The patch titled
Subject: zsmalloc: rename pool lock
has been added to the -mm mm-unstable branch. Its filename is
zsmalloc-rename-pool-lock.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/zsmalloc-rename-pool-lock.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
Subject: zsmalloc: rename pool lock
Date: Sat, 22 Feb 2025 07:25:41 +0900
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/20250221222958.2225035-11-senozhatsky@xxxxxxxxxxxx
Signed-off-by: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
Reviewed-by: Yosry Ahmed <yosry.ahmed@xxxxxxxxx>
Cc: Hillf Danton <hdanton@xxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/zsmalloc.c | 38 +++++++++++++++++++-------------------
1 file changed, 19 insertions(+), 19 deletions(-)
--- a/mm/zsmalloc.c~zsmalloc-rename-pool-lock
+++ a/mm/zsmalloc.c
@@ -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
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
* 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, unsig
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 *
* 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 *
* 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
* 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
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
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
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 cha
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);
_
Patches currently in -mm which might be from senozhatsky@xxxxxxxxxxxx are
zram-sleepable-entry-locking.patch
zram-permit-preemption-with-active-compression-stream.patch
zram-remove-unused-crypto-include.patch
zram-remove-max_comp_streams-device-attr.patch
zram-remove-second-stage-of-handle-allocation.patch
zram-remove-writestall-zram_stats-member.patch
zram-limit-max-recompress-prio-to-num_active_comps.patch
zram-filter-out-recomp-targets-based-on-priority.patch
zram-rework-recompression-loop.patch
zsmalloc-rename-pool-lock.patch
zsmalloc-make-zspage-lock-preemptible.patch
zsmalloc-introduce-new-object-mapping-api.patch
zram-switch-to-new-zsmalloc-object-mapping-api.patch
zram-permit-reclaim-in-zstd-custom-allocator.patch
zram-do-not-leak-page-on-recompress_store-error-path.patch
zram-do-not-leak-page-on-writeback_store-error-path.patch
zram-add-might_sleep-to-zcomp-api.patch
zsmalloc-zram-there-be-preemption.patch
