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From:   Vlastimil Babka <vbabka@suse.cz>
To:     linux-mm@kvack.org, Christoph Lameter <cl@linux.com>,
        David Rientjes <rientjes@google.com>,
        Pekka Enberg <penberg@kernel.org>,
        Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        linux-kernel@vger.kernel.org, Mike Galbraith <efault@gmx.de>,
        Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
        Thomas Gleixner <tglx@linutronix.de>,
        Mel Gorman <mgorman@techsingularity.net>,
        Vlastimil Babka <vbabka@suse.cz>
Subject: [PATCH v6 29/33] mm: slub: make object_map_lock a raw_spinlock_t
Date:   Sat,  4 Sep 2021 12:49:59 +0200
Message-Id: <20210904105003.11688-30-vbabka@suse.cz>
In-Reply-To: <20210904105003.11688-1-vbabka@suse.cz>
References: <20210904105003.11688-1-vbabka@suse.cz>
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From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

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 <bigeasy@linutronix.de>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
---
 mm/slub.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/mm/slub.c b/mm/slub.c
index b7f8b9d34e46..76e56ce55d21 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -452,7 +452,7 @@ 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)
@@ -497,7 +497,7 @@ 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);
 
@@ -507,7 +507,7 @@ 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)
-- 
2.33.0