4LxLXtcvJgZ/t3 Kc04zw2TKg5aD/JIFZTaO2lky0iNrmeX16ZEEcPXQaROfxswmVW2tvf3Oyt0SKPaFWisnfICxFh QuybddJMQakPGUxzZaZrpa2PZNbOM7Ou5UGXV/ZlgG4gmocUYJw/YxAbQ84meJuVe2W9nDP4xQe J5/xWvqOD7P1FSnTwTzFz9oRU9djad5voxZrRU6EOSUm6yQYnaQJ4LAMkgt58IKjt4JseG0xbMS XOIanAj/KzRIZorvzFRtxGfDekQu2cYACDet/i0tV7L8RGDweBrdufZz7ZiTs8yJA+fpY10UGAp 9HYfEjOkSwgxfApPS+d4eJEAFK3+a7dbLrQe8Y/dNMwZL2KXjGxqbo9y76pFdjYMtOd3bDBm4FA koS/kZFCBAA7R0rYwQIuq9ueEwc1UVSX8xuip9S/HGNARWfg98Aq2iqq3tg0ncSjisF2LrNV61v 56PT2o2EyE= X-Received: by 2002:a05:6808:4f49:b0:495:ff85:d33d with SMTP id 5614622812f47-4b35059a824mr7724933b6e.12.1787671978714; Tue, 25 Aug 2026 08:32:58 -0700 (PDT) Received: from localhost ([2a03:2880:10ff:28::]) by smtp.gmail.com with ESMTPSA id 5614622812f47-4b32c690f27sm5952581b6e.7.2026.08.25.08.32.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 25 Aug 2026 08:32:58 -0700 (PDT) From: Nhat Pham To: akpm@linux-foundation.org Cc: chrisl@kernel.org, kasong@tencent.com, hannes@cmpxchg.org, mhocko@kernel.org, roman.gushchin@linux.dev, shakeel.butt@linux.dev, yosry@kernel.org, david@kernel.org, muchun.song@linux.dev, shikemeng@huaweicloud.com, baoquan.he@linux.dev, baohua@kernel.org, youngjun.park@lge.com, chengming.zhou@linux.dev, ljs@kernel.org, liam@infradead.org, vbabka@kernel.org, rppt@kernel.org, surenb@google.com, qi.zheng@linux.dev, axelrasmussen@google.com, yuanchu@google.com, weixugc@google.com, riel@surriel.com, gourry@gourry.net, haowenchao22@gmail.com, corbet@lwn.net, hughd@google.com, baolin.wang@linux.alibaba.com, tj@kernel.org, mkoutny@suse.com, skhan@linuxfoundation.org, kunwu.chan@linux.dev, kernel-team@meta.com, nphamcs@gmail.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, cgroups@vger.kernel.org Subject: [PATCH v4 11/11] mm, swap: widen swap_info_struct max/pages to unsigned long Date: Tue, 25 Aug 2026 08:32:37 -0700 Message-ID: <20260825153238.2695446-12-nphamcs@gmail.com> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260825153238.2695446-1-nphamcs@gmail.com> References: <20260825153238.2695446-1-nphamcs@gmail.com> Precedence: bulk X-Mailing-List: cgroups@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Widen swap_info_struct->max and ->pages from unsigned int to unsigned long so the vswap device can exceed the previous 16 TB cap with 4 KB pages (ALIGN_DOWN(UINT_MAX, SWAPFILE_CLUSTER) pages). The new vswap cap is the cluster_info_pool xarray's allocator limit. XA_FLAGS_ALLOC stores allocated IDs in u32, so max_pages = UINT_MAX * SWAPFILE_CLUSTER (~8 PB at the typical SWAPFILE_CLUSTER=512 layout). Signed-off-by: Nhat Pham --- include/linux/swap.h | 4 +-- mm/swapfile.c | 63 ++++++++++++++++++++++---------------------- 2 files changed, 34 insertions(+), 33 deletions(-) diff --git a/include/linux/swap.h b/include/linux/swap.h index 95386a86d3fd..5310ac0f3faa 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -246,7 +246,7 @@ struct swap_info_struct { signed short prio; /* swap priority of this type */ struct plist_node list; /* entry in swap_active_head */ signed char type; /* strange name for an index */ - unsigned int max; /* size of this swap device */ + unsigned long max; /* size of this swap device */ struct swap_cluster_info *cluster_info; /* cluster info. Only for SSD */ struct list_head free_clusters; /* free clusters list */ struct list_head full_clusters; /* full clusters list */ @@ -254,7 +254,7 @@ struct swap_info_struct { /* list of cluster that contains at least one free slot */ struct list_head frag_clusters[SWAP_NR_ORDERS]; /* list of cluster that are fragmented or contented */ - unsigned int pages; /* total of usable pages of swap */ + unsigned long pages; /* total of usable pages of swap */ atomic_long_t inuse_pages; /* number of those currently in use */ struct swap_sequential_cluster *global_cluster; /* Use one global cluster for rotating device */ spinlock_t global_cluster_lock; /* Serialize usage of global cluster */ diff --git a/mm/swapfile.c b/mm/swapfile.c index 8c80544a7d25..9860fb3b079f 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -429,10 +429,10 @@ static inline unsigned int cluster_index(struct swap_info_struct *si, return ci - si->cluster_info; } -static inline unsigned int cluster_offset(struct swap_info_struct *si, - struct swap_cluster_info *ci) +static inline unsigned long cluster_offset(struct swap_info_struct *si, + struct swap_cluster_info *ci) { - return cluster_index(si, ci) * SWAPFILE_CLUSTER; + return (unsigned long)cluster_index(si, ci) * SWAPFILE_CLUSTER; } static void swap_cluster_free_table_folio_rcu_cb(struct rcu_head *head) @@ -848,7 +848,7 @@ static int swap_cluster_setup_bad_slot(struct swap_info_struct *si, /* si->max may got shrunk by swap swap_activate() */ if (offset >= si->max && !mask) { - pr_debug("Ignoring bad slot %u (max: %u)\n", offset, si->max); + pr_debug("Ignoring bad slot %u (max: %lu)\n", offset, si->max); return 0; } /* @@ -1085,13 +1085,13 @@ static bool __swap_cluster_alloc_entries(struct swap_info_struct *si, } /* Try use a new cluster for current CPU and allocate from it. */ -static unsigned int alloc_swap_scan_cluster(struct swap_info_struct *si, - struct swap_cluster_info *ci, - struct folio *folio, - unsigned long offset, - bool *nomem) +static unsigned long alloc_swap_scan_cluster(struct swap_info_struct *si, + struct swap_cluster_info *ci, + struct folio *folio, + unsigned long offset, + bool *nomem) { - unsigned int next = SWAP_ENTRY_INVALID, found = SWAP_ENTRY_INVALID; + unsigned long next = SWAP_ENTRY_INVALID, found = SWAP_ENTRY_INVALID; unsigned long start = ALIGN_DOWN(offset, SWAPFILE_CLUSTER); unsigned int order = likely(folio) ? folio_order(folio) : 0; unsigned long end = start + SWAPFILE_CLUSTER; @@ -1168,12 +1168,12 @@ static unsigned int alloc_swap_scan_cluster(struct swap_info_struct *si, return found; } -static unsigned int alloc_swap_scan_list(struct swap_info_struct *si, - struct list_head *list, - struct folio *folio, - bool scan_all) +static unsigned long alloc_swap_scan_list(struct swap_info_struct *si, + struct list_head *list, + struct folio *folio, + bool scan_all) { - unsigned int found = SWAP_ENTRY_INVALID; + unsigned long found = SWAP_ENTRY_INVALID; bool nomem = false; /* @@ -1196,8 +1196,8 @@ static unsigned int alloc_swap_scan_list(struct swap_info_struct *si, return found; } -static unsigned int