Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750828Ab3IFF5t (ORCPT ); Fri, 6 Sep 2013 01:57:49 -0400 Received: from LGEMRELSE1Q.lge.com ([156.147.1.111]:57945 "EHLO LGEMRELSE1Q.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750766Ab3IFF5q (ORCPT ); Fri, 6 Sep 2013 01:57:46 -0400 X-AuditID: 9c93016f-b7cf0ae00000518f-58-52296ed93011 From: Joonsoo Kim To: Pekka Enberg Cc: Christoph Lameter , Andrew Morton , Joonsoo Kim , David Rientjes , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Joonsoo Kim Subject: [REPOST PATCH 1/4] slab: factor out calculate nr objects in cache_estimate Date: Fri, 6 Sep 2013 14:57:44 +0900 Message-Id: <1378447067-19832-2-git-send-email-iamjoonsoo.kim@lge.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1378447067-19832-1-git-send-email-iamjoonsoo.kim@lge.com> References: <1378447067-19832-1-git-send-email-iamjoonsoo.kim@lge.com> X-Brightmail-Tracker: AAAAAA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2779 Lines: 86 This logic is not simple to understand so that making separate function helping readability. Additionally, we can use this change in the following patch which implement for freelist to have another sized index in according to nr objects. Signed-off-by: Joonsoo Kim diff --git a/mm/slab.c b/mm/slab.c index f3868fe..9d4bad5 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -565,9 +565,31 @@ static inline struct array_cache *cpu_cache_get(struct kmem_cache *cachep) return cachep->array[smp_processor_id()]; } -static size_t slab_mgmt_size(size_t nr_objs, size_t align) +static int calculate_nr_objs(size_t slab_size, size_t buffer_size, + size_t idx_size, size_t align) { - return ALIGN(nr_objs * sizeof(unsigned int), align); + int nr_objs; + size_t freelist_size; + + /* + * Ignore padding for the initial guess. The padding + * is at most @align-1 bytes, and @buffer_size is at + * least @align. In the worst case, this result will + * be one greater than the number of objects that fit + * into the memory allocation when taking the padding + * into account. + */ + nr_objs = slab_size / (buffer_size + idx_size); + + /* + * This calculated number will be either the right + * amount, or one greater than what we want. + */ + freelist_size = slab_size - nr_objs * buffer_size; + if (freelist_size < ALIGN(nr_objs * idx_size, align)) + nr_objs--; + + return nr_objs; } /* @@ -600,28 +622,12 @@ static void cache_estimate(unsigned long gfporder, size_t buffer_size, nr_objs = slab_size / buffer_size; } else { - /* - * Ignore padding for the initial guess. The padding - * is at most @align-1 bytes, and @buffer_size is at - * least @align. In the worst case, this result will - * be one greater than the number of objects that fit - * into the memory allocation when taking the padding - * into account. - */ - nr_objs = (slab_size) / (buffer_size + sizeof(unsigned int)); - - /* - * This calculated number will be either the right - * amount, or one greater than what we want. - */ - if (slab_mgmt_size(nr_objs, align) + nr_objs*buffer_size - > slab_size) - nr_objs--; - - mgmt_size = slab_mgmt_size(nr_objs, align); + nr_objs = calculate_nr_objs(slab_size, buffer_size, + sizeof(unsigned int), align); + mgmt_size = ALIGN(nr_objs * sizeof(unsigned int), align); } *num = nr_objs; - *left_over = slab_size - nr_objs*buffer_size - mgmt_size; + *left_over = slab_size - (nr_objs * buffer_size) - mgmt_size; } #if DEBUG -- 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/