From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f42.google.com (mail-pa0-f42.google.com [209.85.220.42]) by kanga.kvack.org (Postfix) with ESMTP id BF37E6B003D for ; Tue, 24 Jun 2014 03:39:43 -0400 (EDT) Received: by mail-pa0-f42.google.com with SMTP id lj1so6942298pab.1 for ; Tue, 24 Jun 2014 00:39:43 -0700 (PDT) Received: from lgeamrelo04.lge.com (lgeamrelo04.lge.com. [156.147.1.127]) by mx.google.com with ESMTP id ty7si25103564pab.10.2014.06.24.00.39.39 for ; Tue, 24 Jun 2014 00:39:42 -0700 (PDT) From: 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> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: Christoph Lameter , Pekka Enberg , David Rientjes , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Vladimir Davydov , Joonsoo Kim 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, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org