Messages in this thread | | | Date | Wed, 2 Dec 2015 10:06:13 -0600 (CST) | From | Christoph Lameter <> | Subject | Re: [PATCH 3/3] mm/slab: use list_{empty_careful,last_entry} in drain_freelist |
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On Wed, 2 Dec 2015, Geliang Tang wrote:
> diff --git a/mm/slab.c b/mm/slab.c > index 5d5aa3b..1a7d91c 100644 > --- a/mm/slab.c > +++ b/mm/slab.c > @@ -2362,21 +2362,14 @@ static void drain_cpu_caches(struct kmem_cache *cachep) > static int drain_freelist(struct kmem_cache *cache, > struct kmem_cache_node *n, int tofree) > { > - struct list_head *p; > int nr_freed; > struct page *page; > > nr_freed = 0; > - while (nr_freed < tofree && !list_empty(&n->slabs_free)) { > + while (nr_freed < tofree && !list_empty_careful(&n->slabs_free)) { > > spin_lock_irq(&n->list_lock); > - p = n->slabs_free.prev; > - if (p == &n->slabs_free) { > - spin_unlock_irq(&n->list_lock); > - goto out; > - } > - > - page = list_entry(p, struct page, lru); > + page = list_last_entry(&n->slabs_free, struct page, lru);
This is safe? Process could be rescheduled and lots of things could happen before disabling irqs.
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