Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted

Pull networking updates from Jakub Kicinski:
 "Core:

   - Add dedicated kmem_cache for typical/small skb->head, avoid having
     to access struct page at kfree time, and improve memory use.

   - Introduce sysctl to set default RPS configuration for new netdevs.

   - Define Netlink protocol specification format which can be used to
     describe messages used by each family and auto-generate parsers.
     Add tools for generating kernel data structures and uAPI headers.

   - Expose all net/core sysctls inside netns.

   - Remove 4s sleep in netpoll if carrier is instantly detected on
     boot.

   - Add configurable limit of MDB entries per port, and port-vlan.

   - Continue populating drop reasons throughout the stack.

   - Retire a handful of legacy Qdiscs and classifiers.

  Protocols:

   - Support IPv4 big TCP (TSO frames larger than 64kB).

   - Add IP_LOCAL_PORT_RANGE socket option, to control local port range
     on socket by socket basis.

   - Track and report in procfs number of MPTCP sockets used.

   - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path
     manager.

   - IPv6: don't check net.ipv6.route.max_size and rely on garbage
     collection to free memory (similarly to IPv4).

   - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986).

   - ICMP: add per-rate limit counters.

   - Add support for user scanning requests in ieee802154.

   - Remove static WEP support.

   - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate
     reporting.

   - WiFi 7 EHT channel puncturing support (client & AP).

  BPF:

   - Add a rbtree data structure following the "next-gen data structure"
     precedent set by recently added linked list, that is, by using
     kfunc + kptr instead of adding a new BPF map type.

   - Expose XDP hints via kfuncs with initial support for RX hash and
     timestamp metadata.

   - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to
     better support decap on GRE tunnel devices not operating in collect
     metadata.

   - Improve x86 JIT's codegen for PROBE_MEM runtime error checks.

   - Remove the need for trace_printk_lock for bpf_trace_printk and
     bpf_trace_vprintk helpers.

   - Extend libbpf's bpf_tracing.h support for tracing arguments of
     kprobes/uprobes and syscall as a special case.

   - Significantly reduce the search time for module symbols by
     livepatch and BPF.

   - Enable cpumasks to be used as kptrs, which is useful for tracing
     programs tracking which tasks end up running on which CPUs in
     different time intervals.

   - Add support for BPF trampoline on s390x and riscv64.

   - Add capability to export the XDP features supported by the NIC.

   - Add __bpf_kfunc tag for marking kernel functions as kfuncs.

   - Add cgroup.memory=nobpf kernel parameter option to disable BPF
     memory accounting for container environments.

  Netfilter:

   - Remove the CLUSTERIP target. It has been marked as obsolete for
     years, and we still have WARN splats wrt races of the out-of-band
     /proc interface installed by this target.

   - Add 'destroy' commands to nf_tables. They are identical to the
     existing 'delete' commands, but do not return an error if the
     referenced object (set, chain, rule...) did not exist.

  Driver API:

   - Improve cpumask_local_spread() locality to help NICs set the right
     IRQ affinity on AMD platforms.

   - Separate C22 and C45 MDIO bus transactions more clearly.

   - Introduce new DCB table to control DSCP rewrite on egress.

   - Support configuration of Physical Layer Collision Avoidance (PLCA)
     Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of
     shared medium Ethernet.

   - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing
     preemption of low priority frames by high priority frames.

   - Add support for controlling MACSec offload using netlink SET.

   - Rework devlink instance refcounts to allow registration and
     de-registration under the instance lock. Split the code into
     multiple files, drop some of the unnecessarily granular locks and
     factor out common parts of netlink operation handling.

   - Add TX frame aggregation parameters (for USB drivers).

   - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning
     messages with notifications for debug.

   - Allow offloading of UDP NEW connections via act_ct.

   - Add support for per action HW stats in TC.

   - Support hardware miss to TC action (continue processing in SW from
     a specific point in the action chain).

   - Warn if old Wireless Extension user space interface is used with
     modern cfg80211/mac80211 drivers. Do not support Wireless
     Extensions for Wi-Fi 7 devices at all. Everyone should switch to
     using nl80211 interface instead.

   - Improve the CAN bit timing configuration. Use extack to return
     error messages directly to user space, update the SJW handling,
     including the definition of a new default value that will benefit
     CAN-FD controllers, by increasing their oscillator tolerance.

  New hardware / drivers:

   - Ethernet:
      - nVidia BlueField-3 support (control traffic driver)
      - Ethernet support for imx93 SoCs
      - Motorcomm yt8531 gigabit Ethernet PHY
      - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA)
      - Microchip LAN8841 PHY (incl. cable diagnostics and PTP)
      - Amlogic gxl MDIO mux

   - WiFi:
      - RealTek RTL8188EU (rtl8xxxu)
      - Qualcomm Wi-Fi 7 devices (ath12k)

   - CAN:
      - Renesas R-Car V4H

  Drivers:

   - Bluetooth:
      - Set Per Platform Antenna Gain (PPAG) for Intel controllers.

   - Ethernet NICs:
      - Intel (1G, igc):
         - support TSN / Qbv / packet scheduling features of i226 model
      - Intel (100G, ice):
         - use GNSS subsystem instead of TTY
         - multi-buffer XDP support
         - extend support for GPIO pins to E823 devices
      - nVidia/Mellanox:
         - update the shared buffer configuration on PFC commands
         - implement PTP adjphase function for HW offset control
         - TC support for Geneve and GRE with VF tunnel offload
         - more efficient crypto key management method
         - multi-port eswitch support
      - Netronome/Corigine:
         - add DCB IEEE support
         - support IPsec offloading for NFP3800
      - Freescale/NXP (enetc):
         - support XDP_REDIRECT for XDP non-linear buffers
         - improve reconfig, avoid link flap and waiting for idle
         - support MAC Merge layer
      - Other NICs:
         - sfc/ef100: add basic devlink support for ef100
         - ionic: rx_push mode operation (writing descriptors via MMIO)
         - bnxt: use the auxiliary bus abstraction for RDMA
         - r8169: disable ASPM and reset bus in case of tx timeout
         - cpsw: support QSGMII mode for J721e CPSW9G
         - cpts: support pulse-per-second output
         - ngbe: add an mdio bus driver
         - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing
         - r8152: handle devices with FW with NCM support
         - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation
         - virtio-net: support multi buffer XDP
         - virtio/vsock: replace virtio_vsock_pkt with sk_buff
         - tsnep: XDP support

