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authorLinus Torvalds <torvalds@linux-foundation.org>2022-01-22 11:28:23 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2022-01-22 11:28:23 +0200
commit1c52283265a462a100ae63ddf58b4e5884acde86 (patch)
treec0d3fa7a02fc0111bc7e56aa1be88e9b92795704 /mm
parent8205ae327e396820fb7a176a94768146ac0b87ea (diff)
parent6e61dde82e8bfe65e8ebbe43da45e615bc529236 (diff)
downloadlinux-1c52283265a462a100ae63ddf58b4e5884acde86.tar.bz2
Merge branch 'akpm' (patches from Andrew)
Merge yet more updates from Andrew Morton: "This is the post-linux-next queue. Material which was based on or dependent upon material which was in -next. 69 patches. Subsystems affected by this patch series: mm (migration and zsmalloc), sysctl, proc, and lib" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (69 commits) mm: hide the FRONTSWAP Kconfig symbol frontswap: remove support for multiple ops mm: mark swap_lock and swap_active_head static frontswap: simplify frontswap_register_ops frontswap: remove frontswap_test mm: simplify try_to_unuse frontswap: remove the frontswap exports frontswap: simplify frontswap_init frontswap: remove frontswap_curr_pages frontswap: remove frontswap_shrink frontswap: remove frontswap_tmem_exclusive_gets frontswap: remove frontswap_writethrough mm: remove cleancache lib/stackdepot: always do filter_irq_stacks() in stack_depot_save() lib/stackdepot: allow optional init and stack_table allocation by kvmalloc() proc: remove PDE_DATA() completely fs: proc: store PDE()->data into inode->i_private zsmalloc: replace get_cpu_var with local_lock zsmalloc: replace per zpage lock with pool->migrate_lock locking/rwlocks: introduce write_lock_nested ...
Diffstat (limited to 'mm')
-rw-r--r--mm/Kconfig40
-rw-r--r--mm/Makefile1
-rw-r--r--mm/cleancache.c315
-rw-r--r--mm/filemap.c102
-rw-r--r--mm/frontswap.c259
-rw-r--r--mm/kasan/common.c1
-rw-r--r--mm/migrate.c38
-rw-r--r--mm/page_owner.c2
-rw-r--r--mm/shmem.c33
-rw-r--r--mm/swapfile.c90
-rw-r--r--mm/truncate.c15
-rw-r--r--mm/zsmalloc.c529
-rw-r--r--mm/zswap.c8
13 files changed, 345 insertions, 1088 deletions
diff --git a/mm/Kconfig b/mm/Kconfig
index a99bd499ef51..3326ee3903f3 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -444,43 +444,8 @@ config USE_PERCPU_NUMA_NODE_ID
config HAVE_SETUP_PER_CPU_AREA
bool
-config CLEANCACHE
- bool "Enable cleancache driver to cache clean pages if tmem is present"
- help
- Cleancache can be thought of as a page-granularity victim cache
- for clean pages that the kernel's pageframe replacement algorithm
- (PFRA) would like to keep around, but can't since there isn't enough
- memory. So when the PFRA "evicts" a page, it first attempts to use
- cleancache code to put the data contained in that page into
- "transcendent memory", memory that is not directly accessible or
- addressable by the kernel and is of unknown and possibly
- time-varying size. And when a cleancache-enabled
- filesystem wishes to access a page in a file on disk, it first
- checks cleancache to see if it already contains it; if it does,
- the page is copied into the kernel and a disk access is avoided.
- When a transcendent memory driver is available (such as zcache or
- Xen transcendent memory), a significant I/O reduction
- may be achieved. When none is available, all cleancache calls
- are reduced to a single pointer-compare-against-NULL resulting
- in a negligible performance hit.
-
- If unsure, say Y to enable cleancache
-
config FRONTSWAP
- bool "Enable frontswap to cache swap pages if tmem is present"
- depends on SWAP
- help
- Frontswap is so named because it can be thought of as the opposite
- of a "backing" store for a swap device. The data is stored into
- "transcendent memory", memory that is not directly accessible or
- addressable by the kernel and is of unknown and possibly
- time-varying size. When space in transcendent memory is available,
- a significant swap I/O reduction may be achieved. When none is
- available, all frontswap calls are reduced to a single pointer-
- compare-against-NULL resulting in a negligible performance hit
- and swap data is stored as normal on the matching swap device.
-
- If unsure, say Y to enable frontswap.
+ bool
config CMA
bool "Contiguous Memory Allocator"
@@ -545,7 +510,8 @@ config MEM_SOFT_DIRTY
config ZSWAP
bool "Compressed cache for swap pages (EXPERIMENTAL)"
- depends on FRONTSWAP && CRYPTO=y
+ depends on SWAP && CRYPTO=y
+ select FRONTSWAP
select ZPOOL
help
A lightweight compressed cache for swap pages. It takes
diff --git a/mm/Makefile b/mm/Makefile
index 588d3113f3b0..70d4309c9ce3 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -104,7 +104,6 @@ obj-$(CONFIG_DEBUG_KMEMLEAK) += kmemleak.o
obj-$(CONFIG_DEBUG_RODATA_TEST) += rodata_test.o
obj-$(CONFIG_DEBUG_VM_PGTABLE) += debug_vm_pgtable.o
obj-$(CONFIG_PAGE_OWNER) += page_owner.o
-obj-$(CONFIG_CLEANCACHE) += cleancache.o
obj-$(CONFIG_MEMORY_ISOLATION) += page_isolation.o
obj-$(CONFIG_ZPOOL) += zpool.o
obj-$(CONFIG_ZBUD) += zbud.o
diff --git a/mm/cleancache.c b/mm/cleancache.c
deleted file mode 100644
index db7eee9c0886..000000000000
--- a/mm/cleancache.c
+++ /dev/null
@@ -1,315 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * Cleancache frontend
- *
- * This code provides the generic "frontend" layer to call a matching
- * "backend" driver implementation of cleancache. See
- * Documentation/vm/cleancache.rst for more information.
- *
- * Copyright (C) 2009-2010 Oracle Corp. All rights reserved.
- * Author: Dan Magenheimer
- */
-
-#include <linux/module.h>
-#include <linux/fs.h>
-#include <linux/exportfs.h>
-#include <linux/mm.h>
-#include <linux/debugfs.h>
-#include <linux/cleancache.h>
-
-/*
- * cleancache_ops is set by cleancache_register_ops to contain the pointers
- * to the cleancache "backend" implementation functions.
- */
-static const struct cleancache_ops *cleancache_ops __read_mostly;
-
-/*
- * Counters available via /sys/kernel/debug/cleancache (if debugfs is
- * properly configured. These are for information only so are not protected
- * against increment races.
- */
-static u64 cleancache_succ_gets;
-static u64 cleancache_failed_gets;
-static u64 cleancache_puts;
-static u64 cleancache_invalidates;
-
-static void cleancache_register_ops_sb(struct super_block *sb, void *unused)
-{
- switch (sb->cleancache_poolid) {
- case CLEANCACHE_NO_BACKEND:
- __cleancache_init_fs(sb);
- break;
- case CLEANCACHE_NO_BACKEND_SHARED:
- __cleancache_init_shared_fs(sb);
- break;
- }
-}
-
-/*
- * Register operations for cleancache. Returns 0 on success.
- */
-int cleancache_register_ops(const struct cleancache_ops *ops)
-{
- if (cmpxchg(&cleancache_ops, NULL, ops))
- return -EBUSY;
-
- /*
- * A cleancache backend can be built as a module and hence loaded after
- * a cleancache enabled filesystem has called cleancache_init_fs. To
- * handle such a scenario, here we call ->init_fs or ->init_shared_fs
- * for each active super block. To differentiate between local and
- * shared filesystems, we temporarily initialize sb->cleancache_poolid
- * to CLEANCACHE_NO_BACKEND or CLEANCACHE_NO_BACKEND_SHARED
- * respectively in case there is no backend registered at the time
- * cleancache_init_fs or cleancache_init_shared_fs is called.
- *
- * Since filesystems can be mounted concurrently with cleancache
- * backend registration, we have to be careful to guarantee that all
- * cleancache enabled filesystems that has been mounted by the time
- * cleancache_register_ops is called has got and all mounted later will
- * get cleancache_poolid. This is assured by the following statements
- * tied together:
- *
- * a) iterate_supers skips only those super blocks that has started
- * ->kill_sb
- *
- * b) if iterate_supers encounters a super block that has not finished
- * ->mount yet, it waits until it is finished
- *
- * c) cleancache_init_fs is called from ->mount and
- * cleancache_invalidate_fs is called from ->kill_sb
- *
- * d) we call iterate_supers after cleancache_ops has been set
- *
- * From a) it follows that if iterate_supers skips a super block, then
- * either the super block is already dead, in which case we do not need
- * to bother initializing cleancache for it, or it was mounted after we
- * initiated iterate_supers. In the latter case, it must have seen
- * cleancache_ops set according to d) and initialized cleancache from
- * ->mount by itself according to c). This proves that we call
- * ->init_fs at least once for each active super block.
- *
- * From b) and c) it follows that if iterate_supers encounters a super
- * block that has already started ->init_fs, it will wait until ->mount
- * and hence ->init_fs has finished, then check cleancache_poolid, see
- * that it has already been set and therefore do nothing. This proves
- * that we call ->init_fs no more than once for each super block.
- *
- * Combined together, the last two paragraphs prove the function
- * correctness.
- *
- * Note that various cleancache callbacks may proceed before this
- * function is called or even concurrently with it, but since
- * CLEANCACHE_NO_BACKEND is negative, they will all result in a noop
- * until the corresponding ->init_fs has been actually called and
- * cleancache_ops has been set.
- */
- iterate_supers(cleancache_register_ops_sb, NULL);
- return 0;
-}
-EXPORT_SYMBOL(cleancache_register_ops);
-
-/* Called by a cleancache-enabled filesystem at time of mount */
-void __cleancache_init_fs(struct super_block *sb)
-{
- int pool_id = CLEANCACHE_NO_BACKEND;
-
- if (cleancache_ops) {
- pool_id = cleancache_ops->init_fs(PAGE_SIZE);
- if (pool_id < 0)
- pool_id = CLEANCACHE_NO_POOL;
- }
- sb->cleancache_poolid = pool_id;
-}
-EXPORT_SYMBOL(__cleancache_init_fs);
-
-/* Called by a cleancache-enabled clustered filesystem at time of mount */
-void __cleancache_init_shared_fs(struct super_block *sb)
-{
- int pool_id = CLEANCACHE_NO_BACKEND_SHARED;
-
- if (cleancache_ops) {
- pool_id = cleancache_ops->init_shared_fs(&sb->s_uuid, PAGE_SIZE);
- if (pool_id < 0)
- pool_id = CLEANCACHE_NO_POOL;
- }
- sb->cleancache_poolid = pool_id;
-}
-EXPORT_SYMBOL(__cleancache_init_shared_fs);
-
-/*
- * If the filesystem uses exportable filehandles, use the filehandle as
- * the key, else use the inode number.
- */
-static int cleancache_get_key(struct inode *inode,
- struct cleancache_filekey *key)
-{
- int (*fhfn)(struct inode *, __u32 *fh, int *, struct inode *);
- int len = 0, maxlen = CLEANCACHE_KEY_MAX;
- struct super_block *sb = inode->i_sb;
-
- key->u.ino = inode->i_ino;
- if (sb->s_export_op != NULL) {
- fhfn = sb->s_export_op->encode_fh;
- if (fhfn) {
- len = (*fhfn)(inode, &key->u.fh[0], &maxlen, NULL);
- if (len <= FILEID_ROOT || len == FILEID_INVALID)
- return -1;
- if (maxlen > CLEANCACHE_KEY_MAX)
- return -1;
- }
- }
- return 0;
-}
-
-/*
- * "Get" data from cleancache associated with the poolid/inode/index
- * that were specified when the data was put to cleanache and, if
- * successful, use it to fill the specified page with data and return 0.
