diff options
| -rw-r--r-- | mm/slub.c | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/mm/slub.c b/mm/slub.c index 8b1b99d399c..4df2c0c337f 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -2332,13 +2332,18 @@ static __always_inline void *slab_alloc_node(struct kmem_cache *s, s = memcg_kmem_get_cache(s, gfpflags); redo: - /* * Must read kmem_cache cpu data via this cpu ptr. Preemption is * enabled. We may switch back and forth between cpus while * reading from one cpu area. That does not matter as long * as we end up on the original cpu again when doing the cmpxchg. + * + * Preemption is disabled for the retrieval of the tid because that + * must occur from the current processor. We cannot allow rescheduling + * on a different processor between the determination of the pointer + * and the retrieval of the tid. */ + preempt_disable(); c = __this_cpu_ptr(s->cpu_slab); /* @@ -2348,7 +2353,7 @@ redo: * linked list in between. */ tid = c->tid; - barrier(); + preempt_enable(); object = c->freelist; page = c->page; @@ -2595,10 +2600,11 @@ redo: * data is retrieved via this pointer. If we are on the same cpu * during the cmpxchg then the free will succedd. */ + preempt_disable(); c = __this_cpu_ptr(s->cpu_slab); tid = c->tid; - barrier(); + preempt_enable(); if (likely(page == c->page)) { set_freepointer(s, object, c->freelist); |