mm, slub: detach whole partial list at once in unfreeze_partials()

Instead of iterating through the live percpu partial list, detach it from the
kmem_cache_cpu at once. This is simpler and will allow further optimization.

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>

diff --git a/mm/slub.c b/mm/slub.c
index 0a1e048..b31e00e 100644 (file)
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -2358,16 +2358,20 @@ static void unfreeze_partials(struct kmem_cache *s,
 {
 #ifdef CONFIG_SLUB_CPU_PARTIAL
        struct kmem_cache_node *n = NULL, *n2 = NULL;
-       struct page *page, *discard_page = NULL;
+       struct page *page, *partial_page, *discard_page = NULL;
        unsigned long flags;
 
        local_irq_save(flags);
 
-       while ((page = slub_percpu_partial(c))) {
+       partial_page = slub_percpu_partial(c);
+       c->partial = NULL;
+
+       while (partial_page) {
                struct page new;
                struct page old;
 
-               slub_set_percpu_partial(c, page);
+               page = partial_page;
+               partial_page = page->next;
 
                n2 = get_node(s, page_to_nid(page));
                if (n != n2) {