   - Ethernet high-speed switches:
      - nVidia/Mellanox (mlxsw):
         - add support for latency TLV (in FW control messages)
      - Microchip (sparx5):
         - separate explicit and implicit traffic forwarding rules, make
           the implicit rules always active
         - add support for egress DSCP rewrite
         - IS0 VCAP support (Ingress Classification)
         - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS
           etc.)
         - ES2 VCAP support (Egress Access Control)
         - support for Per-Stream Filtering and Policing (802.1Q,
           8.6.5.1)

   - Ethernet embedded switches:
      - Marvell (mv88e6xxx):
         - add MAB (port auth) offload support
         - enable PTP receive for mv88e6390
      - NXP (ocelot):
         - support MAC Merge layer
         - support for the the vsc7512 internal copper phys
      - Microchip:
         - lan9303: convert to PHYLINK
         - lan966x: support TC flower filter statistics
         - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x
         - lan937x: support Credit Based Shaper configuration
         - ksz9477: support Energy Efficient Ethernet
      - other:
         - qca8k: convert to regmap read/write API, use bulk operations
         - rswitch: Improve TX timestamp accuracy

   - Intel WiFi (iwlwifi):
      - EHT (Wi-Fi 7) rate reporting
      - STEP equalizer support: transfer some STEP (connection to radio
        on platforms with integrated wifi) related parameters from the
        BIOS to the firmware.

   - Qualcomm 802.11ax WiFi (ath11k):
      - IPQ5018 support
      - Fine Timing Measurement (FTM) responder role support
      - channel 177 support

   - MediaTek WiFi (mt76):
      - per-PHY LED support
      - mt7996: EHT (Wi-Fi 7) support
      - Wireless Ethernet Dispatch (WED) reset support
      - switch to using page pool allocator

   - RealTek WiFi (rtw89):
      - support new version of Bluetooth co-existance

   - Mobile:
      - rmnet: support TX aggregation"

* tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits)
  page_pool: add a comment explaining the fragment counter usage
  net: ethtool: fix __ethtool_dev_mm_supported() implementation
  ethtool: pse-pd: Fix double word in comments
  xsk: add linux/vmalloc.h to xsk.c
  sefltests: netdevsim: wait for devlink instance after netns removal
  selftest: fib_tests: Always cleanup before exit
  net/mlx5e: Align IPsec ASO result memory to be as required by hardware
  net/mlx5e: TC, Set CT miss to the specific ct action instance
  net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG
  net/mlx5: Refactor tc miss handling to a single function
  net/mlx5: Kconfig: Make tc offload depend on tc skb extension
  net/sched: flower: Support hardware miss to tc action
  net/sched: flower: Move filter handle initialization earlier
  net/sched: cls_api: Support hardware miss to tc action
  net/sched: Rename user cookie and act cookie
  sfc: fix builds without CONFIG_RTC_LIB
  sfc: clean up some inconsistent indentings
  net/mlx4_en: Introduce flexible array to silence overflow warning
  net: lan966x: Fix possible deadlock inside PTP
  net/ulp: Remove redundant ->clone() test in inet_clone_ulp().
  ...