- * The pageframe is unchanged and returns -1 if the get fails.
- * Page must be locked by caller.
- *
- * The function has two checks before any action is taken - whether
- * a backend is registered and whether the sb->cleancache_poolid
- * is correct.
- */
-int __cleancache_get_page(struct page *page)
-{
- int ret = -1;
- int pool_id;
- struct cleancache_filekey key = { .u.key = { 0 } };
-
- if (!cleancache_ops) {
- cleancache_failed_gets++;
- goto out;
- }
-
- VM_BUG_ON_PAGE(!PageLocked(page), page);
- pool_id = page->mapping->host->i_sb->cleancache_poolid;
- if (pool_id < 0)
- goto out;
-
- if (cleancache_get_key(page->mapping->host, &key) < 0)
- goto out;
-
- ret = cleancache_ops->get_page(pool_id, key, page->index, page);
- if (ret == 0)
- cleancache_succ_gets++;
- else
- cleancache_failed_gets++;
-out:
- return ret;
-}
-EXPORT_SYMBOL(__cleancache_get_page);
-
-/*
- * "Put" data from a page to cleancache and associate it with the
- * (previously-obtained per-filesystem) poolid and the page's,
- * inode and page index. Page must be locked. Note that a put_page
- * always "succeeds", though a subsequent get_page may succeed or fail.
- *
- * The function has two checks before any action is taken - whether
- * a backend is registered and whether the sb->cleancache_poolid
- * is correct.
- */
-void __cleancache_put_page(struct page *page)
-{
- int pool_id;
- struct cleancache_filekey key = { .u.key = { 0 } };
-
- if (!cleancache_ops) {
- cleancache_puts++;
- return;
- }
-
- VM_BUG_ON_PAGE(!PageLocked(page), page);
- pool_id = page->mapping->host->i_sb->cleancache_poolid;
- if (pool_id >= 0 &&
- cleancache_get_key(page->mapping->host, &key) >= 0) {
- cleancache_ops->put_page(pool_id, key, page->index, page);
- cleancache_puts++;
- }
-}
-EXPORT_SYMBOL(__cleancache_put_page);
-
-/*
- * Invalidate any data from cleancache associated with the poolid and the
- * page's inode and page index so that a subsequent "get" will fail.
- *
- * The function has two checks before any action is taken - whether
- * a backend is registered and whether the sb->cleancache_poolid
- * is correct.
- */
-void __cleancache_invalidate_page(struct address_space *mapping,
- struct page *page)
-{
- /* careful... page->mapping is NULL sometimes when this is called */
- int pool_id = mapping->host->i_sb->cleancache_poolid;
- struct cleancache_filekey key = { .u.key = { 0 } };
-
- if (!cleancache_ops)
- return;
-
- if (pool_id >= 0) {
- VM_BUG_ON_PAGE(!PageLocked(page), page);
- if (cleancache_get_key(mapping->host, &key) >= 0) {
- cleancache_ops->invalidate_page(pool_id,
- key, page->index);
- cleancache_invalidates++;
- }
- }
-}
-EXPORT_SYMBOL(__cleancache_invalidate_page);
-
-/*
- * Invalidate all data from cleancache associated with the poolid and the
- * mappings's inode so that all subsequent gets to this poolid/inode
- * will fail.
- *
- * The function has two checks before any action is taken - whether
- * a backend is registered and whether the sb->cleancache_poolid
- * is correct.
- */
-void __cleancache_invalidate_inode(struct address_space *mapping)
-{
- int pool_id = mapping->host->i_sb->cleancache_poolid;
- struct cleancache_filekey key = { .u.key = { 0 } };
-
- if (!cleancache_ops)
- return;
-
- if (pool_id >= 0 && cleancache_get_key(mapping->host, &key) >= 0)
- cleancache_ops->invalidate_inode(pool_id, key);
-}
-EXPORT_SYMBOL(__cleancache_invalidate_inode);
-
-/*
- * Called by any cleancache-enabled filesystem at time of unmount;
- * note that pool_id is surrendered and may be returned by a subsequent
- * cleancache_init_fs or cleancache_init_shared_fs.
- */
-void __cleancache_invalidate_fs(struct super_block *sb)
-{
- int pool_id;
-
- pool_id = sb->cleancache_poolid;
- sb->cleancache_poolid = CLEANCACHE_NO_POOL;
-
- if (cleancache_ops && pool_id >= 0)
- cleancache_ops->invalidate_fs(pool_id);
-}
-EXPORT_SYMBOL(__cleancache_invalidate_fs);
-
-static int __init init_cleancache(void)
-{
-#ifdef CONFIG_DEBUG_FS
- struct dentry *root = debugfs_create_dir("cleancache", NULL);
-
- debugfs_create_u64("succ_gets", 0444, root, &cleancache_succ_gets);
- debugfs_create_u64("failed_gets", 0444, root, &cleancache_failed_gets);
- debugfs_create_u64("puts", 0444, root, &cleancache_puts);
- debugfs_create_u64("invalidates", 0444, root, &cleancache_invalidates);
-#endif
- return 0;
-}
-module_init(init_cleancache)
diff --git a/mm/filemap.c b/mm/filemap.c
index afc8f5ca85ac..ad8c39d90bf9 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -21,6 +21,7 @@
#include <linux/gfp.h>
#include <linux/mm.h>
#include <linux/swap.h>
+#include <linux/swapops.h>
#include <linux/mman.h>
#include <linux/pagemap.h>
#include <linux/file.h>
@@ -34,13 +35,13 @@
#include <linux/cpuset.h>
#include <linux/hugetlb.h>
#include <linux/memcontrol.h>
-#include <linux/cleancache.h>
#include <linux/shmem_fs.h>
#include <linux/rmap.h>
#include <linux/delayacct.h>
#include <linux/psi.h>
#include <linux/ramfs.h>
#include <linux/page_idle.h>
+#include <linux/migrate.h>
#include <asm/pgalloc.h>
#include <asm/tlbflush.h>
#include "internal.h"
@@ -149,16 +150,6 @@ static void filemap_unaccount_folio(struct address_space *mapping,
{
long nr;
- /*
- * if we're uptodate, flush out into the cleancache, otherwise
- * invalidate any existing cleancache entries. We can't leave
- * stale data around in the cleancache once our page is gone
- */
- if (folio_test_uptodate(folio) && folio_test_mappedtodisk(folio))
- cleancache_put_page(&folio->page);
- else
- cleancache_invalidate_page(mapping, &folio->page);
-
VM_BUG_ON_FOLIO(folio_mapped(folio), folio);
if (!IS_ENABLED(CONFIG_DEBUG_VM) && unlikely(folio_mapped(folio))) {
int mapcount;
@@ -1386,6 +1377,95 @@ repeat:
return wait->flags & WQ_FLAG_WOKEN ? 0 : -EINTR;
}
+#ifdef CONFIG_MIGRATION
+/**
+ * migration_entry_wait_on_locked - Wait for a migration entry to be removed
+ * @entry: migration swap entry.
+ * @ptep: mapped pte pointer. Will return with the ptep unmapped. Only required
+ * for pte entries, pass NULL for pmd entries.
+ * @ptl: already locked ptl. This function will drop the lock.
+ *
+ * Wait for a migration entry referencing the given page to be removed. This is
+ * equivalent to put_and_wait_on_page_locked(page, TASK_UNINTERRUPTIBLE) except
+ * this can be called without taking a reference on the page. Instead this
+ * should be called while holding the ptl for the migration entry referencing
+ * the page.
+ *
+ * Returns after unmapping and unlocking the pte/ptl with pte_unmap_unlock().
+ *
+ * This follows the same logic as folio_wait_bit_common() so see the comments
+ * there.
+ */
+void migration_entry_wait_on_locked(swp_entry_t entry, pte_t *ptep,
+ spinlock_t *ptl)
+{
+ struct wait_page_queue wait_page;
+ wait_queue_entry_t *wait = &wait_page.wait;
+ bool thrashing = false;
+ bool delayacct = false;
+ unsigned long pflags;
+ wait_queue_head_t *q;
+ struct folio *folio = page_folio(pfn_swap_entry_to_page(entry));
+
+ q = folio_waitqueue(folio);
+ if (!folio_test_uptodate(folio) && folio_test_workingset(folio)) {
+ if (!folio_test_swapbacked(folio)) {
+ delayacct_thrashing_start();
+ delayacct = true;
+ }
+ psi_memstall_enter(&pflags);
+ thrashing = true;
+ }
+
+ init_wait(wait);
+ wait->func = wake_page_function;
+ wait_page.folio = folio;
+ wait_page.bit_nr = PG_locked;
+ wait->flags = 0;
+
+ spin_lock_irq(&q->lock);
+ folio_set_waiters(folio);
+ if (!folio_trylock_flag(folio, PG_locked, wait))
+ __add_wait_queue_entry_tail(q, wait);
+ spin_unlock_irq(&q->lock);
+
+ /*
+ * If a migration entry exists for the page the migration path must hold
+ * a valid reference to the page, and it must take the ptl to remove the
+ * migration entry. So the page is valid until the ptl is dropped.
+ */
+ if (ptep)
+ pte_unmap_unlock(ptep, ptl);
+ else
+ spin_unlock(ptl);
+
+ for (;;) {
+ unsigned int flags;
+
+ set_current_state(TASK_UNINTERRUPTIBLE);
+
+ /* Loop until we've been woken or interrupted */
+ flags = smp_load_acquire(&wait->flags);
+ if (!(flags & WQ_FLAG_WOKEN)) {
+ if (signal_pending_state(TASK_UNINTERRUPTIBLE, current))
+ break;
+
+ io_schedule();
+ continue;
+ }
+ break;
+ }
+
+ finish_wait(q, wait);
+
+ if (thrashing) {
+ if (delayacct)
+ delayacct_thrashing_end();
+ psi_memstall_leave(&pflags);
+ }
+}
+#endif
+
void folio_wait_bit(struct folio *folio, int bit_nr)
{
folio_wait_bit_common(folio, bit_nr, TASK_UNINTERRUPTIBLE, SHARED);
diff --git a/mm/frontswap.c b/mm/frontswap.c
index 6bed12260dea..6f69b044a8cc 100644
--- a/mm/frontswap.c
+++ b/mm/frontswap.c
@@ -27,27 +27,7 @@ DEFINE_STATIC_KEY_FALSE(frontswap_enabled_key);
* may be registered, but implementations can never deregister. This
* is a simple singly-linked list of all registered implementations.
*/
-static struct frontswap_ops *frontswap_ops __read_mostly;
-
-#define for_each_frontswap_ops(ops) \
- for ((ops) = frontswap_ops; (ops); (ops) = (ops)->next)
-
-/*
- * If enabled, frontswap_store will return failure even on success. As
- * a result, the swap subsystem will always write the page to swap, in
- * effect converting frontswap into a writethrough cache. In this mode,
- * there is no direct reduction in swap writes, but a frontswap backend
- * can unilaterally "reclaim" any pages in use with no data loss, thus
- * providing increases control over maximum memory usage due to frontswap.
- */
-static bool frontswap_writethrough_enabled __read_mostly;
-
-/*
- * If enabled, the underlying tmem implementation is capable of doing
- * exclusive gets, so frontswap_load, on a successful tmem_get must
- * mark the page as no longer in frontswap AND mark it dirty.
