Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755564AbcJNDDg (ORCPT ); Thu, 13 Oct 2016 23:03:36 -0400 Received: from mail-pa0-f65.google.com ([209.85.220.65]:32907 "EHLO mail-pa0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754155AbcJNDDM (ORCPT ); Thu, 13 Oct 2016 23:03:12 -0400 From: js1304@gmail.com X-Google-Original-From: iamjoonsoo.kim@lge.com To: Andrew Morton Cc: Rik van Riel , Johannes Weiner , mgorman@techsingularity.net, Laura Abbott , Minchan Kim , Marek Szyprowski , Michal Nazarewicz , "Aneesh Kumar K.V" , Vlastimil Babka , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Joonsoo Kim Subject: [PATCH v6 1/6] mm/page_alloc: don't reserve ZONE_HIGHMEM for ZONE_MOVABLE request Date: Fri, 14 Oct 2016 12:03:11 +0900 Message-Id: <1476414196-3514-2-git-send-email-iamjoonsoo.kim@lge.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1476414196-3514-1-git-send-email-iamjoonsoo.kim@lge.com> References: <1476414196-3514-1-git-send-email-iamjoonsoo.kim@lge.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2409 Lines: 71 From: Joonsoo Kim Freepage on ZONE_HIGHMEM doesn't work for kernel memory so it's not that important to reserve. When ZONE_MOVABLE is used, this problem would theorectically cause to decrease usable memory for GFP_HIGHUSER_MOVABLE allocation request which is mainly used for page cache and anon page allocation. So, fix it. And, defining sysctl_lowmem_reserve_ratio array by MAX_NR_ZONES - 1 size makes code complex. For example, if there is highmem system, following reserve ratio is activated for *NORMAL ZONE* which would be easyily misleading people. #ifdef CONFIG_HIGHMEM 32 #endif This patch also fix this situation by defining sysctl_lowmem_reserve_ratio array by MAX_NR_ZONES and place "#ifdef" to right place. Reviewed-by: Aneesh Kumar K.V Acked-by: Vlastimil Babka Signed-off-by: Joonsoo Kim --- include/linux/mmzone.h | 2 +- mm/page_alloc.c | 11 ++++++----- 2 files changed, 7 insertions(+), 6 deletions(-) diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 7f2ae99..bd30fc1 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -889,7 +889,7 @@ int min_free_kbytes_sysctl_handler(struct ctl_table *, int, void __user *, size_t *, loff_t *); int watermark_scale_factor_sysctl_handler(struct ctl_table *, int, void __user *, size_t *, loff_t *); -extern int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1]; +extern int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES]; int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *, int, void __user *, size_t *, loff_t *); int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *, int, diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 1790391..92b68cc 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -198,17 +198,18 @@ bool pm_suspended_storage(void) * TBD: should special case ZONE_DMA32 machines here - in those we normally * don't need any ZONE_NORMAL reservation */ -int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = { +int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES] = { #ifdef CONFIG_ZONE_DMA - 256, + [ZONE_DMA] = 256, #endif #ifdef CONFIG_ZONE_DMA32 - 256, + [ZONE_DMA32] = 256, #endif + [ZONE_NORMAL] = 32, #ifdef CONFIG_HIGHMEM - 32, + [ZONE_HIGHMEM] = INT_MAX, #endif - 32, + [ZONE_MOVABLE] = INT_MAX, }; EXPORT_SYMBOL(totalram_pages); -- 1.9.1