From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755626AbcANF0n (ORCPT ); Thu, 14 Jan 2016 00:26:43 -0500 Received: from mail-pf0-f196.google.com ([209.85.192.196]:32892 "EHLO mail-pf0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755236AbcANFZG (ORCPT ); Thu, 14 Jan 2016 00:25:06 -0500 From: Joonsoo Kim X-Google-Original-From: Joonsoo Kim To: Andrew Morton Cc: Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Jesper Dangaard Brouer , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH 12/16] mm/slab: do not change cache size if debug pagealloc isn't possible Date: Thu, 14 Jan 2016 14:24:25 +0900 Message-Id: <1452749069-15334-13-git-send-email-iamjoonsoo.kim@lge.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1452749069-15334-1-git-send-email-iamjoonsoo.kim@lge.com> References: <1452749069-15334-1-git-send-email-iamjoonsoo.kim@lge.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We can fail to setup off slab in some conditions. Even in this case, debug pagealloc increases cache size to PAGE_SIZE in advance and it is waste because debug pagealloc cannot work for it when it isn't the off slab. To improve this situation, this patch checks first that this cache with increased size is suitable for off slab. It actually increases cache size when it is suitable for off-slab, so possible waste is removed. Signed-off-by: Joonsoo Kim --- mm/slab.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/mm/slab.c b/mm/slab.c index 7a253a9..b0f6eda 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -2207,10 +2207,17 @@ __kmem_cache_create (struct kmem_cache *cachep, unsigned long flags) */ if (debug_pagealloc_enabled() && (flags & SLAB_POISON) && !slab_early_init && size >= kmalloc_size(INDEX_NODE) && - size >= 256 && cachep->object_size > cache_line_size() && - size < PAGE_SIZE) { - cachep->obj_offset += PAGE_SIZE - size; - size = PAGE_SIZE; + size >= 256 && cachep->object_size > cache_line_size()) { + if (size < PAGE_SIZE || size % PAGE_SIZE == 0) { + size_t tmp_size = ALIGN(size, PAGE_SIZE); + + if (set_off_slab_cache(cachep, tmp_size, flags)) { + flags |= CFLGS_OFF_SLAB; + cachep->obj_offset += tmp_size - size; + size = tmp_size; + goto done; + } + } } #endif -- 1.9.1