1 files changed, 1118 insertions, 0 deletions

diff --git a/mm/swap.c b/mm/swap.c
new file mode 100644
index 000000000..4c03ecab6
--- /dev/null
+++ b/mm/swap.c
@@ -0,0 +1,1118 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  linux/mm/swap.c
+ *
+ *  Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
+ */
+
+/*
+ * This file contains the default values for the operation of the
+ * Linux VM subsystem. Fine-tuning documentation can be found in
+ * Documentation/admin-guide/sysctl/vm.rst.
+ * Started 18.12.91
+ * Swap aging added 23.2.95, Stephen Tweedie.
+ * Buffermem limits added 12.3.98, Rik van Riel.
+ */
+
+#include <linux/mm.h>
+#include <linux/sched.h>
+#include <linux/kernel_stat.h>
+#include <linux/swap.h>
+#include <linux/mman.h>
+#include <linux/pagemap.h>
+#include <linux/pagevec.h>
+#include <linux/init.h>
+#include <linux/export.h>
+#include <linux/mm_inline.h>
+#include <linux/percpu_counter.h>
+#include <linux/memremap.h>
+#include <linux/percpu.h>
+#include <linux/cpu.h>
+#include <linux/notifier.h>
+#include <linux/backing-dev.h>
+#include <linux/memcontrol.h>
+#include <linux/gfp.h>
+#include <linux/uio.h>
+#include <linux/hugetlb.h>
+#include <linux/page_idle.h>
+#include <linux/local_lock.h>
+#include <linux/buffer_head.h>
+
+#include "internal.h"
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/pagemap.h>
+
+/* How many pages do we try to swap or page in/out together? As a power of 2 */
+int page_cluster;
+const int page_cluster_max = 31;
+
+/* Protecting only lru_rotate.fbatch which requires disabling interrupts */
+struct lru_rotate {
+	local_lock_t lock;
+	struct folio_batch fbatch;
+};
+static DEFINE_PER_CPU(struct lru_rotate, lru_rotate) = {
+	.lock = INIT_LOCAL_LOCK(lock),
+};
+
+/*
+ * The following folio batches are grouped together because they are protected
+ * by disabling preemption (and interrupts remain enabled).
+ */
+struct cpu_fbatches {
+	local_lock_t lock;
+	struct folio_batch lru_add;
+	struct folio_batch lru_deactivate_file;
+	struct folio_batch lru_deactivate;
+	struct folio_batch lru_lazyfree;
+#ifdef CONFIG_SMP
+	struct folio_batch activate;
+#endif
+};
+static DEFINE_PER_CPU(struct cpu_fbatches, cpu_fbatches) = {
+	.lock = INIT_LOCAL_LOCK(lock),
+};
+
+/*
+ * This path almost never happens for VM activity - pages are normally freed
+ * via pagevecs.  But it gets used by networking - and for compound pages.
+ */
+static void __page_cache_release(struct folio *folio)
+{
+	if (folio_test_lru(folio)) {
+		struct lruvec *lruvec;
+		unsigned long flags;
+
+		lruvec = folio_lruvec_lock_irqsave(folio, &flags);
+		lruvec_del_folio(lruvec, folio);
+		__folio_clear_lru_flags(folio);
+		unlock_page_lruvec_irqrestore(lruvec, flags);
+	}
+	/* See comment on folio_test_mlocked in release_pages() */
+	if (unlikely(folio_test_mlocked(folio))) {
+		long nr_pages = folio_nr_pages(folio);
+
+		__folio_clear_mlocked(folio);
+		zone_stat_mod_folio(folio, NR_MLOCK, -nr_pages);
+		count_vm_events(UNEVICTABLE_PGCLEARED, nr_pages);
+	}
+}
+
+static void __folio_put_small(struct folio *folio)
+{
+	__page_cache_release(folio);
+	mem_cgroup_uncharge(folio);
+	free_unref_page(&folio->page, 0);
+}
+
+static void __folio_put_large(struct folio *folio)
+{
+	/*
+	 * __page_cache_release() is supposed to be called for thp, not for
+	 * hugetlb. This is because hugetlb page does never have PageLRU set
+	 * (it's never listed to any LRU lists) and no memcg routines should
+	 * be called for hugetlb (it has a separate hugetlb_cgroup.)
+	 */
+	if (!folio_test_hugetlb(folio))
+		__page_cache_release(folio);
+	destroy_large_folio(folio);
+}
+
+void __folio_put(struct folio *folio)
+{
+	if (unlikely(folio_is_zone_device(folio)))
+		free_zone_device_page(&folio->page);
+	else if (unlikely(folio_test_large(folio)))
+		__folio_put_large(folio);
+	else
+		__folio_put_small(folio);
+}
+EXPORT_SYMBOL(__folio_put);
+
+/**
+ * put_pages_list() - release a list of pages
+ * @pages: list of pages threaded on page->lru
+ *
+ * Release a list of pages which are strung together on page.lru.
+ */
+void put_pages_list(struct list_head *pages)
+{
+	struct folio *folio, *next;
+
+	list_for_each_entry_safe(folio, next, pages, lru) {
+		if (!folio_put_testzero(folio)) {
+			list_del(&folio->lru);
+			continue;
+		}
+		if (folio_test_large(folio)) {
+			list_del(&folio->lru);
+			__folio_put_large(folio);
+			continue;
+		}
+		/* LRU flag must be clear because it's passed using the lru */
+	}
+
+	free_unref_page_list(pages);
+	INIT_LIST_HEAD(pages);
+}
+EXPORT_SYMBOL(put_pages_list);
+
+typedef void (*move_fn_t)(struct lruvec *lruvec, struct folio *folio);
+
+static void lru_add_fn(struct lruvec *lruvec, struct folio *folio)
+{
+	int was_unevictable = folio_test_clear_unevictable(folio);
+	long nr_pages = folio_nr_pages(folio);
+
+	VM_BUG_ON_FOLIO(folio_test_lru(folio), folio);
+
+	/*
+	 * Is an smp_mb__after_atomic() still required here, before
+	 * folio_evictable() tests the mlocked flag, to rule out the possibility
+	 * of stranding an evictable folio on an unevictable LRU?  I think
+	 * not, because __munlock_page() only clears the mlocked flag
+	 * while the LRU lock is held.
+	 *
+	 * (That is not true of __page_cache_release(), and not necessarily
+	 * true of release_pages(): but those only clear the mlocked flag after
+	 * folio_put_testzero() has excluded any other users of the folio.)
+	 */
+	if (folio_evictable(folio)) {
+		if (was_unevictable)
+			__count_vm_events(UNEVICTABLE_PGRESCUED, nr_pages);
+	} else {
+		folio_clear_active(folio);
