From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933125AbcIVFWD (ORCPT ); Thu, 22 Sep 2016 01:22:03 -0400 Received: from LGEAMRELO11.lge.com ([156.147.23.51]:35086 "EHLO lgeamrelo11.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751562AbcIVFWC (ORCPT ); Thu, 22 Sep 2016 01:22:02 -0400 X-Original-SENDERIP: 156.147.1.151 X-Original-MAILFROM: iamjoonsoo.kim@lge.com X-Original-SENDERIP: 10.177.222.138 X-Original-MAILFROM: iamjoonsoo.kim@lge.com Date: Thu, 22 Sep 2016 14:30:03 +0900 From: Joonsoo Kim To: "Aneesh Kumar K.V" Cc: Andrew Morton , Rik van Riel , Johannes Weiner , mgorman@techsingularity.net, Laura Abbott , Minchan Kim , Marek Szyprowski , Michal Nazarewicz , Vlastimil Babka , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v5 1/6] mm/page_alloc: don't reserve ZONE_HIGHMEM for ZONE_MOVABLE request Message-ID: <20160922053003.GA27958@js1304-P5Q-DELUXE> References: <1472447255-10584-1-git-send-email-iamjoonsoo.kim@lge.com> <1472447255-10584-2-git-send-email-iamjoonsoo.kim@lge.com> <87sht0y1rq.fsf@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87sht0y1rq.fsf@linux.vnet.ibm.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Sep 16, 2016 at 08:44:17AM +0530, Aneesh Kumar K.V wrote: > js1304@gmail.com writes: > > > 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. > > > > Signed-off-by: Joonsoo Kim > > --- > > include/linux/mmzone.h | 2 +- > > mm/page_alloc.c | 7 ++++--- > > 2 files changed, 5 insertions(+), 4 deletions(-) > > > > diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h > > index d572b78..e3f39af 100644 > > --- a/include/linux/mmzone.h > > +++ b/include/linux/mmzone.h > > @@ -877,7 +877,7 @@ 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 4f7d5d7..a8310de 100644 > > --- a/mm/page_alloc.c > > +++ b/mm/page_alloc.c > > @@ -198,17 +198,18 @@ static void __free_pages_ok(struct page *page, unsigned int order); > > * 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, > > #endif > > #ifdef CONFIG_ZONE_DMA32 > > 256, > > #endif > > -#ifdef CONFIG_HIGHMEM > > 32, > > +#ifdef CONFIG_HIGHMEM > > + INT_MAX, > > #endif > > - 32, > > + INT_MAX, > > }; > > > > EXPORT_SYMBOL(totalram_pages); > > -- > > 1.9.1 > > We can also do things like below to make it readable ? > > #ifdef CONFIG_ZONE_DMA > [ZONE_DMA] = 256, > #endif It looks more readable! I will change it. > > Reviewed-by: Aneesh Kumar K.V Thanks!