Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752131AbaFXHjl (ORCPT ); Tue, 24 Jun 2014 03:39:41 -0400 Received: from lgeamrelo04.lge.com ([156.147.1.127]:62566 "EHLO lgeamrelo04.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751242AbaFXHjj (ORCPT ); Tue, 24 Jun 2014 03:39:39 -0400 X-Original-SENDERIP: 10.177.220.145 X-Original-MAILFROM: iamjoonsoo.kim@lge.com From: Joonsoo Kim To: Andrew Morton Cc: Christoph Lameter , Pekka Enberg , David Rientjes , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Vladimir Davydov , Joonsoo Kim Subject: [PATCH] slub: fix off by one in number of slab tests Date: Tue, 24 Jun 2014 16:44:01 +0900 Message-Id: <1403595842-28270-1-git-send-email-iamjoonsoo.kim@lge.com> X-Mailer: git-send-email 1.7.9.5 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org min_partial means minimum number of slab cached in node partial list. So, if nr_partial is less than it, we keep newly empty slab on node partial list rather than freeing it. But if nr_partial is equal or greater than it, it means that we have enough partial slabs so should free newly empty slab. Current implementation missed the equal case so if we set min_partial is 0, then, at least one slab could be cached. This is critical problem to kmemcg destroying logic because it doesn't works properly if some slabs is cached. This patch fixes this problem. Signed-off-by: Joonsoo Kim diff --git a/mm/slub.c b/mm/slub.c index c567927..67da14d 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -1851,7 +1851,7 @@ redo: new.frozen = 0; - if (!new.inuse && n->nr_partial > s->min_partial) + if (!new.inuse && n->nr_partial >= s->min_partial) m = M_FREE; else if (new.freelist) { m = M_PARTIAL; @@ -1962,7 +1962,7 @@ static void unfreeze_partials(struct kmem_cache *s, new.freelist, new.counters, "unfreezing slab")); - if (unlikely(!new.inuse && n->nr_partial > s->min_partial)) { + if (unlikely(!new.inuse && n->nr_partial >= s->min_partial)) { page->next = discard_page; discard_page = page; } else { @@ -2595,7 +2595,7 @@ static void __slab_free(struct kmem_cache *s, struct page *page, return; } - if (unlikely(!new.inuse && n->nr_partial > s->min_partial)) + if (unlikely(!new.inuse && n->nr_partial >= s->min_partial)) goto slab_empty; /* -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/