Merge branch 'slab/urgent' into slab/for-linus

[~andy/linux] / mm / slub.c

diff --git a/mm/slub.c b/mm/slub.c
index 8284a206f48d2da3a712adb726ec4319c91c632f..19436f53876079b6de95e13270d1ef5b22a169c6 100644 (file)
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -570,7 +570,7 @@ static void slab_bug(struct kmem_cache *s, char *fmt, ...)
        va_end(args);
        printk(KERN_ERR "========================================"
                        "=====================================\n");
-       printk(KERN_ERR "BUG %s: %s\n", s->name, buf);
+       printk(KERN_ERR "BUG %s (%s): %s\n", s->name, print_tainted(), buf);
        printk(KERN_ERR "----------------------------------------"
                        "-------------------------------------\n\n");
 }
@@ -2126,6 +2126,37 @@ static inline void *new_slab_objects(struct kmem_cache *s, gfp_t flags,
        return object;
 }
 
+/*
+ * Check the page->freelist of a page and either transfer the freelist to the per cpu freelist
+ * or deactivate the page.
+ *
+ * The page is still frozen if the return value is not NULL.
+ *
+ * If this function returns NULL then the page has been unfrozen.
+ */
+static inline void *get_freelist(struct kmem_cache *s, struct page *page)
+{
+       struct page new;
+       unsigned long counters;
+       void *freelist;
+
+       do {
+               freelist = page->freelist;
+               counters = page->counters;
+               new.counters = counters;
+               VM_BUG_ON(!new.frozen);
+
+               new.inuse = page->objects;
+               new.frozen = freelist != NULL;
+
+       } while (!cmpxchg_double_slab(s, page,
+               freelist, counters,
+               NULL, new.counters,
+               "get_freelist"));
+
+       return freelist;
+}
+
 /*
  * Slow path. The lockless freelist is empty or we need to perform
  * debugging duties.
@@ -2147,8 +2178,6 @@ static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
 {
        void **object;
        unsigned long flags;
-       struct page new;
-       unsigned long counters;
 
        local_irq_save(flags);
 #ifdef CONFIG_PREEMPT
@@ -2169,31 +2198,14 @@ redo:
                goto new_slab;
        }
 
-       stat(s, ALLOC_SLOWPATH);
-
-       do {
-               object = c->page->freelist;
-               counters = c->page->counters;
-               new.counters = counters;
-               VM_BUG_ON(!new.frozen);
-
-               /*
-                * If there is no object left then we use this loop to
-                * deactivate the slab which is simple since no objects
-                * are left in the slab and therefore we do not need to
-                * put the page back onto the partial list.
-                *
-                * If there are objects left then we retrieve them
-                * and use them to refill the per cpu queue.
-                */
+       /* must check again c->freelist in case of cpu migration or IRQ */
+       object = c->freelist;
+       if (object)
+               goto load_freelist;
 
-               new.inuse = c->page->objects;
-               new.frozen = object != NULL;
+       stat(s, ALLOC_SLOWPATH);
 
-       } while (!__cmpxchg_double_slab(s, c->page,
-                       object, counters,
-                       NULL, new.counters,
-                       "__slab_alloc"));
+       object = get_freelist(s, c->page);
 
        if (!object) {
                c->page = NULL;
@@ -4639,6 +4651,8 @@ static ssize_t cpu_partial_store(struct kmem_cache *s, const char *buf,
        err = strict_strtoul(buf, 10, &objects);
        if (err)
                return err;
+       if (objects && kmem_cache_debug(s))
+               return -EINVAL;
 
        s->cpu_partial = objects;
        flush_all(s);