- */
-static bool frontswap_tmem_exclusive_gets_enabled __read_mostly;
+static const struct frontswap_ops *frontswap_ops __read_mostly;
#ifdef CONFIG_DEBUG_FS
/*
@@ -114,87 +94,22 @@ static inline void inc_frontswap_invalidates(void) { }
/*
* Register operations for frontswap
*/
-void frontswap_register_ops(struct frontswap_ops *ops)
+int frontswap_register_ops(const struct frontswap_ops *ops)
{
- DECLARE_BITMAP(a, MAX_SWAPFILES);
- DECLARE_BITMAP(b, MAX_SWAPFILES);
- struct swap_info_struct *si;
- unsigned int i;
-
- bitmap_zero(a, MAX_SWAPFILES);
- bitmap_zero(b, MAX_SWAPFILES);
-
- spin_lock(&swap_lock);
- plist_for_each_entry(si, &swap_active_head, list) {
- if (!WARN_ON(!si->frontswap_map))
- __set_bit(si->type, a);
- }
- spin_unlock(&swap_lock);
-
- /* the new ops needs to know the currently active swap devices */
- for_each_set_bit(i, a, MAX_SWAPFILES)
- ops->init(i);
-
- /*
- * Setting frontswap_ops must happen after the ops->init() calls
- * above; cmpxchg implies smp_mb() which will ensure the init is
- * complete at this point.
- */
- do {
- ops->next = frontswap_ops;
- } while (cmpxchg(&frontswap_ops, ops->next, ops) != ops->next);
+ if (frontswap_ops)
+ return -EINVAL;
+ frontswap_ops = ops;
static_branch_inc(&frontswap_enabled_key);
-
- spin_lock(&swap_lock);
- plist_for_each_entry(si, &swap_active_head, list) {
- if (si->frontswap_map)
- __set_bit(si->type, b);
- }
- spin_unlock(&swap_lock);
-
- /*
- * On the very unlikely chance that a swap device was added or
- * removed between setting the "a" list bits and the ops init
- * calls, we re-check and do init or invalidate for any changed
- * bits.
- */
- if (unlikely(!bitmap_equal(a, b, MAX_SWAPFILES))) {
- for (i = 0; i < MAX_SWAPFILES; i++) {
- if (!test_bit(i, a) && test_bit(i, b))
- ops->init(i);
- else if (test_bit(i, a) && !test_bit(i, b))
- ops->invalidate_area(i);
- }
- }
-}
-EXPORT_SYMBOL(frontswap_register_ops);
-
-/*
- * Enable/disable frontswap writethrough (see above).
- */
-void frontswap_writethrough(bool enable)
-{
- frontswap_writethrough_enabled = enable;
-}
-EXPORT_SYMBOL(frontswap_writethrough);
-
-/*
- * Enable/disable frontswap exclusive gets (see above).
- */
-void frontswap_tmem_exclusive_gets(bool enable)
-{
- frontswap_tmem_exclusive_gets_enabled = enable;
+ return 0;
}
-EXPORT_SYMBOL(frontswap_tmem_exclusive_gets);
/*
* Called when a swap device is swapon'd.
*/
-void __frontswap_init(unsigned type, unsigned long *map)
+void frontswap_init(unsigned type, unsigned long *map)
{
struct swap_info_struct *sis = swap_info[type];
- struct frontswap_ops *ops;
VM_BUG_ON(sis == NULL);
@@ -210,20 +125,16 @@ void __frontswap_init(unsigned type, unsigned long *map)
* p->frontswap set to something valid to work properly.
*/
frontswap_map_set(sis, map);
-
- for_each_frontswap_ops(ops)
- ops->init(type);
+ frontswap_ops->init(type);
}
-EXPORT_SYMBOL(__frontswap_init);
-bool __frontswap_test(struct swap_info_struct *sis,
+static bool __frontswap_test(struct swap_info_struct *sis,
pgoff_t offset)
{
if (sis->frontswap_map)
return test_bit(offset, sis->frontswap_map);
return false;
}
-EXPORT_SYMBOL(__frontswap_test);
static inline void __frontswap_set(struct swap_info_struct *sis,
pgoff_t offset)
@@ -253,7 +164,6 @@ int __frontswap_store(struct page *page)
int type = swp_type(entry);
struct swap_info_struct *sis = swap_info[type];
pgoff_t offset = swp_offset(entry);
- struct frontswap_ops *ops;
VM_BUG_ON(!frontswap_ops);
VM_BUG_ON(!PageLocked(page));
@@ -267,28 +177,19 @@ int __frontswap_store(struct page *page)
*/
if (__frontswap_test(sis, offset)) {
__frontswap_clear(sis, offset);
- for_each_frontswap_ops(ops)
- ops->invalidate_page(type, offset);
+ frontswap_ops->invalidate_page(type, offset);
}
- /* Try to store in each implementation, until one succeeds. */
- for_each_frontswap_ops(ops) {
- ret = ops->store(type, offset, page);
- if (!ret) /* successful store */
- break;
- }
+ ret = frontswap_ops->store(type, offset, page);
if (ret == 0) {
__frontswap_set(sis, offset);
inc_frontswap_succ_stores();
} else {
inc_frontswap_failed_stores();
}
- if (frontswap_writethrough_enabled)
- /* report failure so swap also writes to swap device */
- ret = -1;
+
return ret;
}
-EXPORT_SYMBOL(__frontswap_store);
/*
* "Get" data from frontswap associated with swaptype and offset that were
@@ -302,7 +203,6 @@ int __frontswap_load(struct page *page)
int type = swp_type(entry);
struct swap_info_struct *sis = swap_info[type];
pgoff_t offset = swp_offset(entry);
- struct frontswap_ops *ops;
VM_BUG_ON(!frontswap_ops);
VM_BUG_ON(!PageLocked(page));
@@ -312,21 +212,11 @@ int __frontswap_load(struct page *page)
return -1;
/* Try loading from each implementation, until one succeeds. */
- for_each_frontswap_ops(ops) {
- ret = ops->load(type, offset, page);
- if (!ret) /* successful load */
- break;
- }
- if (ret == 0) {
+ ret = frontswap_ops->load(type, offset, page);
+ if (ret == 0)
inc_frontswap_loads();
- if (frontswap_tmem_exclusive_gets_enabled) {
- SetPageDirty(page);
- __frontswap_clear(sis, offset);
- }
- }
return ret;
}
-EXPORT_SYMBOL(__frontswap_load);
/*
* Invalidate any data from frontswap associated with the specified swaptype
@@ -335,7 +225,6 @@ EXPORT_SYMBOL(__frontswap_load);
void __frontswap_invalidate_page(unsigned type, pgoff_t offset)
{
struct swap_info_struct *sis = swap_info[type];
- struct frontswap_ops *ops;
VM_BUG_ON(!frontswap_ops);
VM_BUG_ON(sis == NULL);
@@ -343,12 +232,10 @@ void __frontswap_invalidate_page(unsigned type, pgoff_t offset)
if (!__frontswap_test(sis, offset))
return;
- for_each_frontswap_ops(ops)
- ops->invalidate_page(type, offset);
+ frontswap_ops->invalidate_page(type, offset);
__frontswap_clear(sis, offset);
inc_frontswap_invalidates();
}
-EXPORT_SYMBOL(__frontswap_invalidate_page);
/*
* Invalidate all data from frontswap associated with all offsets for the
@@ -357,7 +244,6 @@ EXPORT_SYMBOL(__frontswap_invalidate_page);
void __frontswap_invalidate_area(unsigned type)
{
struct swap_info_struct *sis = swap_info[type];
- struct frontswap_ops *ops;
VM_BUG_ON(!frontswap_ops);
VM_BUG_ON(sis == NULL);
@@ -365,123 +251,10 @@ void __frontswap_invalidate_area(unsigned type)
if (sis->frontswap_map == NULL)
return;
- for_each_frontswap_ops(ops)
- ops->invalidate_area(type);
+ frontswap_ops->invalidate_area(type);
atomic_set(&sis->frontswap_pages, 0);
bitmap_zero(sis->frontswap_map, sis->max);
}
-EXPORT_SYMBOL(__frontswap_invalidate_area);
-
-static unsigned long __frontswap_curr_pages(void)
-{
- unsigned long totalpages = 0;
- struct swap_info_struct *si = NULL;
-
- assert_spin_locked(&swap_lock);
- plist_for_each_entry(si, &swap_active_head, list)
- totalpages += atomic_read(&si->frontswap_pages);
- return totalpages;
-}
-
-static int __frontswap_unuse_pages(unsigned long total, unsigned long *unused,
- int *swapid)
-{
- int ret = -EINVAL;
- struct swap_info_struct *si = NULL;
- int si_frontswap_pages;
- unsigned long total_pages_to_unuse = total;
- unsigned long pages = 0, pages_to_unuse = 0;
-
- assert_spin_locked(&swap_lock);
- plist_for_each_entry(si, &swap_active_head, list) {
- si_frontswap_pages = atomic_read(&si->frontswap_pages);
- if (total_pages_to_unuse < si_frontswap_pages) {
- pages = pages_to_unuse = total_pages_to_unuse;
- } else {
- pages = si_frontswap_pages;
- pages_to_unuse = 0; /* unuse all */
- }
- /* ensure there is enough RAM to fetch pages from frontswap */
- if (security_vm_enough_memory_mm(current->mm, pages)) {
- ret = -ENOMEM;
- continue;
- }
- vm_unacct_memory(pages);
- *unused = pages_to_unuse;
- *swapid = si->type;
- ret = 0;
- break;
- }
-
- return ret;
-}
-
-/*
- * Used to check if it's necessary and feasible to unuse pages.
- * Return 1 when nothing to do, 0 when need to shrink pages,
- * error code when there is an error.
- */
-static int __frontswap_shrink(unsigned long target_pages,
- unsigned long *pages_to_unuse,
- int *type)
-{
- unsigned long total_pages = 0, total_pages_to_unuse;
-
- assert_spin_locked(&swap_lock);
-
- total_pages = __frontswap_curr_pages();
- if (total_pages <= target_pages) {
- /* Nothing to do */
- *pages_to_unuse = 0;
- return 1;
- }
- total_pages_to_unuse = total_pages - target_pages;
- return __frontswap_unuse_pages(total_pages_to_unuse, pages_to_unuse, type);
-}
-
-/*
- * Frontswap, like a true swap device, may unnecessarily retain pages
- * under certain circumstances; "shrink" frontswap is essentially a
- * "partial swapoff" and works by calling try_to_unuse to attempt to
- * unuse enough frontswap pages to attempt to -- subject to memory
- * constraints -- reduce the number of pages in frontswap to the
- * number given in the parameter target_pages.
- */
-void frontswap_shrink(unsigned long target_pages)
-{
- unsigned long pages_to_unuse = 0;
- int type, ret;
-
- /*
- * we don't want to hold swap_lock while doing a very
- * lengthy try_to_unuse, but swap_list may change
- * so restart scan from swap_active_head each time
- */
- spin_lock(&swap_lock);
- ret = __frontswap_shrink(target_pages, &pages_to_unuse, &type);
- spin_unlock(&swap_lock);
- if (ret == 0)
- try_to_unuse(type, true, pages_to_unuse);
- return;
-}
-EXPORT_SYMBOL(frontswap_shrink);
-
-/*
- * Count and return the number of frontswap pages across all
- * swap devices. This is exported so that backend drivers can
- * determine current usage without reading debugfs.