+		folio_set_unevictable(folio);
+		/*
+		 * folio->mlock_count = !!folio_test_mlocked(folio)?
+		 * But that leaves __mlock_page() in doubt whether another
+		 * actor has already counted the mlock or not.  Err on the
+		 * safe side, underestimate, let page reclaim fix it, rather
+		 * than leaving a page on the unevictable LRU indefinitely.
+		 */
+		folio->mlock_count = 0;
+		if (!was_unevictable)
+			__count_vm_events(UNEVICTABLE_PGCULLED, nr_pages);
+	}
+
+	lruvec_add_folio(lruvec, folio);
+	trace_mm_lru_insertion(folio);
+}
+
+static void folio_batch_move_lru(struct folio_batch *fbatch, move_fn_t move_fn)
+{
+	int i;
+	struct lruvec *lruvec = NULL;
+	unsigned long flags = 0;
+
+	for (i = 0; i < folio_batch_count(fbatch); i++) {
+		struct folio *folio = fbatch->folios[i];
+
+		/* block memcg migration while the folio moves between lru */
+		if (move_fn != lru_add_fn && !folio_test_clear_lru(folio))
+			continue;
+
+		lruvec = folio_lruvec_relock_irqsave(folio, lruvec, &flags);
+		move_fn(lruvec, folio);
+
+		folio_set_lru(folio);
+	}
+
+	if (lruvec)
+		unlock_page_lruvec_irqrestore(lruvec, flags);
+	folios_put(fbatch->folios, folio_batch_count(fbatch));
+	folio_batch_init(fbatch);
+}
+
+static void folio_batch_add_and_move(struct folio_batch *fbatch,
+		struct folio *folio, move_fn_t move_fn)
+{
+	if (folio_batch_add(fbatch, folio) && !folio_test_large(folio) &&
+	    !lru_cache_disabled())
+		return;
+	folio_batch_move_lru(fbatch, move_fn);
+}
+
+static void lru_move_tail_fn(struct lruvec *lruvec, struct folio *folio)
+{
+	if (!folio_test_unevictable(folio)) {
+		lruvec_del_folio(lruvec, folio);
+		folio_clear_active(folio);
+		lruvec_add_folio_tail(lruvec, folio);
+		__count_vm_events(PGROTATED, folio_nr_pages(folio));
+	}
+}
+
+/*
+ * Writeback is about to end against a folio which has been marked for
+ * immediate reclaim.  If it still appears to be reclaimable, move it
+ * to the tail of the inactive list.
+ *
+ * folio_rotate_reclaimable() must disable IRQs, to prevent nasty races.
+ */
+void folio_rotate_reclaimable(struct folio *folio)
+{
+	if (!folio_test_locked(folio) && !folio_test_dirty(folio) &&
+	    !folio_test_unevictable(folio) && folio_test_lru(folio)) {
+		struct folio_batch *fbatch;
+		unsigned long flags;
+
+		folio_get(folio);
+		local_lock_irqsave(&lru_rotate.lock, flags);
+		fbatch = this_cpu_ptr(&lru_rotate.fbatch);
+		folio_batch_add_and_move(fbatch, folio, lru_move_tail_fn);
+		local_unlock_irqrestore(&lru_rotate.lock, flags);
+	}
+}
+
+void lru_note_cost(struct lruvec *lruvec, bool file,
+		   unsigned int nr_io, unsigned int nr_rotated)
+{
+	unsigned long cost;
+
+	/*
+	 * Reflect the relative cost of incurring IO and spending CPU
+	 * time on rotations. This doesn't attempt to make a precise
+	 * comparison, it just says: if reloads are about comparable
+	 * between the LRU lists, or rotations are overwhelmingly
+	 * different between them, adjust scan balance for CPU work.
+	 */
+	cost = nr_io * SWAP_CLUSTER_MAX + nr_rotated;
+
+	do {
+		unsigned long lrusize;
+
+		/*
+		 * Hold lruvec->lru_lock is safe here, since
+		 * 1) The pinned lruvec in reclaim, or
+		 * 2) From a pre-LRU page during refault (which also holds the
+		 *    rcu lock, so would be safe even if the page was on the LRU
+		 *    and could move simultaneously to a new lruvec).
+		 */
+		spin_lock_irq(&lruvec->lru_lock);
+		/* Record cost event */
+		if (file)
+			lruvec->file_cost += cost;
+		else
+			lruvec->anon_cost += cost;
+
+		/*
+		 * Decay previous events
+		 *
+		 * Because workloads change over time (and to avoid
+		 * overflow) we keep these statistics as a floating
+		 * average, which ends up weighing recent refaults
+		 * more than old ones.
+		 */
+		lrusize = lruvec_page_state(lruvec, NR_INACTIVE_ANON) +
+			  lruvec_page_state(lruvec, NR_ACTIVE_ANON) +
+			  lruvec_page_state(lruvec, NR_INACTIVE_FILE) +
+			  lruvec_page_state(lruvec, NR_ACTIVE_FILE);
+
+		if (lruvec->file_cost + lruvec->anon_cost > lrusize / 4) {
+			lruvec->file_cost /= 2;
+			lruvec->anon_cost /= 2;
+		}
+		spin_unlock_irq(&lruvec->lru_lock);
+	} while ((lruvec = parent_lruvec(lruvec)));
+}
+
+void lru_note_cost_refault(struct folio *folio)
+{
+	lru_note_cost(folio_lruvec(folio), folio_is_file_lru(folio),
+		      folio_nr_pages(folio), 0);
+}
+
+static void folio_activate_fn(struct lruvec *lruvec, struct folio *folio)
+{
+	if (!folio_test_active(folio) && !folio_test_unevictable(folio)) {
+		long nr_pages = folio_nr_pages(folio);
+
+		lruvec_del_folio(lruvec, folio);
+		folio_set_active(folio);
+		lruvec_add_folio(lruvec, folio);
+		trace_mm_lru_activate(folio);
+
+		__count_vm_events(PGACTIVATE, nr_pages);
+		__count_memcg_events(lruvec_memcg(lruvec), PGACTIVATE,
+				     nr_pages);
+	}
+}
+
+#ifdef CONFIG_SMP
+static void folio_activate_drain(int cpu)
+{
+	struct folio_batch *fbatch = &per_cpu(cpu_fbatches.activate, cpu);
+
+	if (folio_batch_count(fbatch))
+		folio_batch_move_lru(fbatch, folio_activate_fn);
+}
+
+void folio_activate(struct folio *folio)
+{
+	if (folio_test_lru(folio) && !folio_test_active(folio) &&
+	    !folio_test_unevictable(folio)) {
+		struct folio_batch *fbatch;
+
+		folio_get(folio);
+		local_lock(&cpu_fbatches.lock);
+		fbatch = this_cpu_ptr(&cpu_fbatches.activate);
+		folio_batch_add_and_move(fbatch, folio, folio_activate_fn);
+		local_unlock(&cpu_fbatches.lock);
+	}
+}
+
+#else
+static inline void folio_activate_drain(int cpu)
+{
+}
+
+void folio_activate(struct folio *folio)
+{
+	struct lruvec *lruvec;
+
