Commit 0d6fa44e authored by Sergey Senozhatsky's avatar Sergey Senozhatsky Committed by Andrew Morton
Browse files

zsmalloc: rename pool lock 

The old name comes from the times when the pool did not have compaction
(defragmentation).  Rename it to ->lock because these days it synchronizes
not only migration.

Link: https://lkml.kernel.org/r/20250303022425.285971-13-senozhatsky@chromium.org


Signed-off-by: default avatarSergey Senozhatsky <senozhatsky@chromium.org>
Reviewed-by: default avatarYosry Ahmed <yosry.ahmed@linux.dev>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Kairui Song <ryncsn@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 7e1b0212

mm/zsmalloc.c

+19 −19
Original line number Diff line number Diff line
@@ -18,7 +18,7 @@ 
/*

 * lock ordering:

 *	page_lock

 *	pool->migrate_lock

 *	pool->lock

 *	class->lock

 *	zspage->lock

 */
@@ -223,8 +223,8 @@ struct zs_pool { 
#ifdef CONFIG_COMPACTION

	struct work_struct free_work;

#endif

	/* protect page/zspage migration */

	rwlock_t migrate_lock;

	/* protect zspage migration/compaction */

	rwlock_t lock;

	atomic_t compaction_in_progress;

};
@@ -1206,7 +1206,7 @@ void *zs_map_object(struct zs_pool *pool, unsigned long handle, 
	BUG_ON(in_interrupt());



	/* It guarantees it can get zspage from handle safely */

	read_lock(&pool->migrate_lock);

	read_lock(&pool->lock);

	obj = handle_to_obj(handle);

	obj_to_location(obj, &zpdesc, &obj_idx);

	zspage = get_zspage(zpdesc);
@@ -1218,7 +1218,7 @@ void *zs_map_object(struct zs_pool *pool, unsigned long handle, 
	 * which is smaller granularity.

	 */

	migrate_read_lock(zspage);

	read_unlock(&pool->migrate_lock);

	read_unlock(&pool->lock);



	class = zspage_class(pool, zspage);

	off = offset_in_page(class->size * obj_idx);
@@ -1450,16 +1450,16 @@ void zs_free(struct zs_pool *pool, unsigned long handle) 
		return;



	/*

	 * The pool->migrate_lock protects the race with zpage's migration

	 * The pool->lock protects the race with zpage's migration

	 * so it's safe to get the page from handle.

	 */

	read_lock(&pool->migrate_lock);

	read_lock(&pool->lock);

	obj = handle_to_obj(handle);

	obj_to_zpdesc(obj, &f_zpdesc);

	zspage = get_zspage(f_zpdesc);

	class = zspage_class(pool, zspage);

	spin_lock(&class->lock);

	read_unlock(&pool->migrate_lock);

	read_unlock(&pool->lock);



	class_stat_sub(class, ZS_OBJS_INUSE, 1);

	obj_free(class->size, obj);
@@ -1796,7 +1796,7 @@ static int zs_page_migrate(struct page *newpage, struct page *page, 
	 * The pool migrate_lock protects the race between zpage migration

	 * and zs_free.

	 */

	write_lock(&pool->migrate_lock);

	write_lock(&pool->lock);

	class = zspage_class(pool, zspage);



	/*
@@ -1833,7 +1833,7 @@ static int zs_page_migrate(struct page *newpage, struct page *page, 
	 * Since we complete the data copy and set up new zspage structure,

	 * it's okay to release migration_lock.

	 */

	write_unlock(&pool->migrate_lock);

	write_unlock(&pool->lock);

	spin_unlock(&class->lock);

	migrate_write_unlock(zspage);
@@ -1956,7 +1956,7 @@ static unsigned long __zs_compact(struct zs_pool *pool, 
	 * protect the race between zpage migration and zs_free

	 * as well as zpage allocation/free

	 */

	write_lock(&pool->migrate_lock);

	write_lock(&pool->lock);

	spin_lock(&class->lock);

	while (zs_can_compact(class)) {

		int fg;
@@ -1983,14 +1983,14 @@ static unsigned long __zs_compact(struct zs_pool *pool, 
		src_zspage = NULL;



		if (get_fullness_group(class, dst_zspage) == ZS_INUSE_RATIO_100

		    || rwlock_is_contended(&pool->migrate_lock)) {

		    || rwlock_is_contended(&pool->lock)) {

			putback_zspage(class, dst_zspage);

			dst_zspage = NULL;



			spin_unlock(&class->lock);

			write_unlock(&pool->migrate_lock);

			write_unlock(&pool->lock);

			cond_resched();

			write_lock(&pool->migrate_lock);

			write_lock(&pool->lock);

			spin_lock(&class->lock);

		}

	}
@@ -2002,7 +2002,7 @@ static unsigned long __zs_compact(struct zs_pool *pool, 
		putback_zspage(class, dst_zspage);



	spin_unlock(&class->lock);

	write_unlock(&pool->migrate_lock);

	write_unlock(&pool->lock);



	return pages_freed;

}
@@ -2014,10 +2014,10 @@ unsigned long zs_compact(struct zs_pool *pool) 
	unsigned long pages_freed = 0;



	/*

	 * Pool compaction is performed under pool->migrate_lock so it is basically

	 * Pool compaction is performed under pool->lock so it is basically

	 * single-threaded. Having more than one thread in __zs_compact()

	 * will increase pool->migrate_lock contention, which will impact other

	 * zsmalloc operations that need pool->migrate_lock.

	 * will increase pool->lock contention, which will impact other

	 * zsmalloc operations that need pool->lock.

	 */

	if (atomic_xchg(&pool->compaction_in_progress, 1))

		return 0;
@@ -2139,7 +2139,7 @@ struct zs_pool *zs_create_pool(const char *name) 
		return NULL;



	init_deferred_free(pool);

	rwlock_init(&pool->migrate_lock);

	rwlock_init(&pool->lock);

	atomic_set(&pool->compaction_in_progress, 0);



	pool->name = kstrdup(name, GFP_KERNEL);