[RFC,v2,30/34] mm: slub: Make object_map_lock a raw_spinlock_t

Commit Message

Vlastimil Babka June 9, 2021, 11:38 a.m. UTC

From: Sebastian Andrzej Siewior <[e-mail]>

The variable object_map is protected by object_map_lock. The lock is always
acquired in debug code and within already atomic context

Make object_map_lock a raw_spinlock_t.

Signed-off-by: Sebastian Andrzej Siewior <[e-mail]>
Signed-off-by: Vlastimil Babka <[e-mail]>
---
 mm/slub.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

Patch

diff --git a/mm/slub.c b/mm/slub.c
index 6e747e0d7dcd..cfd5a7660375 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -432,7 +432,7 @@  static inline bool cmpxchg_double_slab(struct kmem_cache *s, struct page *page,
 
 #ifdef CONFIG_SLUB_DEBUG
 static unsigned long object_map[BITS_TO_LONGS(MAX_OBJS_PER_PAGE)];
-static DEFINE_SPINLOCK(object_map_lock);
+static DEFINE_RAW_SPINLOCK(object_map_lock);
 
 static void __fill_map(unsigned long *obj_map, struct kmem_cache *s,
 		       struct page *page)
@@ -457,7 +457,7 @@  static unsigned long *get_map(struct kmem_cache *s, struct page *page)
 {
 	VM_BUG_ON(!irqs_disabled());
 
-	spin_lock(&object_map_lock);
+	raw_spin_lock(&object_map_lock);
 
 	__fill_map(object_map, s, page);
 
@@ -467,7 +467,7 @@  static unsigned long *get_map(struct kmem_cache *s, struct page *page)
 static void put_map(unsigned long *map) __releases(&object_map_lock)
 {
 	VM_BUG_ON(map != object_map);
-	spin_unlock(&object_map_lock);
+	raw_spin_unlock(&object_map_lock);
 }
 
 static inline unsigned int size_from_object(struct kmem_cache *s)