diff mbox series

[RESEND,1/3] mm/zsmalloc: fix migrate_write_lock() when !CONFIG_COMPACTION

Message ID 20240219-b4-szmalloc-migrate-v1-1-fc21039bed7b@linux.dev (mailing list archive)
State New
Headers show
Series mm/zsmalloc: fix and optimize objects/page migration | expand

Commit Message

Chengming Zhou Feb. 20, 2024, 11:36 a.m. UTC 
From: Chengming Zhou <zhouchengming@bytedance.com>

migrate_write_lock() is a empty function when !CONFIG_COMPACTION, in
which case zs_compact() can be triggered from shrinker reclaim context.
(Maybe it's better to rename it to zs_shrink()?)

And zspage map object users rely on this migrate_read_lock() so object
won't be migrated elsewhere.

Fix it by always implementing the migrate_write_lock() related functions.

Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
---
 mm/zsmalloc.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

Comments

Sergey Senozhatsky Feb. 23, 2024, 5:49 a.m. UTC | #1 
On (24/02/20 11:36), Chengming Zhou wrote:
> From: Chengming Zhou <zhouchengming@bytedance.com>
> 
> migrate_write_lock() is a empty function when !CONFIG_COMPACTION, in
> which case zs_compact() can be triggered from shrinker reclaim context.
> (Maybe it's better to rename it to zs_shrink()?)
> 
> And zspage map object users rely on this migrate_read_lock() so object
> won't be migrated elsewhere.
> 
> Fix it by always implementing the migrate_write_lock() related functions.
> 
> Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>

Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
diff mbox series

Patch

diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index c937635e0ad1..64d5533fa5d8 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -278,18 +278,15 @@  static bool ZsHugePage(struct zspage *zspage)
 static void migrate_lock_init(struct zspage *zspage);
 static void migrate_read_lock(struct zspage *zspage);
 static void migrate_read_unlock(struct zspage *zspage);
-
-#ifdef CONFIG_COMPACTION
 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);
+
+#ifdef CONFIG_COMPACTION
 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);
 #else
-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) {}
@@ -1725,7 +1722,6 @@  static void migrate_read_unlock(struct zspage *zspage) __releases(&zspage->lock)
 	read_unlock(&zspage->lock);
 }
 
-#ifdef CONFIG_COMPACTION
 static void migrate_write_lock(struct zspage *zspage)
 {
 	write_lock(&zspage->lock);
@@ -1741,6 +1737,7 @@  static void migrate_write_unlock(struct zspage *zspage)
 	write_unlock(&zspage->lock);
 }
 
+#ifdef CONFIG_COMPACTION
 /* Number of isolated subpage for *page migration* in this zspage */
 static void inc_zspage_isolation(struct zspage *zspage)
 {