- */
-unsigned long frontswap_curr_pages(void)
-{
- unsigned long totalpages = 0;
-
- spin_lock(&swap_lock);
- totalpages = __frontswap_curr_pages();
- spin_unlock(&swap_lock);
-
- return totalpages;
-}
-EXPORT_SYMBOL(frontswap_curr_pages);
static int __init init_frontswap(void)
{
diff --git a/mm/kasan/common.c b/mm/kasan/common.c
index 7c06db78a76c..92196562687b 100644
--- a/mm/kasan/common.c
+++ b/mm/kasan/common.c
@@ -36,7 +36,6 @@ depot_stack_handle_t kasan_save_stack(gfp_t flags, bool can_alloc)
unsigned int nr_entries;
nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 0);
- nr_entries = filter_irq_stacks(entries, nr_entries);
return __stack_depot_save(entries, nr_entries, flags, can_alloc);
}
diff --git a/mm/migrate.c b/mm/migrate.c
index 18ce840914f0..c7da064b4781 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -291,7 +291,6 @@ void __migration_entry_wait(struct mm_struct *mm, pte_t *ptep,
{
pte_t pte;
swp_entry_t entry;
- struct folio *folio;
spin_lock(ptl);
pte = *ptep;
@@ -302,17 +301,7 @@ void __migration_entry_wait(struct mm_struct *mm, pte_t *ptep,
if (!is_migration_entry(entry))
goto out;
- folio = page_folio(pfn_swap_entry_to_page(entry));
-
- /*
- * Once page cache replacement of page migration started, page_count
- * is zero; but we must not call folio_put_wait_locked() without
- * a ref. Use folio_try_get(), and just fault again if it fails.
- */
- if (!folio_try_get(folio))
- goto out;
- pte_unmap_unlock(ptep, ptl);
- folio_put_wait_locked(folio, TASK_UNINTERRUPTIBLE);
+ migration_entry_wait_on_locked(entry, ptep, ptl);
return;
out:
pte_unmap_unlock(ptep, ptl);
@@ -337,16 +326,11 @@ void migration_entry_wait_huge(struct vm_area_struct *vma,
void pmd_migration_entry_wait(struct mm_struct *mm, pmd_t *pmd)
{
spinlock_t *ptl;
- struct folio *folio;
ptl = pmd_lock(mm, pmd);
if (!is_pmd_migration_entry(*pmd))
goto unlock;
- folio = page_folio(pfn_swap_entry_to_page(pmd_to_swp_entry(*pmd)));
- if (!folio_try_get(folio))
- goto unlock;
- spin_unlock(ptl);
- folio_put_wait_locked(folio, TASK_UNINTERRUPTIBLE);
+ migration_entry_wait_on_locked(pmd_to_swp_entry(*pmd), NULL, ptl);
return;
unlock:
spin_unlock(ptl);
@@ -2431,22 +2415,8 @@ static bool migrate_vma_check_page(struct page *page)
return false;
/* Page from ZONE_DEVICE have one extra reference */
- if (is_zone_device_page(page)) {
- /*
- * Private page can never be pin as they have no valid pte and
- * GUP will fail for those. Yet if there is a pending migration
- * a thread might try to wait on the pte migration entry and
- * will bump the page reference count. Sadly there is no way to
- * differentiate a regular pin from migration wait. Hence to
- * avoid 2 racing thread trying to migrate back to CPU to enter
- * infinite loop (one stopping migration because the other is
- * waiting on pte migration entry). We always return true here.
- *
- * FIXME proper solution is to rework migration_entry_wait() so
- * it does not need to take a reference on page.
- */
- return is_device_private_page(page);
- }
+ if (is_zone_device_page(page))
+ extra++;
/* For file back page */
if (page_mapping(page))
diff --git a/mm/page_owner.c b/mm/page_owner.c
index 5eea061bb1e5..99e360df9465 100644
--- a/mm/page_owner.c
+++ b/mm/page_owner.c
@@ -80,6 +80,8 @@ static __init void init_page_owner(void)
if (!page_owner_enabled)
return;
+ stack_depot_init();
+
register_dummy_stack();
register_failure_stack();
register_early_stack();
diff --git a/mm/shmem.c b/mm/shmem.c
index 66909efd0a1b..a09b29ec2b45 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -36,7 +36,6 @@
#include <linux/uio.h>
#include <linux/khugepaged.h>
#include <linux/hugetlb.h>
-#include <linux/frontswap.h>
#include <linux/fs_parser.h>
#include <linux/swapfile.h>
@@ -1152,7 +1151,7 @@ static void shmem_evict_inode(struct inode *inode)
static int shmem_find_swap_entries(struct address_space *mapping,
pgoff_t start, unsigned int nr_entries,
struct page **entries, pgoff_t *indices,
- unsigned int type, bool frontswap)
+ unsigned int type)
{
XA_STATE(xas, &mapping->i_pages, start);
struct page *page;
@@ -1173,9 +1172,6 @@ static int shmem_find_swap_entries(struct address_space *mapping,
entry = radix_to_swp_entry(page);
if (swp_type(entry) != type)
continue;
- if (frontswap &&
- !frontswap_test(swap_info[type], swp_offset(entry)))
- continue;
indices[ret] = xas.xa_index;
entries[ret] = page;
@@ -1228,26 +1224,20 @@ static int shmem_unuse_swap_entries(struct inode *inode, struct pagevec pvec,
/*
* If swap found in inode, free it and move page from swapcache to filecache.
*/
-static int shmem_unuse_inode(struct inode *inode, unsigned int type,
- bool frontswap, unsigned long *fs_pages_to_unuse)
+static int shmem_unuse_inode(struct inode *inode, unsigned int type)
{
struct address_space *mapping = inode->i_mapping;
pgoff_t start = 0;
struct pagevec pvec;
pgoff_t indices[PAGEVEC_SIZE];
- bool frontswap_partial = (frontswap && *fs_pages_to_unuse > 0);
int ret = 0;
pagevec_init(&pvec);
do {
unsigned int nr_entries = PAGEVEC_SIZE;
- if (frontswap_partial && *fs_pages_to_unuse < PAGEVEC_SIZE)
- nr_entries = *fs_pages_to_unuse;
-
pvec.nr = shmem_find_swap_entries(mapping, start, nr_entries,
- pvec.pages, indices,
- type, frontswap);
+ pvec.pages, indices, type);
if (pvec.nr == 0) {
ret = 0;
break;
@@ -1257,14 +1247,6 @@ static int shmem_unuse_inode(struct inode *inode, unsigned int type,
if (ret < 0)
break;
- if (frontswap_partial) {
- *fs_pages_to_unuse -= ret;
- if (*fs_pages_to_unuse == 0) {
- ret = FRONTSWAP_PAGES_UNUSED;
- break;
- }
- }
-
start = indices[pvec.nr - 1];
} while (true);
@@ -1276,8 +1258,7 @@ static int shmem_unuse_inode(struct inode *inode, unsigned int type,
* device 'type' back into memory, so the swap device can be
* unused.
*/
-int shmem_unuse(unsigned int type, bool frontswap,
- unsigned long *fs_pages_to_unuse)
+int shmem_unuse(unsigned int type)
{
struct shmem_inode_info *info, *next;
int error = 0;
@@ -1300,8 +1281,7 @@ int shmem_unuse(unsigned int type, bool frontswap,
atomic_inc(&info->stop_eviction);
mutex_unlock(&shmem_swaplist_mutex);
- error = shmem_unuse_inode(&info->vfs_inode, type, frontswap,
- fs_pages_to_unuse);
+ error = shmem_unuse_inode(&info->vfs_inode, type);
cond_resched();
mutex_lock(&shmem_swaplist_mutex);
@@ -4015,8 +3995,7 @@ int __init shmem_init(void)
return 0;
}
-int shmem_unuse(unsigned int type, bool frontswap,
- unsigned long *fs_pages_to_unuse)
+int shmem_unuse(unsigned int type)
{
return 0;
}
diff --git a/mm/swapfile.c b/mm/swapfile.c
index caa9f81a0d15..bf0df7aa7158 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -49,7 +49,7 @@ static bool swap_count_continued(struct swap_info_struct *, pgoff_t,
unsigned char);
static void free_swap_count_continuations(struct swap_info_struct *);
-DEFINE_SPINLOCK(swap_lock);
+static DEFINE_SPINLOCK(swap_lock);
static unsigned int nr_swapfiles;
atomic_long_t nr_swap_pages;
/*
@@ -71,7 +71,7 @@ static const char Unused_offset[] = "Unused swap offset entry ";
* all active swap_info_structs
* protected with swap_lock, and ordered by priority.
*/
-PLIST_HEAD(swap_active_head);
+static PLIST_HEAD(swap_active_head);
/*
* all available (active, not full) swap_info_structs
@@ -1923,8 +1923,7 @@ out:
static int unuse_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
unsigned long addr, unsigned long end,
- unsigned int type, bool frontswap,
- unsigned long *fs_pages_to_unuse)
+ unsigned int type)
{
struct page *page;
swp_entry_t entry;
@@ -1945,9 +1944,6 @@ static int unuse_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
continue;
offset = swp_offset(entry);
- if (frontswap && !frontswap_test(si, offset))
- continue;
-
pte_unmap(pte);
swap_map = &si->swap_map[offset];
page = lookup_swap_cache(entry, vma, addr);
@@ -1979,11 +1975,6 @@ static int unuse_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
try_to_free_swap(page);
unlock_page(page);
put_page(page);
-
- if (*fs_pages_to_unuse && !--(*fs_pages_to_unuse)) {
- ret = FRONTSWAP_PAGES_UNUSED;
- goto out;
- }
try_next:
pte = pte_offset_map(pmd, addr);
} while (pte++, addr += PAGE_SIZE, addr != end);
@@ -1996,8 +1987,7 @@ out:
static inline int unuse_pmd_range(struct vm_area_struct *vma, pud_t *pud,
unsigned long addr, unsigned long end,
- unsigned int type, bool frontswap,
- unsigned long *fs_pages_to_unuse)
+ unsigned int type)
{
pmd_t *pmd;
unsigned long next;
@@ -2009,8 +1999,7 @@ static inline int unuse_pmd_range(struct vm_area_struct *vma, pud_t *pud,
next = pmd_addr_end(addr, end);
if (pmd_none_or_trans_huge_or_clear_bad(pmd))
continue;
- ret = unuse_pte_range(vma, pmd, addr, next, type,
- frontswap, fs_pages_to_unuse);
+ ret = unuse_pte_range(vma, pmd, addr, next, type);
if (ret)
return ret;
} while (pmd++, addr = next, addr != end);
@@ -2019,8 +2008,7 @@ static inline int unuse_pmd_range(struct vm_area_struct *vma, pud_t *pud,
static inline int unuse_pud_range(struct vm_area_struct *vma, p4d_t *p4d,
unsigned long addr, unsigned long end,
- unsigned int type, bool frontswap,
- unsigned long *fs_pages_to_unuse)
+ unsigned int type)
{
pud_t *pud;
unsigned long next;
@@ -2031,8 +2019,7 @@ static inline int unuse_pud_range(struct vm_area_struct *vma, p4d_t *p4d,
next = pud_addr_end(addr, end);
if (pud_none_or_clear_bad(pud))
continue;
- ret = unuse_pmd_range(vma, pud, addr, next, type,
- frontswap, fs_pages_to_unuse);
+ ret = unuse_pmd_range(vma, pud, addr, next, type);
if (ret)
return ret;
} while (pud++, addr = next, addr != end);
@@ -2041,8 +2028,7 @@ static inline int unuse_pud_range(struct vm_area_struct *vma, p4d_t *p4d,
static inline int unuse_p4d_range(struct vm_area_struct *vma, pgd_t *pgd,
unsigned long addr, unsigned long end,
- unsigned int type, bool frontswap,
- unsigned long *fs_pages_to_unuse)
+ unsigned int type)
{
p4d_t *p4d;
unsigned long next;
@@ -2053,16 +2039,14 @@ static inline int unuse_p4d_range(struct vm_area_struct *vma, pgd_t *pgd,
next = p4d_addr_end(addr, end);
if (p4d_none_or_clear_bad(p4d))
continue;
- ret = unuse_pud_range(vma, p4d, addr, next, type,
- frontswap, fs_pages_to_unuse);
+ ret = unuse_pud_range(vma, p4d, addr, next, type);
if (ret)
return ret;
} while (p4d++, addr = next, addr != end);
return 0;
}
-static int unuse_vma(struct vm_area_struct *vma, unsigned int type,
- bool frontswap, unsigned long *fs_pages_to_unuse)
+static int unuse_vma(struct vm_area_struct *vma, unsigned int type)
{
pgd_t *pgd;
unsigned long addr, end, next;