vswap_alloc_cluster(struct swap_info_struct *si, - struct folio *folio) +static unsigned long vswap_alloc_cluster(struct swap_info_struct *si, + struct folio *folio) { struct swap_cluster_info_dynamic *ci_dyn; struct swap_cluster_info *ci; @@ -1324,7 +1324,7 @@ static unsigned long cluster_alloc_swap_entry(struct swap_info_struct *si, { struct swap_cluster_info *ci; unsigned int order = likely(folio) ? folio_order(folio) : 0; - unsigned int offset = SWAP_ENTRY_INVALID, found = SWAP_ENTRY_INVALID; + unsigned long offset = SWAP_ENTRY_INVALID, found = SWAP_ENTRY_INVALID; /* * Swapfile is not block device so unable @@ -3423,10 +3423,10 @@ static int unuse_mm(struct mm_struct *mm, unsigned int type) * Return 0 if there are no inuse entries after prev till end of * the map. */ -static unsigned int find_next_to_unuse(struct swap_info_struct *si, - unsigned int prev) +static unsigned long find_next_to_unuse(struct swap_info_struct *si, + unsigned long prev) { - unsigned int i; + unsigned long i; unsigned long swp_tb; /* @@ -3464,7 +3464,8 @@ static int try_to_unuse(unsigned int type) struct swap_io_ctx ctx; swp_entry_t entry, vswap_entry; unsigned long swp_tb; - unsigned int i, j; + unsigned long i; + unsigned int j; if (!swap_usage_in_pages(si)) goto success; @@ -3921,7 +3922,7 @@ SYSCALL_DEFINE1(swapoff, const char __user *, specialfile) struct file *swap_file, *victim; struct address_space *mapping; struct inode *inode; - unsigned int maxpages; + unsigned long maxpages; int err, found = 0; if (!capable(CAP_SYS_ADMIN)) @@ -4343,12 +4344,8 @@ static unsigned long read_swap_header(struct swap_info_struct *si, pr_warn("Truncating oversized swap area, only using %luk out of %luk\n", K(maxpages), K(last_page)); } - if (maxpages > last_page) { + if (maxpages > last_page) maxpages = last_page + 1; - /* p->max is an unsigned int: don't overflow it */ - if ((unsigned int)maxpages == 0) - maxpages = UINT_MAX; - } if (!maxpages) return 0; @@ -4589,7 +4586,7 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags) goto bad_swap_unlock_inode; } if (si->pages != si->max - 1) { - pr_err("swap:%u != (max:%u - 1)\n", si->pages, si->max); + pr_err("swap:%lu != (max:%lu - 1)\n", si->pages, si->max); error = -EINVAL; goto bad_swap_unlock_inode; } @@ -4677,7 +4674,7 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags) /* Sets SWP_WRITEOK, resurrect the percpu ref, expose the swap device */ enable_swap_info(si); - pr_info("Adding %uk swap on %s. Priority:%d extents:%d across:%lluk %s%s%s%s\n", + pr_info("Adding %luk swap on %s. Priority:%d extents:%d across:%lluk %s%s%s%s\n", K(si->pages), name->name, si->prio, nr_extents, K((unsigned long long)span), (si->flags & SWP_SOLIDSTATE) ? "SS" : "", @@ -4884,8 +4881,12 @@ static int __init vswap_init(void) return 0; } + /* + * One u32 xarray ID per cluster, so the device cannot be larger + * than UINT_MAX clusters. + */ maxpages = min(swapfile_maximum_size, - ALIGN_DOWN((unsigned long)UINT_MAX, SWAPFILE_CLUSTER)); + (unsigned long)UINT_MAX * SWAPFILE_CLUSTER); /* * SWP_WRITEOK enables slot allocation. SWP_SOLIDSTATE selects * per-CPU cluster allocation; vswap has no si->global_cluster. -- 2.53.0-Meta