diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index 648306245d5131110077cc27a174de2928773808..c150cea15a6c11c211faacd6b3d606ba4a04f8c8 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -254,10 +254,6 @@ 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
};
@@ -454,11 +450,6 @@ MODULE_ALIAS("zpool-zsmalloc");
/* 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 __maybe_unused int is_first_page(struct page *page)
{
return PagePrivate(page);
@@ -744,7 +735,6 @@ 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);
class_stat_dec(class, fullness, 1);
@@ -770,13 +760,9 @@ 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;
}
@@ -1511,7 +1497,6 @@ void zs_free(struct zs_pool *pool, unsigned long handle)
unsigned long obj;
struct size_class *class;
enum fullness_group fullness;
- bool isolated;
if (unlikely(!handle))
return;
@@ -1533,11 +1518,9 @@ void zs_free(struct zs_pool *pool, unsigned long handle)
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);
@@ -1718,7 +1701,6 @@ 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;
}
@@ -1739,8 +1721,6 @@ 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);
@@ -1822,35 +1802,10 @@ 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)
{
@@ -1876,10 +1831,7 @@ static void replace_sub_page(struct size_class *class, struct zspage *zspage,
static bool zs_page_isolate(struct page *page, isolate_mode_t mode)
{
- struct zs_pool *pool;
- struct size_class *class;
struct zspage *zspage;
- struct address_space *mapping;
/*
* Page is locked so zspage couldn't be destroyed. For detail, look at
@@ -1889,39 +1841,9 @@ static bool zs_page_isolate(struct page *page, isolate_mode_t mode)
VM_BUG_ON_PAGE(PageIsolated(page), page);
zspage = get_zspage(page);
-
- mapping = page_mapping(page);
- pool = mapping->private_data;
-
- class = zspage_class(pool, zspage);
-
- 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)) {
- enum fullness_group fullness;
- unsigned int class_idx;
-
- 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;
}
@@ -2004,21 +1926,6 @@ static int zs_page_migrate(struct address_space *mapping, struct 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.
- */
- 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);
- }
-
if (page_zone(newpage) != page_zone(page)) {
dec_zone_page_state(page, NR_ZSPAGES);
inc_zone_page_state(newpage, NR_ZSPAGES);
@@ -2046,30 +1953,15 @@ static int zs_page_migrate(struct address_space *mapping, struct page *newpage,
static void zs_page_putback(struct page *page)
{
- struct zs_pool *pool;
- struct size_class *class;
- 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);
- mapping = page_mapping(page);
- pool = mapping->private_data;
- class = zspage_class(pool, zspage);
-
- 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 = {
@@ -2091,36 +1983,8 @@ 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);
}
@@ -2150,7 +2014,6 @@ 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);
@@ -2363,10 +2226,6 @@ struct zs_pool *zs_create_pool(const char *name)
if (!pool->name)
goto err;
-#ifdef CONFIG_COMPACTION
- init_waitqueue_head(&pool->migration_wait);
-#endif
-
if (create_cache(pool))
goto err;