@@ -2076,16 +2060,14 @@ static int unuse_vma(struct vm_area_struct *vma, unsigned int type,
next = pgd_addr_end(addr, end);
if (pgd_none_or_clear_bad(pgd))
continue;
- ret = unuse_p4d_range(vma, pgd, addr, next, type,
- frontswap, fs_pages_to_unuse);
+ ret = unuse_p4d_range(vma, pgd, addr, next, type);
if (ret)
return ret;
} while (pgd++, addr = next, addr != end);
return 0;
}
-static int unuse_mm(struct mm_struct *mm, unsigned int type,
- bool frontswap, unsigned long *fs_pages_to_unuse)
+static int unuse_mm(struct mm_struct *mm, unsigned int type)
{
struct vm_area_struct *vma;
int ret = 0;
@@ -2093,8 +2075,7 @@ static int unuse_mm(struct mm_struct *mm, unsigned int type,
mmap_read_lock(mm);
for (vma = mm->mmap; vma; vma = vma->vm_next) {
if (vma->anon_vma) {
- ret = unuse_vma(vma, type, frontswap,
- fs_pages_to_unuse);
+ ret = unuse_vma(vma, type);
if (ret)
break;
}
@@ -2110,7 +2091,7 @@ static int unuse_mm(struct mm_struct *mm, unsigned int type,
* 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, bool frontswap)
+ unsigned int prev)
{
unsigned int i;
unsigned char count;
@@ -2124,8 +2105,7 @@ static unsigned int find_next_to_unuse(struct swap_info_struct *si,
for (i = prev + 1; i < si->max; i++) {
count = READ_ONCE(si->swap_map[i]);
if (count && swap_count(count) != SWAP_MAP_BAD)
- if (!frontswap || frontswap_test(si, i))
- break;
+ break;
if ((i % LATENCY_LIMIT) == 0)
cond_resched();
}
@@ -2136,12 +2116,7 @@ static unsigned int find_next_to_unuse(struct swap_info_struct *si,
return i;
}
-/*
- * If the boolean frontswap is true, only unuse pages_to_unuse pages;
- * pages_to_unuse==0 means all pages; ignored if frontswap is false
- */
-int try_to_unuse(unsigned int type, bool frontswap,
- unsigned long pages_to_unuse)
+static int try_to_unuse(unsigned int type)
{
struct mm_struct *prev_mm;
struct mm_struct *mm;
@@ -2155,13 +2130,10 @@ int try_to_unuse(unsigned int type, bool frontswap,
if (!READ_ONCE(si->inuse_pages))
return 0;
- if (!frontswap)
- pages_to_unuse = 0;
-
retry:
- retval = shmem_unuse(type, frontswap, &pages_to_unuse);
+ retval = shmem_unuse(type);
if (retval)
- goto out;
+ return retval;
prev_mm = &init_mm;
mmget(prev_mm);
@@ -2178,11 +2150,10 @@ retry:
spin_unlock(&mmlist_lock);
mmput(prev_mm);
prev_mm = mm;
- retval = unuse_mm(mm, type, frontswap, &pages_to_unuse);
-
+ retval = unuse_mm(mm, type);
if (retval) {
mmput(prev_mm);
- goto out;
+ return retval;
}
/*
@@ -2199,7 +2170,7 @@ retry:
i = 0;
while (READ_ONCE(si->inuse_pages) &&
!signal_pending(current) &&
- (i = find_next_to_unuse(si, i, frontswap)) != 0) {
+ (i = find_next_to_unuse(si, i)) != 0) {
entry = swp_entry(type, i);
page = find_get_page(swap_address_space(entry), i);
@@ -2217,14 +2188,6 @@ retry:
try_to_free_swap(page);
unlock_page(page);
put_page(page);
-
- /*
- * For frontswap, we just need to unuse pages_to_unuse, if
- * it was specified. Need not check frontswap again here as
- * we already zeroed out pages_to_unuse if not frontswap.
- */
- if (pages_to_unuse && --pages_to_unuse == 0)
- goto out;
}
/*
@@ -2242,10 +2205,10 @@ retry:
if (READ_ONCE(si->inuse_pages)) {
if (!signal_pending(current))
goto retry;
- retval = -EINTR;
+ return -EINTR;
}
-out:
- return (retval == FRONTSWAP_PAGES_UNUSED) ? 0 : retval;
+
+ return 0;
}
/*
@@ -2463,7 +2426,8 @@ static void enable_swap_info(struct swap_info_struct *p, int prio,
struct swap_cluster_info *cluster_info,
unsigned long *frontswap_map)
{
- frontswap_init(p->type, frontswap_map);
+ if (IS_ENABLED(CONFIG_FRONTSWAP))
+ frontswap_init(p->type, frontswap_map);
spin_lock(&swap_lock);
spin_lock(&p->lock);
setup_swap_info(p, prio, swap_map, cluster_info);
@@ -2576,7 +2540,7 @@ SYSCALL_DEFINE1(swapoff, const char __user *, specialfile)
disable_swap_slots_cache_lock();
set_current_oom_origin();
- err = try_to_unuse(p->type, false, 0); /* force unuse all pages */
+ err = try_to_unuse(p->type);
clear_current_oom_origin();
if (err) {
diff --git a/mm/truncate.c b/mm/truncate.c
index 5e243d7269c0..9dbf0b75da5d 100644
--- a/mm/truncate.c
+++ b/mm/truncate.c
@@ -22,7 +22,6 @@
#include <linux/buffer_head.h> /* grr. try_to_release_page,
do_invalidatepage */
#include <linux/shmem_fs.h>
-#include <linux/cleancache.h>
#include <linux/rmap.h>
#include "internal.h"
@@ -264,7 +263,6 @@ bool truncate_inode_partial_folio(struct folio *folio, loff_t start, loff_t end)
*/
folio_zero_range(folio, offset, length);
- cleancache_invalidate_page(folio->mapping, &folio->page);
if (folio_has_private(folio))
do_invalidatepage(&folio->page, offset, length);
if (!folio_test_large(folio))
@@ -351,7 +349,7 @@ void truncate_inode_pages_range(struct address_space *mapping,
bool same_folio;
if (mapping_empty(mapping))
- goto out;
+ return;
/*
* 'start' and 'end' always covers the range of pages to be fully
@@ -442,9 +440,6 @@ void truncate_inode_pages_range(struct address_space *mapping,
folio_batch_release(&fbatch);
index++;
}
-
-out:
- cleancache_invalidate_inode(mapping);
}
EXPORT_SYMBOL(truncate_inode_pages_range);
@@ -498,10 +493,6 @@ void truncate_inode_pages_final(struct address_space *mapping)
xa_unlock_irq(&mapping->i_pages);
}
- /*
- * Cleancache needs notification even if there are no pages or shadow
- * entries.
- */
truncate_inode_pages(mapping, 0);
}
EXPORT_SYMBOL(truncate_inode_pages_final);
@@ -661,7 +652,7 @@ int invalidate_inode_pages2_range(struct address_space *mapping,
int did_range_unmap = 0;
if (mapping_empty(mapping))
- goto out;
+ return 0;
folio_batch_init(&fbatch);
index = start;
@@ -725,8 +716,6 @@ int invalidate_inode_pages2_range(struct address_space *mapping,
if (dax_mapping(mapping)) {
unmap_mapping_pages(mapping, start, end - start + 1, false);
}
-out:
- cleancache_invalidate_inode(mapping);
return ret;
}
EXPORT_SYMBOL_GPL(invalidate_inode_pages2_range);
diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index 0d3b65939016..9152fbde33b5 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -30,6 +30,14 @@
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+/*
+ * lock ordering:
+ * page_lock
+ * pool->migrate_lock
+ * class->lock
+ * zspage->lock
+ */
+
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/sched.h>
@@ -57,6 +65,7 @@
#include <linux/wait.h>
#include <linux/pagemap.h>
#include <linux/fs.h>
+#include <linux/local_lock.h>
#define ZSPAGE_MAGIC 0x58
@@ -101,15 +110,6 @@
#define _PFN_BITS (MAX_POSSIBLE_PHYSMEM_BITS - PAGE_SHIFT)
/*
- * Memory for allocating for handle keeps object position by
- * encoding <page, obj_idx> and the encoded value has a room
- * in least bit(ie, look at obj_to_location).
- * We use the bit to synchronize between object access by
- * user and migration.
- */
-#define HANDLE_PIN_BIT 0
-
-/*
* Head in allocated object should have OBJ_ALLOCATED_TAG
* to identify the object was allocated or not.
* It's okay to add the status bit in the least bit because
@@ -121,6 +121,7 @@
#define OBJ_INDEX_BITS (BITS_PER_LONG - _PFN_BITS - OBJ_TAG_BITS)
#define OBJ_INDEX_MASK ((_AC(1, UL) << OBJ_INDEX_BITS) - 1)
+#define HUGE_BITS 1
#define FULLNESS_BITS 2
#define CLASS_BITS 8
#define ISOLATED_BITS 3
@@ -158,7 +159,7 @@ enum fullness_group {
NR_ZS_FULLNESS,
};
-enum zs_stat_type {
+enum class_stat_type {
CLASS_EMPTY,
CLASS_ALMOST_EMPTY,
CLASS_ALMOST_FULL,
@@ -213,22 +214,6 @@ struct size_class {
struct zs_size_stat stats;
};
-/* huge object: pages_per_zspage == 1 && maxobj_per_zspage == 1 */
-static void SetPageHugeObject(struct page *page)
-{
- SetPageOwnerPriv1(page);
-}
-
-static void ClearPageHugeObject(struct page *page)
-{
- ClearPageOwnerPriv1(page);
-}
-
-static int PageHugeObject(struct page *page)
-{
- return PageOwnerPriv1(page);
-}
-
/*
* Placed within free objects to form a singly linked list.
* For every zspage, zspage->freeobj gives head of this list.
@@ -269,15 +254,14 @@ struct zs_pool {
#ifdef CONFIG_COMPACTION
struct inode *inode;
struct work_struct free_work;
- /* A wait queue for when migration races with async_free_zspage() */
- struct wait_queue_head migration_wait;
- atomic_long_t isolated_pages;
- bool destroying;
#endif
+ /* protect page/zspage migration */
+ rwlock_t migrate_lock;
};
struct zspage {
struct {
+ unsigned int huge:HUGE_BITS;
unsigned int fullness:FULLNESS_BITS;
unsigned int class:CLASS_BITS + 1;
unsigned int isolated:ISOLATED_BITS;
@@ -293,17 +277,32 @@ struct zspage {
};
struct mapping_area {
+ local_lock_t lock;
char *vm_buf; /* copy buffer for objects that span pages */
char *vm_addr; /* address of kmap_atomic()'ed pages */
enum zs_mapmode vm_mm; /* mapping mode */
};
+/* huge object: pages_per_zspage == 1 && maxobj_per_zspage == 1 */
+static void SetZsHugePage(struct zspage *zspage)
+{
+ zspage->huge = 1;
+}
+
+static bool ZsHugePage(struct zspage *zspage)
+{
+ return zspage->huge;
+}
+
#ifdef CONFIG_COMPACTION
static int zs_register_migration(struct zs_pool *pool);
static void zs_unregister_migration(struct zs_pool *pool);
static void migrate_lock_init(struct zspage *zspage);
static void migrate_read_lock(struct zspage *zspage);
static void migrate_read_unlock(struct zspage *zspage);
+static void migrate_write_lock(struct zspage *zspage);
+static void migrate_write_lock_nested(struct zspage *zspage);
+static void migrate_write_unlock(struct zspage *zspage);
static void kick_deferred_free(struct zs_pool *pool);
static void init_deferred_free(struct zs_pool *pool);
static void SetZsPageMovable(struct zs_pool *pool, struct zspage *zspage);
@@ -315,6 +314,9 @@ static void zs_unregister_migration(struct zs_pool *pool) {}
static void migrate_lock_init(struct zspage *zspage) {}
static void migrate_read_lock(struct zspage *zspage) {}
static void migrate_read_unlock(struct zspage *zspage) {}
+static void migrate_write_lock(struct zspage *zspage) {}
+static void migrate_write_lock_nested(struct zspage *zspage) {}
+static void migrate_write_unlock(struct zspage *zspage) {}
static void kick_deferred_free(struct zs_pool *pool) {}
static void init_deferred_free(struct zs_pool *pool) {}
static void SetZsPageMovable(struct zs_pool *pool, struct zspage *zspage) {}
@@ -366,14 +368,10 @@ static void cache_free_zspage(struct zs_pool *pool, struct zspage *zspage)
kmem_cache_free(pool->zspage_cachep, zspage);
}
+/* class->lock(which owns the handle) synchronizes races */
static void record_obj(unsigned long handle, unsigned long obj)
{
- /*
- * lsb of @obj represents handle lock while other bits
- * represent object value the handle is pointing so
- * updating shouldn't do store tearing.
