slub: Use correct cpu_slab on dead cpu

Pass a kmem_cache_cpu pointer into unfreeze partials so that a different
kmem_cache_cpu structure than the local one can be specified.

Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>

diff --git a/mm/slub.c b/mm/slub.c
index b2ada3db42251730198f9597c489307e3a78b768..33576b0cfc41a9455cb6804855061ef223c2eb6b 100644 (file)
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1869,12 +1869,14 @@ redo:
 /*
  * Unfreeze all the cpu partial slabs.
  *
- * This function must be called with interrupt disabled.
+ * This function must be called with interrupts disabled
+ * for the cpu using c (or some other guarantee must be there
+ * to guarantee no concurrent accesses).
  */
-static void unfreeze_partials(struct kmem_cache *s)
+static void unfreeze_partials(struct kmem_cache *s,
+               struct kmem_cache_cpu *c)
 {
        struct kmem_cache_node *n = NULL, *n2 = NULL;
-       struct kmem_cache_cpu *c = this_cpu_ptr(s->cpu_slab);
        struct page *page, *discard_page = NULL;
 
        while ((page = c->partial)) {
@@ -1960,7 +1962,7 @@ static int put_cpu_partial(struct kmem_cache *s, struct page *page, int drain)
                                 * set to the per node partial list.
                                 */
                                local_irq_save(flags);
-                               unfreeze_partials(s);
+                               unfreeze_partials(s, this_cpu_ptr(s->cpu_slab));
                                local_irq_restore(flags);
                                oldpage = NULL;
                                pobjects = 0;
@@ -2003,7 +2005,7 @@ static inline void __flush_cpu_slab(struct kmem_cache *s, int cpu)
                if (c->page)
                        flush_slab(s, c);
 
-               unfreeze_partials(s);
+               unfreeze_partials(s, c);
        }
 }