+	if (folio_test_clear_lru(folio)) {
+		lruvec = folio_lruvec_lock_irq(folio);
+		folio_activate_fn(lruvec, folio);
+		unlock_page_lruvec_irq(lruvec);
+		folio_set_lru(folio);
+	}
+}
+#endif
+
+static void __lru_cache_activate_folio(struct folio *folio)
+{
+	struct folio_batch *fbatch;
+	int i;
+
+	local_lock(&cpu_fbatches.lock);
+	fbatch = this_cpu_ptr(&cpu_fbatches.lru_add);
+
+	/*
+	 * Search backwards on the optimistic assumption that the folio being
+	 * activated has just been added to this batch. Note that only
+	 * the local batch is examined as a !LRU folio could be in the
+	 * process of being released, reclaimed, migrated or on a remote
+	 * batch that is currently being drained. Furthermore, marking
+	 * a remote batch's folio active potentially hits a race where
+	 * a folio is marked active just after it is added to the inactive
+	 * list causing accounting errors and BUG_ON checks to trigger.
+	 */
+	for (i = folio_batch_count(fbatch) - 1; i >= 0; i--) {
+		struct folio *batch_folio = fbatch->folios[i];
+
+		if (batch_folio == folio) {
+			folio_set_active(folio);
+			break;
+		}
+	}
+
+	local_unlock(&cpu_fbatches.lock);
+}
+
+#ifdef CONFIG_LRU_GEN
+static void folio_inc_refs(struct folio *folio)
+{
+	unsigned long new_flags, old_flags = READ_ONCE(folio->flags);
+
+	if (folio_test_unevictable(folio))
+		return;
+
+	if (!folio_test_referenced(folio)) {
+		folio_set_referenced(folio);
+		return;
+	}
+
+	if (!folio_test_workingset(folio)) {
+		folio_set_workingset(folio);
+		return;
+	}
+
+	/* see the comment on MAX_NR_TIERS */
+	do {
+		new_flags = old_flags & LRU_REFS_MASK;
+		if (new_flags == LRU_REFS_MASK)
+			break;
+
+		new_flags += BIT(LRU_REFS_PGOFF);
+		new_flags |= old_flags & ~LRU_REFS_MASK;
+	} while (!try_cmpxchg(&folio->flags, &old_flags, new_flags));
+}
+#else
+static void folio_inc_refs(struct folio *folio)
+{
+}
+#endif /* CONFIG_LRU_GEN */
+
+/*
+ * Mark a page as having seen activity.
+ *
+ * inactive,unreferenced	->	inactive,referenced
+ * inactive,referenced		->	active,unreferenced
+ * active,unreferenced		->	active,referenced
+ *
+ * When a newly allocated page is not yet visible, so safe for non-atomic ops,
+ * __SetPageReferenced(page) may be substituted for mark_page_accessed(page).
+ */
+void folio_mark_accessed(struct folio *folio)
+{
+	if (lru_gen_enabled()) {
+		folio_inc_refs(folio);
+		return;
+	}
+
+	if (!folio_test_referenced(folio)) {
+		folio_set_referenced(folio);
+	} else if (folio_test_unevictable(folio)) {
+		/*
+		 * Unevictable pages are on the "LRU_UNEVICTABLE" list. But,
+		 * this list is never rotated or maintained, so marking an
+		 * unevictable page accessed has no effect.
+		 */
+	} else if (!folio_test_active(folio)) {
+		/*
+		 * If the folio is on the LRU, queue it for activation via
+		 * cpu_fbatches.activate. Otherwise, assume the folio is in a
+		 * folio_batch, mark it active and it'll be moved to the active
+		 * LRU on the next drain.
+		 */
+		if (folio_test_lru(folio))
+			folio_activate(folio);
+		else
+			__lru_cache_activate_folio(folio);
+		folio_clear_referenced(folio);
+		workingset_activation(folio);
+	}
+	if (folio_test_idle(folio))
+		folio_clear_idle(folio);
+}
+EXPORT_SYMBOL(folio_mark_accessed);
+
+/**
+ * folio_add_lru - Add a folio to an LRU list.
+ * @folio: The folio to be added to the LRU.
+ *
+ * Queue the folio for addition to the LRU. The decision on whether
+ * to add the page to the [in]active [file|anon] list is deferred until the
+ * folio_batch is drained. This gives a chance for the caller of folio_add_lru()
+ * have the folio added to the active list using folio_mark_accessed().
+ */
+void folio_add_lru(struct folio *folio)
+{
+	struct folio_batch *fbatch;
+
+	VM_BUG_ON_FOLIO(folio_test_active(folio) &&
+			folio_test_unevictable(folio), folio);
+	VM_BUG_ON_FOLIO(folio_test_lru(folio), folio);
+
+	/* see the comment in lru_gen_add_folio() */
+	if (lru_gen_enabled() && !folio_test_unevictable(folio) &&
+	    lru_gen_in_fault() && !(current->flags & PF_MEMALLOC))
+		folio_set_active(folio);
+
+	folio_get(folio);
+	local_lock(&cpu_fbatches.lock);
+	fbatch = this_cpu_ptr(&cpu_fbatches.lru_add);
+	folio_batch_add_and_move(fbatch, folio, lru_add_fn);
+	local_unlock(&cpu_fbatches.lock);
+}
+EXPORT_SYMBOL(folio_add_lru);
+
+/**
+ * folio_add_lru_vma() - Add a folio to the appropate LRU list for this VMA.
+ * @folio: The folio to be added to the LRU.
+ * @vma: VMA in which the folio is mapped.
+ *
+ * If the VMA is mlocked, @folio is added to the unevictable list.
+ * Otherwise, it is treated the same way as folio_add_lru().
+ */
+void folio_add_lru_vma(struct folio *folio, struct vm_area_struct *vma)
+{
+	VM_BUG_ON_FOLIO(folio_test_lru(folio), folio);
+
+	if (unlikely((vma->vm_flags & (VM_LOCKED | VM_SPECIAL)) == VM_LOCKED))
+		mlock_new_page(&folio->page);
+	else
+		folio_add_lru(folio);
+}
+
+/*
+ * If the folio cannot be invalidated, it is moved to the
+ * inactive list to speed up its reclaim.  It is moved to the
+ * head of the list, rather than the tail, to give the flusher
+ * threads some time to write it out, as this is much more
+ * effective than the single-page writeout from reclaim.
+ *
+ * If the folio isn't mapped and dirty/writeback, the folio
+ * could be reclaimed asap using the reclaim flag.
+ *
+ * 1. active, mapped folio -> none
+ * 2. active, dirty/writeback folio -> inactive, head, reclaim
+ * 3. inactive, mapped folio -> none
+ * 4. inactive, dirty/writeback folio -> inactive, head, reclaim
+ * 5. inactive, clean -> inactive, tail