- */
- WRITE_ONCE(*(unsigned long *)handle, obj);
+ *(unsigned long *)handle = obj;
}
/* zpool driver */
@@ -455,12 +453,9 @@ MODULE_ALIAS("zpool-zsmalloc");
#endif /* CONFIG_ZPOOL */
/* per-cpu VM mapping areas for zspage accesses that cross page boundaries */
-static DEFINE_PER_CPU(struct mapping_area, zs_map_area);
-
-static bool is_zspage_isolated(struct zspage *zspage)
-{
- return zspage->isolated;
-}
+static DEFINE_PER_CPU(struct mapping_area, zs_map_area) = {
+ .lock = INIT_LOCAL_LOCK(lock),
+};
static __maybe_unused int is_first_page(struct page *page)
{
@@ -517,6 +512,12 @@ static void get_zspage_mapping(struct zspage *zspage,
*class_idx = zspage->class;
}
+static struct size_class *zspage_class(struct zs_pool *pool,
+ struct zspage *zspage)
+{
+ return pool->size_class[zspage->class];
+}
+
static void set_zspage_mapping(struct zspage *zspage,
unsigned int class_idx,
enum fullness_group fullness)
@@ -543,21 +544,21 @@ static int get_size_class_index(int size)
return min_t(int, ZS_SIZE_CLASSES - 1, idx);
}
-/* type can be of enum type zs_stat_type or fullness_group */
-static inline void zs_stat_inc(struct size_class *class,
+/* type can be of enum type class_stat_type or fullness_group */
+static inline void class_stat_inc(struct size_class *class,
int type, unsigned long cnt)
{
class->stats.objs[type] += cnt;
}
-/* type can be of enum type zs_stat_type or fullness_group */
-static inline void zs_stat_dec(struct size_class *class,
+/* type can be of enum type class_stat_type or fullness_group */
+static inline void class_stat_dec(struct size_class *class,
int type, unsigned long cnt)
{
class->stats.objs[type] -= cnt;
}
-/* type can be of enum type zs_stat_type or fullness_group */
+/* type can be of enum type class_stat_type or fullness_group */
static inline unsigned long zs_stat_get(struct size_class *class,
int type)
{
@@ -719,7 +720,7 @@ static void insert_zspage(struct size_class *class,
{
struct zspage *head;
- zs_stat_inc(class, fullness, 1);
+ class_stat_inc(class, fullness, 1);
head = list_first_entry_or_null(&class->fullness_list[fullness],
struct zspage, list);
/*
@@ -741,10 +742,9 @@ static void remove_zspage(struct size_class *class,
enum fullness_group fullness)
{
VM_BUG_ON(list_empty(&class->fullness_list[fullness]));
- VM_BUG_ON(is_zspage_isolated(zspage));
list_del_init(&zspage->list);
- zs_stat_dec(class, fullness, 1);
+ class_stat_dec(class, fullness, 1);
}
/*
@@ -767,13 +767,9 @@ static enum fullness_group fix_fullness_group(struct size_class *class,
if (newfg == currfg)
goto out;
- if (!is_zspage_isolated(zspage)) {
- remove_zspage(class, zspage, currfg);
- insert_zspage(class, zspage, newfg);
- }
-
+ remove_zspage(class, zspage, currfg);
+ insert_zspage(class, zspage, newfg);
set_zspage_mapping(zspage, class_idx, newfg);
-
out:
return newfg;
}
@@ -824,7 +820,9 @@ static struct zspage *get_zspage(struct page *page)
static struct page *get_next_page(struct page *page)
{
- if (unlikely(PageHugeObject(page)))
+ struct zspage *zspage = get_zspage(page);
+
+ if (unlikely(ZsHugePage(zspage)))
return NULL;
return (struct page *)page->index;
@@ -844,6 +842,12 @@ static void obj_to_location(unsigned long obj, struct page **page,
*obj_idx = (obj & OBJ_INDEX_MASK);
}
+static void obj_to_page(unsigned long obj, struct page **page)
+{
+ obj >>= OBJ_TAG_BITS;
+ *page = pfn_to_page(obj >> OBJ_INDEX_BITS);
+}
+
/**
* location_to_obj - get obj value encoded from (<page>, <obj_idx>)
* @page: page object resides in zspage
@@ -865,33 +869,22 @@ static unsigned long handle_to_obj(unsigned long handle)
return *(unsigned long *)handle;
}
-static unsigned long obj_to_head(struct page *page, void *obj)
+static bool obj_allocated(struct page *page, void *obj, unsigned long *phandle)
{
- if (unlikely(PageHugeObject(page))) {
+ unsigned long handle;
+ struct zspage *zspage = get_zspage(page);
+
+ if (unlikely(ZsHugePage(zspage))) {
VM_BUG_ON_PAGE(!is_first_page(page), page);
- return page->index;
+ handle = page->index;
} else
- return *(unsigned long *)obj;
-}
-
-static inline int testpin_tag(unsigned long handle)
-{
- return bit_spin_is_locked(HANDLE_PIN_BIT, (unsigned long *)handle);
-}
-
-static inline int trypin_tag(unsigned long handle)
-{
- return bit_spin_trylock(HANDLE_PIN_BIT, (unsigned long *)handle);
-}
+ handle = *(unsigned long *)obj;
-static void pin_tag(unsigned long handle) __acquires(bitlock)
-{
- bit_spin_lock(HANDLE_PIN_BIT, (unsigned long *)handle);
-}
+ if (!(handle & OBJ_ALLOCATED_TAG))
+ return false;
-static void unpin_tag(unsigned long handle) __releases(bitlock)
-{
- bit_spin_unlock(HANDLE_PIN_BIT, (unsigned long *)handle);
+ *phandle = handle & ~OBJ_ALLOCATED_TAG;
+ return true;
}
static void reset_page(struct page *page)
@@ -900,7 +893,6 @@ static void reset_page(struct page *page)
ClearPagePrivate(page);
set_page_private(page, 0);
page_mapcount_reset(page);
- ClearPageHugeObject(page);
page->index = 0;
}
@@ -952,7 +944,7 @@ static void __free_zspage(struct zs_pool *pool, struct size_class *class,
cache_free_zspage(pool, zspage);
- zs_stat_dec(class, OBJ_ALLOCATED, class->objs_per_zspage);
+ class_stat_dec(class, OBJ_ALLOCATED, class->objs_per_zspage);
atomic_long_sub(class->pages_per_zspage,
&pool->pages_allocated);
}
@@ -963,6 +955,11 @@ static void free_zspage(struct zs_pool *pool, struct size_class *class,
VM_BUG_ON(get_zspage_inuse(zspage));
VM_BUG_ON(list_empty(&zspage->list));
+ /*
+ * Since zs_free couldn't be sleepable, this function cannot call
+ * lock_page. The page locks trylock_zspage got will be released
+ * by __free_zspage.
+ */
if (!trylock_zspage(zspage)) {
kick_deferred_free(pool);
return;
@@ -1042,7 +1039,7 @@ static void create_page_chain(struct size_class *class, struct zspage *zspage,
SetPagePrivate(page);
if (unlikely(class->objs_per_zspage == 1 &&
class->pages_per_zspage == 1))
- SetPageHugeObject(page);
+ SetZsHugePage(zspage);
} else {
prev_page->index = (unsigned long)page;
}
@@ -1246,8 +1243,6 @@ void *zs_map_object(struct zs_pool *pool, unsigned long handle,
unsigned long obj, off;
unsigned int obj_idx;
- unsigned int class_idx;
- enum fullness_group fg;
struct size_class *class;
struct mapping_area *area;
struct page *pages[2];
@@ -1260,21 +1255,26 @@ void *zs_map_object(struct zs_pool *pool, unsigned long handle,
*/
BUG_ON(in_interrupt());
- /* From now on, migration cannot move the object */
- pin_tag(handle);
-
+ /* It guarantees it can get zspage from handle safely */
+ read_lock(&pool->migrate_lock);
obj = handle_to_obj(handle);
obj_to_location(obj, &page, &obj_idx);
zspage = get_zspage(page);
- /* migration cannot move any subpage in this zspage */
+ /*
+ * migration cannot move any zpages in this zspage. Here, class->lock
+ * is too heavy since callers would take some time until they calls
+ * zs_unmap_object API so delegate the locking from class to zspage
+ * which is smaller granularity.
