Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761692AbZFKIoc (ORCPT ); Thu, 11 Jun 2009 04:44:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1760828AbZFKIoY (ORCPT ); Thu, 11 Jun 2009 04:44:24 -0400 Received: from courier.cs.helsinki.fi ([128.214.9.1]:44894 "EHLO mail.cs.helsinki.fi" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760635AbZFKIoX (ORCPT ); Thu, 11 Jun 2009 04:44:23 -0400 Date: Thu, 11 Jun 2009 11:44:25 +0300 (EEST) From: Pekka J Enberg To: linux-kernel@vger.kernel.org cc: cl@linux-foundation.org, mel@csn.ul.ie, Larry.Finger@lwfinger.net Subject: [PATCH 2/2] SLUB: Disable debugging if it increases the minimum page order Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1774 Lines: 56 From: Pekka Enberg As CONFIG_SLUB_DEBUG is almost always enabled, we need to disable debugging on per-cache basis if the added debug metadata increases minimum page order. This is a problem for large caches such as kmalloc-4096 as seen in the following bugzilla report: http://bugzilla.kernel.org/show_bug.cgi?id=13319 Cc: Christoph Lameter Cc: Larry Finger Cc: Mel Gorman Signed-off-by: Pekka Enberg --- mm/slub.c | 13 +++++++++++++ 1 files changed, 13 insertions(+), 0 deletions(-) diff --git a/mm/slub.c b/mm/slub.c index 2bbacfc..45080d3 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -2385,6 +2385,16 @@ static int calculate_sizes(struct kmem_cache *s, int forced_order) } +#define MAX_DEBUG_SIZE (3 * sizeof(void *) + 2 * sizeof(struct track)) + +static bool must_disable_debug(size_t size) +{ + /* + * Disable debugging if it increases the minimum page order. + */ + return get_order(size + MAX_DEBUG_SIZE) > get_order(size); +} + static int kmem_cache_open(struct kmem_cache *s, gfp_t gfpflags, const char *name, size_t size, size_t align, unsigned long flags, @@ -2397,6 +2407,9 @@ static int kmem_cache_open(struct kmem_cache *s, gfp_t gfpflags, s->align = align; s->flags = kmem_cache_flags(size, flags, name, ctor); + if (must_disable_debug(size)) + s->flags &= ~(SLAB_POISON|SLAB_RED_ZONE|SLAB_STORE_USER); + if (!calculate_sizes(s, -1)) goto error; -- 1.6.0.4 -- 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/