+ * 6. Others -> none
+ *
+ * In 4, it moves to the head of the inactive list so the folio is
+ * written out by flusher threads as this is much more efficient
+ * than the single-page writeout from reclaim.
+ */
+static void lru_deactivate_file_fn(struct lruvec *lruvec, struct folio *folio)
+{
+	bool active = folio_test_active(folio);
+	long nr_pages = folio_nr_pages(folio);
+
+	if (folio_test_unevictable(folio))
+		return;
+
+	/* Some processes are using the folio */
+	if (folio_mapped(folio))
+		return;
+
+	lruvec_del_folio(lruvec, folio);
+	folio_clear_active(folio);
+	folio_clear_referenced(folio);
+
+	if (folio_test_writeback(folio) || folio_test_dirty(folio)) {
+		/*
+		 * Setting the reclaim flag could race with
+		 * folio_end_writeback() and confuse readahead.  But the
+		 * race window is _really_ small and  it's not a critical
+		 * problem.
+		 */
+		lruvec_add_folio(lruvec, folio);
+		folio_set_reclaim(folio);
+	} else {
+		/*
+		 * The folio's writeback ended while it was in the batch.
+		 * We move that folio to the tail of the inactive list.
+		 */
+		lruvec_add_folio_tail(lruvec, folio);
+		__count_vm_events(PGROTATED, nr_pages);
+	}
+
+	if (active) {
+		__count_vm_events(PGDEACTIVATE, nr_pages);
+		__count_memcg_events(lruvec_memcg(lruvec), PGDEACTIVATE,
+				     nr_pages);
+	}
+}
+
+static void lru_deactivate_fn(struct lruvec *lruvec, struct folio *folio)
+{
+	if (!folio_test_unevictable(folio) && (folio_test_active(folio) || lru_gen_enabled())) {
+		long nr_pages = folio_nr_pages(folio);
+
+		lruvec_del_folio(lruvec, folio);
+		folio_clear_active(folio);
+		folio_clear_referenced(folio);
+		lruvec_add_folio(lruvec, folio);
+
+		__count_vm_events(PGDEACTIVATE, nr_pages);
+		__count_memcg_events(lruvec_memcg(lruvec), PGDEACTIVATE,
+				     nr_pages);
+	}
+}
+
+static void lru_lazyfree_fn(struct lruvec *lruvec, struct folio *folio)
+{
+	if (folio_test_anon(folio) && folio_test_swapbacked(folio) &&
+	    !folio_test_swapcache(folio) && !folio_test_unevictable(folio)) {
+		long nr_pages = folio_nr_pages(folio);
+
+		lruvec_del_folio(lruvec, folio);
+		folio_clear_active(folio);
+		folio_clear_referenced(folio);
+		/*
+		 * Lazyfree folios are clean anonymous folios.  They have
+		 * the swapbacked flag cleared, to distinguish them from normal
+		 * anonymous folios
+		 */
+		folio_clear_swapbacked(folio);
+		lruvec_add_folio(lruvec, folio);
+
+		__count_vm_events(PGLAZYFREE, nr_pages);
+		__count_memcg_events(lruvec_memcg(lruvec), PGLAZYFREE,
+				     nr_pages);
+	}
+}
+
+/*
+ * Drain pages out of the cpu's folio_batch.
+ * Either "cpu" is the current CPU, and preemption has already been
+ * disabled; or "cpu" is being hot-unplugged, and is already dead.
+ */
+void lru_add_drain_cpu(int cpu)
+{
+	struct cpu_fbatches *fbatches = &per_cpu(cpu_fbatches, cpu);
+	struct folio_batch *fbatch = &fbatches->lru_add;
+
+	if (folio_batch_count(fbatch))
+		folio_batch_move_lru(fbatch, lru_add_fn);
+
+	fbatch = &per_cpu(lru_rotate.fbatch, cpu);
+	/* Disabling interrupts below acts as a compiler barrier. */
+	if (data_race(folio_batch_count(fbatch))) {
+		unsigned long flags;
+
+		/* No harm done if a racing interrupt already did this */
+		local_lock_irqsave(&lru_rotate.lock, flags);
+		folio_batch_move_lru(fbatch, lru_move_tail_fn);
+		local_unlock_irqrestore(&lru_rotate.lock, flags);
+	}
+
+	fbatch = &fbatches->lru_deactivate_file;
+	if (folio_batch_count(fbatch))
+		folio_batch_move_lru(fbatch, lru_deactivate_file_fn);
+
+	fbatch = &fbatches->lru_deactivate;
+	if (folio_batch_count(fbatch))
+		folio_batch_move_lru(fbatch, lru_deactivate_fn);
+
+	fbatch = &fbatches->lru_lazyfree;
+	if (folio_batch_count(fbatch))
+		folio_batch_move_lru(fbatch, lru_lazyfree_fn);
+
+	folio_activate_drain(cpu);
+}
+
+/**
+ * deactivate_file_folio() - Deactivate a file folio.
+ * @folio: Folio to deactivate.
+ *
+ * This function hints to the VM that @folio is a good reclaim candidate,
+ * for example if its invalidation fails due to the folio being dirty
+ * or under writeback.
+ *
+ * Context: Caller holds a reference on the folio.
+ */
+void deactivate_file_folio(struct folio *folio)
+{
+	struct folio_batch *fbatch;
+
+	/* Deactivating an unevictable folio will not accelerate reclaim */
+	if (folio_test_unevictable(folio))
+		return;
+
+	folio_get(folio);
+	local_lock(&cpu_fbatches.lock);
+	fbatch = this_cpu_ptr(&cpu_fbatches.lru_deactivate_file);
+	folio_batch_add_and_move(fbatch, folio, lru_deactivate_file_fn);
+	local_unlock(&cpu_fbatches.lock);
+}
+
+/*
+ * deactivate_page - deactivate a page
+ * @page: page to deactivate
+ *
+ * deactivate_page() moves @page to the inactive list if @page was on the active
+ * list and was not an unevictable page.  This is done to accelerate the reclaim
+ * of @page.
+ */
+void deactivate_page(struct page *page)
+{
+	struct folio *folio = page_folio(page);
+
+	if (folio_test_lru(folio) && !folio_test_unevictable(folio) &&
+	    (folio_test_active(folio) || lru_gen_enabled())) {
+		struct folio_batch *fbatch;
+
+		folio_get(folio);
+		local_lock(&cpu_fbatches.lock);
+		fbatch = this_cpu_ptr(&cpu_fbatches.lru_deactivate);
+		folio_batch_add_and_move(fbatch, folio, lru_deactivate_fn);
+		local_unlock(&cpu_fbatches.lock);
+	}
+}
+
+/**
+ * mark_page_lazyfree - make an anon page lazyfree
+ * @page: page to deactivate
+ *
+ * mark_page_lazyfree() moves @page to the inactive file list.
+ * This is done to accelerate the reclaim of @page.
+ */
+void mark_page_lazyfree(struct page *page)
+{
+	struct folio *folio = page_folio(page);