+ */
migrate_read_lock(zspage);
+ read_unlock(&pool->migrate_lock);
- get_zspage_mapping(zspage, &class_idx, &fg);
- class = pool->size_class[class_idx];
+ class = zspage_class(pool, zspage);
off = (class->size * obj_idx) & ~PAGE_MASK;
- area = &get_cpu_var(zs_map_area);
+ local_lock(&zs_map_area.lock);
+ area = this_cpu_ptr(&zs_map_area);
area->vm_mm = mm;
if (off + class->size <= PAGE_SIZE) {
/* this object is contained entirely within a page */
@@ -1290,7 +1290,7 @@ void *zs_map_object(struct zs_pool *pool, unsigned long handle,
ret = __zs_map_object(area, pages, off, class->size);
out:
- if (likely(!PageHugeObject(page)))
+ if (likely(!ZsHugePage(zspage)))
ret += ZS_HANDLE_SIZE;
return ret;
@@ -1304,16 +1304,13 @@ void zs_unmap_object(struct zs_pool *pool, unsigned long handle)
unsigned long obj, off;
unsigned int obj_idx;
- unsigned int class_idx;
- enum fullness_group fg;
struct size_class *class;
struct mapping_area *area;
obj = handle_to_obj(handle);
obj_to_location(obj, &page, &obj_idx);
zspage = get_zspage(page);
- get_zspage_mapping(zspage, &class_idx, &fg);
- class = pool->size_class[class_idx];
+ class = zspage_class(pool, zspage);
off = (class->size * obj_idx) & ~PAGE_MASK;
area = this_cpu_ptr(&zs_map_area);
@@ -1328,10 +1325,9 @@ void zs_unmap_object(struct zs_pool *pool, unsigned long handle)
__zs_unmap_object(area, pages, off, class->size);
}
- put_cpu_var(zs_map_area);
+ local_unlock(&zs_map_area.lock);
migrate_read_unlock(zspage);
- unpin_tag(handle);
}
EXPORT_SYMBOL_GPL(zs_unmap_object);
@@ -1354,17 +1350,19 @@ size_t zs_huge_class_size(struct zs_pool *pool)
}
EXPORT_SYMBOL_GPL(zs_huge_class_size);
-static unsigned long obj_malloc(struct size_class *class,
+static unsigned long obj_malloc(struct zs_pool *pool,
struct zspage *zspage, unsigned long handle)
{
int i, nr_page, offset;
unsigned long obj;
struct link_free *link;
+ struct size_class *class;
struct page *m_page;
unsigned long m_offset;
void *vaddr;
+ class = pool->size_class[zspage->class];
handle |= OBJ_ALLOCATED_TAG;
obj = get_freeobj(zspage);
@@ -1379,7 +1377,7 @@ static unsigned long obj_malloc(struct size_class *class,
vaddr = kmap_atomic(m_page);
link = (struct link_free *)vaddr + m_offset / sizeof(*link);
set_freeobj(zspage, link->next >> OBJ_TAG_BITS);
- if (likely(!PageHugeObject(m_page)))
+ if (likely(!ZsHugePage(zspage)))
/* record handle in the header of allocated chunk */
link->handle = handle;
else
@@ -1388,7 +1386,6 @@ static unsigned long obj_malloc(struct size_class *class,
kunmap_atomic(vaddr);
mod_zspage_inuse(zspage, 1);
- zs_stat_inc(class, OBJ_USED, 1);
obj = location_to_obj(m_page, obj);
@@ -1424,13 +1421,15 @@ unsigned long zs_malloc(struct zs_pool *pool, size_t size, gfp_t gfp)
size += ZS_HANDLE_SIZE;
class = pool->size_class[get_size_class_index(size)];
+ /* class->lock effectively protects the zpage migration */
spin_lock(&class->lock);
zspage = find_get_zspage(class);
if (likely(zspage)) {
- obj = obj_malloc(class, zspage, handle);
+ obj = obj_malloc(pool, zspage, handle);
/* Now move the zspage to another fullness group, if required */
fix_fullness_group(class, zspage);
record_obj(handle, obj);
+ class_stat_inc(class, OBJ_USED, 1);
spin_unlock(&class->lock);
return handle;
@@ -1445,14 +1444,15 @@ unsigned long zs_malloc(struct zs_pool *pool, size_t size, gfp_t gfp)
}
spin_lock(&class->lock);
- obj = obj_malloc(class, zspage, handle);
+ obj = obj_malloc(pool, zspage, handle);
newfg = get_fullness_group(class, zspage);
insert_zspage(class, zspage, newfg);
set_zspage_mapping(zspage, class->index, newfg);
record_obj(handle, obj);
atomic_long_add(class->pages_per_zspage,
&pool->pages_allocated);
- zs_stat_inc(class, OBJ_ALLOCATED, class->objs_per_zspage);
+ class_stat_inc(class, OBJ_ALLOCATED, class->objs_per_zspage);
+ class_stat_inc(class, OBJ_USED, 1);
/* We completely set up zspage so mark them as movable */
SetZsPageMovable(pool, zspage);
@@ -1462,7 +1462,7 @@ unsigned long zs_malloc(struct zs_pool *pool, size_t size, gfp_t gfp)
}
EXPORT_SYMBOL_GPL(zs_malloc);
-static void obj_free(struct size_class *class, unsigned long obj)
+static void obj_free(int class_size, unsigned long obj)
{
struct link_free *link;
struct zspage *zspage;
@@ -1472,18 +1472,20 @@ static void obj_free(struct size_class *class, unsigned long obj)
void *vaddr;
obj_to_location(obj, &f_page, &f_objidx);
- f_offset = (class->size * f_objidx) & ~PAGE_MASK;
+ f_offset = (class_size * f_objidx) & ~PAGE_MASK;
zspage = get_zspage(f_page);
vaddr = kmap_atomic(f_page);
/* Insert this object in containing zspage's freelist */
link = (struct link_free *)(vaddr + f_offset);
- link->next = get_freeobj(zspage) << OBJ_TAG_BITS;
+ if (likely(!ZsHugePage(zspage)))
+ link->next = get_freeobj(zspage) << OBJ_TAG_BITS;
+ else
+ f_page->index = 0;
kunmap_atomic(vaddr);
set_freeobj(zspage, f_objidx);
mod_zspage_inuse(zspage, -1);
- zs_stat_dec(class, OBJ_USED, 1);
}
void zs_free(struct zs_pool *pool, unsigned long handle)
@@ -1491,42 +1493,33 @@ void zs_free(struct zs_pool *pool, unsigned long handle)
struct zspage *zspage;
struct page *f_page;
unsigned long obj;
- unsigned int f_objidx;
- int class_idx;
struct size_class *class;
enum fullness_group fullness;
- bool isolated;
if (unlikely(!handle))
return;
- pin_tag(handle);
+ /*
+ * The pool->migrate_lock protects the race with zpage's migration
+ * so it's safe to get the page from handle.
+ */
+ read_lock(&pool->migrate_lock);
obj = handle_to_obj(handle);
- obj_to_location(obj, &f_page, &f_objidx);
+ obj_to_page(obj, &f_page);
zspage = get_zspage(f_page);
-
- migrate_read_lock(zspage);
-
- get_zspage_mapping(zspage, &class_idx, &fullness);
- class = pool->size_class[class_idx];
-
+ class = zspage_class(pool, zspage);
spin_lock(&class->lock);
- obj_free(class, obj);
+ read_unlock(&pool->migrate_lock);
+
+ obj_free(class->size, obj);
+ class_stat_dec(class, OBJ_USED, 1);
fullness = fix_fullness_group(class, zspage);
- if (fullness != ZS_EMPTY) {
- migrate_read_unlock(zspage);
+ if (fullness != ZS_EMPTY)
goto out;
- }
- isolated = is_zspage_isolated(zspage);
- migrate_read_unlock(zspage);
- /* If zspage is isolated, zs_page_putback will free the zspage */
- if (likely(!isolated))
- free_zspage(pool, class, zspage);
+ free_zspage(pool, class, zspage);
out:
-
spin_unlock(&class->lock);
- unpin_tag(handle);
cache_free_handle(pool, handle);
}
EXPORT_SYMBOL_GPL(zs_free);
@@ -1601,7 +1594,6 @@ static void zs_object_copy(struct size_class *class, unsigned long dst,
static unsigned long find_alloced_obj(struct size_class *class,
struct page *page, int *obj_idx)
{
- unsigned long head;
int offset = 0;
int index = *obj_idx;
unsigned long handle = 0;
@@ -1611,13 +1603,8 @@ static unsigned long find_alloced_obj(struct size_class *class,
offset += class->size * index;
while (offset < PAGE_SIZE) {
- head = obj_to_head(page, addr + offset);
- if (head & OBJ_ALLOCATED_TAG) {
- handle = head & ~OBJ_ALLOCATED_TAG;
- if (trypin_tag(handle))
- break;
- handle = 0;
- }
+ if (obj_allocated(page, addr + offset, &handle))
+ break;
offset += class->size;
index++;
@@ -1663,25 +1650,16 @@ static int migrate_zspage(struct zs_pool *pool, struct size_class *class,
/* Stop if there is no more space */
if (zspage_full(class, get_zspage(d_page))) {
- unpin_tag(handle);
ret = -ENOMEM;
break;
}
used_obj = handle_to_obj(handle);
- free_obj = obj_malloc(class, get_zspage(d_page), handle);
+ free_obj = obj_malloc(pool, get_zspage(d_page), handle);
zs_object_copy(class, free_obj, used_obj);
obj_idx++;
- /*
- * record_obj updates handle's value to free_obj and it will
- * invalidate lock bit(ie, HANDLE_PIN_BIT) of handle, which
- * breaks synchronization using pin_tag(e,g, zs_free) so
- * let's keep the lock bit.
- */
- free_obj |= BIT(HANDLE_PIN_BIT);
record_obj(handle, free_obj);
- unpin_tag(handle);
- obj_free(class, used_obj);
+ obj_free(class->size, used_obj);
}
/* Remember last position in this iteration */
@@ -1706,7 +1684,6 @@ static struct zspage *isolate_zspage(struct size_class *class, bool source)
zspage = list_first_entry_or_null(&class->fullness_list[fg[i]],
struct zspage, list);
if (zspage) {
- VM_BUG_ON(is_zspage_isolated(zspage));
remove_zspage(class, zspage, fg[i]);
return zspage;
}
@@ -1727,8 +1704,6 @@ static enum fullness_group putback_zspage(struct size_class *class,
{
enum fullness_group fullness;
- VM_BUG_ON(is_zspage_isolated(zspage));
-
fullness = get_fullness_group(class, zspage);
insert_zspage(class, zspage, fullness);
set_zspage_mapping(zspage, class->index, fullness);
@@ -1797,6 +1772,11 @@ static void migrate_write_lock(struct zspage *zspage)
write_lock(&zspage->lock);
}
+static void migrate_write_lock_nested(struct zspage *zspage)
+{
+ write_lock_nested(&zspage->lock, SINGLE_DEPTH_NESTING);
+}
+
static void migrate_write_unlock(struct zspage *zspage)
{
write_unlock(&zspage->lock);
@@ -1810,35 +1790,10 @@ static void inc_zspage_isolation(struct zspage *zspage)
static void dec_zspage_isolation(struct zspage *zspage)
{
+ VM_BUG_ON(zspage->isolated == 0);
zspage->isolated--;
}
-static void putback_zspage_deferred(struct zs_pool *pool,
- struct size_class *class,
- struct zspage *zspage)
-{
- enum fullness_group fg;
-
- fg = putback_zspage(class, zspage);
- if (fg == ZS_EMPTY)
- schedule_work(&pool->free_work);
-
-}
-
-static inline void zs_pool_dec_isolated(struct zs_pool *pool)
-{
- VM_BUG_ON(atomic_long_read(&pool->isolated_pages) <= 0);
- atomic_long_dec(&pool->isolated_pages);
- /*
- * Checking pool->destroying must happen after atomic_long_dec()
- * for pool->isolated_pages above. Paired with the smp_mb() in
- * zs_unregister_migration().
- */
- smp_mb__after_atomic();
- if (atomic_long_read(&pool->isolated_pages) == 0 && pool->destroying)
- wake_up_all(&pool->migration_wait);
-}
-
static void replace_sub_page(struct size_class *class, struct zspage *zspage,
struct page *newpage, struct page *oldpage)
{
@@ -1857,19 +1812,14 @@ static void replace_sub_page(struct size_class *class, struct zspage *zspage,
create_page_chain(class, zspage, pages);
set_first_obj_offset(newpage, get_first_obj_offset(oldpage));
- if (unlikely(PageHugeObject(oldpage)))
+ if (unlikely(ZsHugePage(zspage)))
newpage->index = oldpage->index;
__SetPageMovable(newpage, page_mapping(oldpage));
}
static bool zs_page_isolate(struct page *page, isolate_mode_t mode)
{
- struct zs_pool *pool;
- struct size_class *class;
- int class_idx;
- enum fullness_group fullness;
struct zspage *zspage;
- struct address_space *mapping;
/*
* Page is locked so zspage couldn't be destroyed. For detail, look at
@@ -1879,41 +1829,9 @@ static bool zs_page_isolate(struct page *page, isolate_mode_t mode)
VM_BUG_ON_PAGE(PageIsolated(page), page);
zspage = get_zspage(page);
-
- /*
- * Without class lock, fullness could be stale while class_idx is okay
- * because class_idx is constant unless page is freed so we should get
- * fullness again under class lock.
- */
- get_zspage_mapping(zspage, &class_idx, &fullness);
- mapping = page_mapping(page);
- pool = mapping->private_data;
- class = pool->size_class[class_idx];
-
- spin_lock(&class->lock);
- if (get_zspage_inuse(zspage) == 0) {
- spin_unlock(&class->lock);
- return false;
- }
-
- /* zspage is isolated for object migration */
- if (list_empty(&zspage->list) && !is_zspage_isolated(zspage)) {
- spin_unlock(&class->lock);
- return false;
- }
-
- /*
- * If this is first time isolation for the zspage, isolate zspage from
- * size_class to prevent further object allocation from the zspage.