+
+	if (folio_test_lru(folio) && folio_test_anon(folio) &&
+	    folio_test_swapbacked(folio) && !folio_test_swapcache(folio) &&
+	    !folio_test_unevictable(folio)) {
+		struct folio_batch *fbatch;
+
+		folio_get(folio);
+		local_lock(&cpu_fbatches.lock);
+		fbatch = this_cpu_ptr(&cpu_fbatches.lru_lazyfree);
+		folio_batch_add_and_move(fbatch, folio, lru_lazyfree_fn);
+		local_unlock(&cpu_fbatches.lock);
+	}
+}
+
+void lru_add_drain(void)
+{
+	local_lock(&cpu_fbatches.lock);
+	lru_add_drain_cpu(smp_processor_id());
+	local_unlock(&cpu_fbatches.lock);
+	mlock_page_drain_local();
+}
+
+/*
+ * It's called from per-cpu workqueue context in SMP case so
+ * lru_add_drain_cpu and invalidate_bh_lrus_cpu should run on
+ * the same cpu. It shouldn't be a problem in !SMP case since
+ * the core is only one and the locks will disable preemption.
+ */
+static void lru_add_and_bh_lrus_drain(void)
+{
+	local_lock(&cpu_fbatches.lock);
+	lru_add_drain_cpu(smp_processor_id());
+	local_unlock(&cpu_fbatches.lock);
+	invalidate_bh_lrus_cpu();
+	mlock_page_drain_local();
+}
+
+void lru_add_drain_cpu_zone(struct zone *zone)
+{
+	local_lock(&cpu_fbatches.lock);
+	lru_add_drain_cpu(smp_processor_id());
+	drain_local_pages(zone);
+	local_unlock(&cpu_fbatches.lock);
+	mlock_page_drain_local();
+}
+
+#ifdef CONFIG_SMP
+
+static DEFINE_PER_CPU(struct work_struct, lru_add_drain_work);
+
+static void lru_add_drain_per_cpu(struct work_struct *dummy)
+{
+	lru_add_and_bh_lrus_drain();
+}
+
+static bool cpu_needs_drain(unsigned int cpu)
+{
+	struct cpu_fbatches *fbatches = &per_cpu(cpu_fbatches, cpu);
+
+	/* Check these in order of likelihood that they're not zero */
+	return folio_batch_count(&fbatches->lru_add) ||
+		data_race(folio_batch_count(&per_cpu(lru_rotate.fbatch, cpu))) ||
+		folio_batch_count(&fbatches->lru_deactivate_file) ||
+		folio_batch_count(&fbatches->lru_deactivate) ||
+		folio_batch_count(&fbatches->lru_lazyfree) ||
+		folio_batch_count(&fbatches->activate) ||
+		need_mlock_page_drain(cpu) ||
+		has_bh_in_lru(cpu, NULL);
+}
+
+/*
+ * Doesn't need any cpu hotplug locking because we do rely on per-cpu
+ * kworkers being shut down before our page_alloc_cpu_dead callback is
+ * executed on the offlined cpu.
+ * Calling this function with cpu hotplug locks held can actually lead
+ * to obscure indirect dependencies via WQ context.
+ */
+static inline void __lru_add_drain_all(bool force_all_cpus)
+{
+	/*
+	 * lru_drain_gen - Global pages generation number
+	 *
+	 * (A) Definition: global lru_drain_gen = x implies that all generations
+	 *     0 < n <= x are already *scheduled* for draining.
+	 *
+	 * This is an optimization for the highly-contended use case where a
+	 * user space workload keeps constantly generating a flow of pages for
+	 * each CPU.
+	 */
+	static unsigned int lru_drain_gen;
+	static struct cpumask has_work;
+	static DEFINE_MUTEX(lock);
+	unsigned cpu, this_gen;
+
+	/*
+	 * Make sure nobody triggers this path before mm_percpu_wq is fully
+	 * initialized.
+	 */
+	if (WARN_ON(!mm_percpu_wq))
+		return;
+
+	/*
+	 * Guarantee folio_batch counter stores visible by this CPU
+	 * are visible to other CPUs before loading the current drain
+	 * generation.
+	 */
+	smp_mb();
+
+	/*
+	 * (B) Locally cache global LRU draining generation number
+	 *
+	 * The read barrier ensures that the counter is loaded before the mutex
+	 * is taken. It pairs with smp_mb() inside the mutex critical section
+	 * at (D).
+	 */
+	this_gen = smp_load_acquire(&lru_drain_gen);
+
+	mutex_lock(&lock);
+
+	/*
+	 * (C) Exit the draining operation if a newer generation, from another
+	 * lru_add_drain_all(), was already scheduled for draining. Check (A).
+	 */
+	if (unlikely(this_gen != lru_drain_gen && !force_all_cpus))
+		goto done;
+
+	/*
+	 * (D) Increment global generation number
+	 *
+	 * Pairs with smp_load_acquire() at (B), outside of the critical
+	 * section. Use a full memory barrier to guarantee that the
+	 * new global drain generation number is stored before loading
+	 * folio_batch counters.
+	 *
+	 * This pairing must be done here, before the for_each_online_cpu loop
+	 * below which drains the page vectors.
+	 *
+	 * Let x, y, and z represent some system CPU numbers, where x < y < z.
+	 * Assume CPU #z is in the middle of the for_each_online_cpu loop
+	 * below and has already reached CPU #y's per-cpu data. CPU #x comes
+	 * along, adds some pages to its per-cpu vectors, then calls
+	 * lru_add_drain_all().
+	 *
+	 * If the paired barrier is done at any later step, e.g. after the
+	 * loop, CPU #x will just exit at (C) and miss flushing out all of its
+	 * added pages.
+	 */
+	WRITE_ONCE(lru_drain_gen, lru_drain_gen + 1);
+	smp_mb();
+
+	cpumask_clear(&has_work);
+	for_each_online_cpu(cpu) {
+		struct work_struct *work = &per_cpu(lru_add_drain_work, cpu);
+
+		if (cpu_needs_drain(cpu)) {
+			INIT_WORK(work, lru_add_drain_per_cpu);
+			queue_work_on(cpu, mm_percpu_wq, work);
+			__cpumask_set_cpu(cpu, &has_work);
+		}
+	}
+
+	for_each_cpu(cpu, &has_work)
+		flush_work(&per_cpu(lru_add_drain_work, cpu));
+
+done:
+	mutex_unlock(&lock);
+}
+
+void lru_add_drain_all(void)
+{
+	__lru_add_drain_all(false);
+}
+#else
+void lru_add_drain_all(void)
+{
+	lru_add_drain();
+}
+#endif /* CONFIG_SMP */
+
+atomic_t lru_disable_count = ATOMIC_INIT(0);
+
+/*
+ * lru_cache_disable() needs to be called before we start compiling
+ * a list of pages to be migrated using isolate_lru_page().
+ * It drains pages on LRU cache and then disable on all cpus until
+ * lru_cache_enable is called.