- */
- if (!list_empty(&zspage->list) && !is_zspage_isolated(zspage)) {
- get_zspage_mapping(zspage, &class_idx, &fullness);
- atomic_long_inc(&pool->isolated_pages);
- remove_zspage(class, zspage, fullness);
- }
-
+ migrate_write_lock(zspage);
inc_zspage_isolation(zspage);
- spin_unlock(&class->lock);
+ migrate_write_unlock(zspage);
return true;
}
@@ -1923,16 +1841,13 @@ static int zs_page_migrate(struct address_space *mapping, struct page *newpage,
{
struct zs_pool *pool;
struct size_class *class;
- int class_idx;
- enum fullness_group fullness;
struct zspage *zspage;
struct page *dummy;
void *s_addr, *d_addr, *addr;
- int offset, pos;
- unsigned long handle, head;
+ int offset;
+ unsigned long handle;
unsigned long old_obj, new_obj;
unsigned int obj_idx;
- int ret = -EAGAIN;
/*
* We cannot support the _NO_COPY case here, because copy needs to
@@ -1945,35 +1860,25 @@ static int zs_page_migrate(struct address_space *mapping, struct page *newpage,
VM_BUG_ON_PAGE(!PageMovable(page), page);
VM_BUG_ON_PAGE(!PageIsolated(page), page);
- zspage = get_zspage(page);
-
- /* Concurrent compactor cannot migrate any subpage in zspage */
- migrate_write_lock(zspage);
- get_zspage_mapping(zspage, &class_idx, &fullness);
pool = mapping->private_data;
- class = pool->size_class[class_idx];
- offset = get_first_obj_offset(page);
+ /*
+ * The pool migrate_lock protects the race between zpage migration
+ * and zs_free.
+ */
+ write_lock(&pool->migrate_lock);
+ zspage = get_zspage(page);
+ class = zspage_class(pool, zspage);
+
+ /*
+ * the class lock protects zpage alloc/free in the zspage.
+ */
spin_lock(&class->lock);
- if (!get_zspage_inuse(zspage)) {
- /*
- * Set "offset" to end of the page so that every loops
- * skips unnecessary object scanning.
- */
- offset = PAGE_SIZE;
- }
+ /* the migrate_write_lock protects zpage access via zs_map_object */
+ migrate_write_lock(zspage);
- pos = offset;
+ offset = get_first_obj_offset(page);
s_addr = kmap_atomic(page);
- while (pos < PAGE_SIZE) {
- head = obj_to_head(page, s_addr + pos);
- if (head & OBJ_ALLOCATED_TAG) {
- handle = head & ~OBJ_ALLOCATED_TAG;
- if (!trypin_tag(handle))
- goto unpin_objects;
- }
- pos += class->size;
- }
/*
* Here, any user cannot access all objects in the zspage so let's move.
@@ -1982,42 +1887,30 @@ static int zs_page_migrate(struct address_space *mapping, struct page *newpage,
memcpy(d_addr, s_addr, PAGE_SIZE);
kunmap_atomic(d_addr);
- for (addr = s_addr + offset; addr < s_addr + pos;
+ for (addr = s_addr + offset; addr < s_addr + PAGE_SIZE;
addr += class->size) {
- head = obj_to_head(page, addr);
- if (head & OBJ_ALLOCATED_TAG) {
- handle = head & ~OBJ_ALLOCATED_TAG;
- BUG_ON(!testpin_tag(handle));
+ if (obj_allocated(page, addr, &handle)) {
old_obj = handle_to_obj(handle);
obj_to_location(old_obj, &dummy, &obj_idx);
new_obj = (unsigned long)location_to_obj(newpage,
obj_idx);
- new_obj |= BIT(HANDLE_PIN_BIT);
record_obj(handle, new_obj);
}
}
+ kunmap_atomic(s_addr);
replace_sub_page(class, zspage, newpage, page);
- get_page(newpage);
-
- dec_zspage_isolation(zspage);
-
/*
- * Page migration is done so let's putback isolated zspage to
- * the list if @page is final isolated subpage in the zspage.
+ * Since we complete the data copy and set up new zspage structure,
+ * it's okay to release migration_lock.
*/
- if (!is_zspage_isolated(zspage)) {
- /*
- * We cannot race with zs_destroy_pool() here because we wait
- * for isolation to hit zero before we start destroying.
- * Also, we ensure that everyone can see pool->destroying before
- * we start waiting.
- */
- putback_zspage_deferred(pool, class, zspage);
- zs_pool_dec_isolated(pool);
- }
+ write_unlock(&pool->migrate_lock);
+ spin_unlock(&class->lock);
+ dec_zspage_isolation(zspage);
+ migrate_write_unlock(zspage);
+ get_page(newpage);
if (page_zone(newpage) != page_zone(page)) {
dec_zone_page_state(page, NR_ZSPAGES);
inc_zone_page_state(newpage, NR_ZSPAGES);
@@ -2025,55 +1918,21 @@ static int zs_page_migrate(struct address_space *mapping, struct page *newpage,
reset_page(page);
put_page(page);
- page = newpage;
-
- ret = MIGRATEPAGE_SUCCESS;
-unpin_objects:
- for (addr = s_addr + offset; addr < s_addr + pos;
- addr += class->size) {
- head = obj_to_head(page, addr);
- if (head & OBJ_ALLOCATED_TAG) {
- handle = head & ~OBJ_ALLOCATED_TAG;
- BUG_ON(!testpin_tag(handle));
- unpin_tag(handle);
- }
- }
- kunmap_atomic(s_addr);
- spin_unlock(&class->lock);
- migrate_write_unlock(zspage);
- return ret;
+ return MIGRATEPAGE_SUCCESS;
}
static void zs_page_putback(struct page *page)
{
- struct zs_pool *pool;
- struct size_class *class;
- int class_idx;
- enum fullness_group fg;
- struct address_space *mapping;
struct zspage *zspage;
VM_BUG_ON_PAGE(!PageMovable(page), page);
VM_BUG_ON_PAGE(!PageIsolated(page), page);
zspage = get_zspage(page);
- get_zspage_mapping(zspage, &class_idx, &fg);
- mapping = page_mapping(page);
- pool = mapping->private_data;
- class = pool->size_class[class_idx];
-
- spin_lock(&class->lock);
+ migrate_write_lock(zspage);
dec_zspage_isolation(zspage);
- if (!is_zspage_isolated(zspage)) {
- /*
- * Due to page_lock, we cannot free zspage immediately
- * so let's defer.
- */
- putback_zspage_deferred(pool, class, zspage);
- zs_pool_dec_isolated(pool);
- }
- spin_unlock(&class->lock);
+ migrate_write_unlock(zspage);
}
static const struct address_space_operations zsmalloc_aops = {
@@ -2095,36 +1954,8 @@ static int zs_register_migration(struct zs_pool *pool)
return 0;
}
-static bool pool_isolated_are_drained(struct zs_pool *pool)
-{
- return atomic_long_read(&pool->isolated_pages) == 0;
-}
-
-/* Function for resolving migration */
-static void wait_for_isolated_drain(struct zs_pool *pool)
-{
-
- /*
- * We're in the process of destroying the pool, so there are no
- * active allocations. zs_page_isolate() fails for completely free
- * zspages, so we need only wait for the zs_pool's isolated
- * count to hit zero.
- */
- wait_event(pool->migration_wait,
- pool_isolated_are_drained(pool));
-}
-
static void zs_unregister_migration(struct zs_pool *pool)
{
- pool->destroying = true;
- /*
- * We need a memory barrier here to ensure global visibility of
- * pool->destroying. Thus pool->isolated pages will either be 0 in which
- * case we don't care, or it will be > 0 and pool->destroying will
- * ensure that we wake up once isolation hits 0.
- */
- smp_mb();
- wait_for_isolated_drain(pool); /* This can block */
flush_work(&pool->free_work);
iput(pool->inode);
}
@@ -2154,7 +1985,6 @@ static void async_free_zspage(struct work_struct *work)
spin_unlock(&class->lock);
}
-
list_for_each_entry_safe(zspage, tmp, &free_pages, list) {
list_del(&zspage->list);
lock_zspage(zspage);
@@ -2218,8 +2048,13 @@ static unsigned long __zs_compact(struct zs_pool *pool,
struct zspage *dst_zspage = NULL;
unsigned long pages_freed = 0;
+ /* protect the race between zpage migration and zs_free */
+ write_lock(&pool->migrate_lock);
+ /* protect zpage allocation/free */
spin_lock(&class->lock);
while ((src_zspage = isolate_zspage(class, true))) {
+ /* protect someone accessing the zspage(i.e., zs_map_object) */
+ migrate_write_lock(src_zspage);
if (!zs_can_compact(class))
break;
@@ -2228,6 +2063,8 @@ static unsigned long __zs_compact(struct zs_pool *pool,
cc.s_page = get_first_page(src_zspage);
while ((dst_zspage = isolate_zspage(class, false))) {
+ migrate_write_lock_nested(dst_zspage);
+
cc.d_page = get_first_page(dst_zspage);
/*
* If there is no more space in dst_page, resched
@@ -2237,6 +2074,10 @@ static unsigned long __zs_compact(struct zs_pool *pool,
break;
putback_zspage(class, dst_zspage);
+ migrate_write_unlock(dst_zspage);
+ dst_zspage = NULL;
+ if (rwlock_is_contended(&pool->migrate_lock))
+ break;
}
/* Stop if we couldn't find slot */
@@ -2244,19 +2085,28 @@ static unsigned long __zs_compact(struct zs_pool *pool,
break;
putback_zspage(class, dst_zspage);
+ migrate_write_unlock(dst_zspage);
+
if (putback_zspage(class, src_zspage) == ZS_EMPTY) {
+ migrate_write_unlock(src_zspage);
free_zspage(pool, class, src_zspage);
pages_freed += class->pages_per_zspage;
- }
+ } else
+ migrate_write_unlock(src_zspage);
spin_unlock(&class->lock);
+ write_unlock(&pool->migrate_lock);
cond_resched();
+ write_lock(&pool->migrate_lock);
spin_lock(&class->lock);
}
- if (src_zspage)
+ if (src_zspage) {
putback_zspage(class, src_zspage);
+ migrate_write_unlock(src_zspage);
+ }
spin_unlock(&class->lock);
+ write_unlock(&pool->migrate_lock);
return pages_freed;
}
@@ -2362,15 +2212,12 @@ struct zs_pool *zs_create_pool(const char *name)
return NULL;
init_deferred_free(pool);
+ rwlock_init(&pool->migrate_lock);
pool->name = kstrdup(name, GFP_KERNEL);
if (!pool->name)
goto err;
-#ifdef CONFIG_COMPACTION
- init_waitqueue_head(&pool->migration_wait);
-#endif
-
if (create_cache(pool))
goto err;
diff --git a/mm/zswap.c b/mm/zswap.c
index 7944e3e57e78..cdf6950fcb2e 100644
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -1378,7 +1378,7 @@ static void zswap_frontswap_init(unsigned type)
zswap_trees[type] = tree;
}
-static struct frontswap_ops zswap_frontswap_ops = {
+static const struct frontswap_ops zswap_frontswap_ops = {
.store = zswap_frontswap_store,
.load = zswap_frontswap_load,
.invalidate_page = zswap_frontswap_invalidate_page,
@@ -1475,11 +1475,15 @@ static int __init init_zswap(void)
if (!shrink_wq)
goto fallback_fail;
- frontswap_register_ops(&zswap_frontswap_ops);
+ ret = frontswap_register_ops(&zswap_frontswap_ops);
+ if (ret)
+ goto destroy_wq;
if (zswap_debugfs_init())
pr_warn("debugfs initialization failed\n");
return 0;
+destroy_wq:
+ destroy_workqueue(shrink_wq);
fallback_fail:
if (pool)
zswap_pool_destroy(pool);
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-23 00:27:14 +0000