+ *
+ * Must be paired with a call to lru_cache_enable().
+ */
+void lru_cache_disable(void)
+{
+	atomic_inc(&lru_disable_count);
+	/*
+	 * Readers of lru_disable_count are protected by either disabling
+	 * preemption or rcu_read_lock:
+	 *
+	 * preempt_disable, local_irq_disable  [bh_lru_lock()]
+	 * rcu_read_lock		       [rt_spin_lock CONFIG_PREEMPT_RT]
+	 * preempt_disable		       [local_lock !CONFIG_PREEMPT_RT]
+	 *
+	 * Since v5.1 kernel, synchronize_rcu() is guaranteed to wait on
+	 * preempt_disable() regions of code. So any CPU which sees
+	 * lru_disable_count = 0 will have exited the critical
+	 * section when synchronize_rcu() returns.
+	 */
+	synchronize_rcu_expedited();
+#ifdef CONFIG_SMP
+	__lru_add_drain_all(true);
+#else
+	lru_add_and_bh_lrus_drain();
+#endif
+}
+
+/**
+ * release_pages - batched put_page()
+ * @arg: array of pages to release
+ * @nr: number of pages
+ *
+ * Decrement the reference count on all the pages in @arg.  If it
+ * fell to zero, remove the page from the LRU and free it.
+ *
+ * Note that the argument can be an array of pages, encoded pages,
+ * or folio pointers. We ignore any encoded bits, and turn any of
+ * them into just a folio that gets free'd.
+ */
+void release_pages(release_pages_arg arg, int nr)
+{
+	int i;
+	struct encoded_page **encoded = arg.encoded_pages;
+	LIST_HEAD(pages_to_free);
+	struct lruvec *lruvec = NULL;
+	unsigned long flags = 0;
+	unsigned int lock_batch;
+
+	for (i = 0; i < nr; i++) {
+		struct folio *folio;
+
+		/* Turn any of the argument types into a folio */
+		folio = page_folio(encoded_page_ptr(encoded[i]));
+
+		/*
+		 * Make sure the IRQ-safe lock-holding time does not get
+		 * excessive with a continuous string of pages from the
+		 * same lruvec. The lock is held only if lruvec != NULL.
+		 */
+		if (lruvec && ++lock_batch == SWAP_CLUSTER_MAX) {
+			unlock_page_lruvec_irqrestore(lruvec, flags);
+			lruvec = NULL;
+		}
+
+		if (is_huge_zero_page(&folio->page))
+			continue;
+
+		if (folio_is_zone_device(folio)) {
+			if (lruvec) {
+				unlock_page_lruvec_irqrestore(lruvec, flags);
+				lruvec = NULL;
+			}
+			if (put_devmap_managed_page(&folio->page))
+				continue;
+			if (folio_put_testzero(folio))
+				free_zone_device_page(&folio->page);
+			continue;
+		}
+
+		if (!folio_put_testzero(folio))
+			continue;
+
+		if (folio_test_large(folio)) {
+			if (lruvec) {
+				unlock_page_lruvec_irqrestore(lruvec, flags);
+				lruvec = NULL;
+			}
+			__folio_put_large(folio);
+			continue;
+		}
+
+		if (folio_test_lru(folio)) {
+			struct lruvec *prev_lruvec = lruvec;
+
+			lruvec = folio_lruvec_relock_irqsave(folio, lruvec,
+									&flags);
+			if (prev_lruvec != lruvec)
+				lock_batch = 0;
+
+			lruvec_del_folio(lruvec, folio);
+			__folio_clear_lru_flags(folio);
+		}
+
+		/*
+		 * In rare cases, when truncation or holepunching raced with
+		 * munlock after VM_LOCKED was cleared, Mlocked may still be
+		 * found set here.  This does not indicate a problem, unless
+		 * "unevictable_pgs_cleared" appears worryingly large.
+		 */
+		if (unlikely(folio_test_mlocked(folio))) {
+			__folio_clear_mlocked(folio);
+			zone_stat_sub_folio(folio, NR_MLOCK);
+			count_vm_event(UNEVICTABLE_PGCLEARED);
+		}
+
+		list_add(&folio->lru, &pages_to_free);
+	}
+	if (lruvec)
+		unlock_page_lruvec_irqrestore(lruvec, flags);
+
+	mem_cgroup_uncharge_list(&pages_to_free);
+	free_unref_page_list(&pages_to_free);
+}
+EXPORT_SYMBOL(release_pages);
+
+/*
+ * The pages which we're about to release may be in the deferred lru-addition
+ * queues.  That would prevent them from really being freed right now.  That's
+ * OK from a correctness point of view but is inefficient - those pages may be
+ * cache-warm and we want to give them back to the page allocator ASAP.
+ *
+ * So __pagevec_release() will drain those queues here.
+ * folio_batch_move_lru() calls folios_put() directly to avoid
+ * mutual recursion.
+ */
+void __pagevec_release(struct pagevec *pvec)
+{
+	if (!pvec->percpu_pvec_drained) {
+		lru_add_drain();
+		pvec->percpu_pvec_drained = true;
+	}
+	release_pages(pvec->pages, pagevec_count(pvec));
+	pagevec_reinit(pvec);
+}
+EXPORT_SYMBOL(__pagevec_release);
+
+/**
+ * folio_batch_remove_exceptionals() - Prune non-folios from a batch.
+ * @fbatch: The batch to prune
+ *
+ * find_get_entries() fills a batch with both folios and shadow/swap/DAX
+ * entries.  This function prunes all the non-folio entries from @fbatch
+ * without leaving holes, so that it can be passed on to folio-only batch
+ * operations.
+ */
+void folio_batch_remove_exceptionals(struct folio_batch *fbatch)
+{
+	unsigned int i, j;
+
+	for (i = 0, j = 0; i < folio_batch_count(fbatch); i++) {
+		struct folio *folio = fbatch->folios[i];
+		if (!xa_is_value(folio))
+			fbatch->folios[j++] = folio;
+	}
+	fbatch->nr = j;
+}
+
+unsigned pagevec_lookup_range_tag(struct pagevec *pvec,
+		struct address_space *mapping, pgoff_t *index, pgoff_t end,
+		xa_mark_t tag)
+{
+	pvec->nr = find_get_pages_range_tag(mapping, index, end, tag,
+					PAGEVEC_SIZE, pvec->pages);
+	return pagevec_count(pvec);
+}
+EXPORT_SYMBOL(pagevec_lookup_range_tag);
+
+/*
+ * Perform any setup for the swap system
+ */
+void __init swap_setup(void)
+{
+	unsigned long megs = totalram_pages() >> (20 - PAGE_SHIFT);
+
+	/* Use a smaller cluster for small-memory machines */
+	if (megs < 16)
+		page_cluster = 2;
+	else
+		page_cluster = 3;
+	/*
+	 * Right now other parts of the system means that we
+	 * _really_ don't want to cluster much more
+	 */
+}