From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3DADFEB64D7 for ; Wed, 21 Jun 2023 10:01:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230325AbjFUKBt (ORCPT ); Wed, 21 Jun 2023 06:01:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53096 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232157AbjFUKAg (ORCPT ); Wed, 21 Jun 2023 06:00:36 -0400 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3067C10F1 for ; Wed, 21 Jun 2023 03:00:28 -0700 (PDT) Received: from dggpemm100001.china.huawei.com (unknown [172.30.72.55]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4QmJsG4D2czqTl7; Wed, 21 Jun 2023 18:00:18 +0800 (CST) Received: from [10.174.177.243] (10.174.177.243) by dggpemm100001.china.huawei.com (7.185.36.93) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.27; Wed, 21 Jun 2023 18:00:26 +0800 Message-ID: <2fb1f6dd-afea-caf5-a94b-6915b21258a4@huawei.com> Date: Wed, 21 Jun 2023 18:00:25 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.10.1 Subject: Re: [PATCH v3] mm/min_free_kbytes: modify min_free_kbytes calculation rules Content-Language: en-US To: liuq , CC: , , , mawupeng 00564683 , Mel Gorman References: <20230621092048.5242-1-liuq131@chinatelecom.cn> From: Kefeng Wang In-Reply-To: <20230621092048.5242-1-liuq131@chinatelecom.cn> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.177.243] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To dggpemm100001.china.huawei.com (7.185.36.93) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Liuq, On 2023/6/21 17:20, liuq wrote: > The current calculation of min_free_kbytes only uses ZONE_DMA and > ZONE_NORMAL pages,but the ZONE_MOVABLE zone->_watermark[WMARK_MIN] > will also divide part of min_free_kbytes.This will cause the min > watermark of ZONE_NORMAL to be too small in the presence of ZONE_MOVEABLE. > > __GFP_HIGH and PF_MEMALLOC allocations usually don't need movable > zone pages, so just like ZONE_HIGHMEM, cap pages_min to a small > value in __setup_per_zone_wmarks. > > On my testing machine with 16GB of memory (transparent hugepage is > turned off by default, and movablecore=12G is configured) > The following is a comparative test data of watermark_min > > no patch add patch > ZONE_DMA 1 8 > ZONE_DMA32 151 709 > ZONE_NORMAL 233 1113 > ZONE_MOVABLE 1434 128 > min_free_kbytes 7288 7326 > We see this issue and do the same change[1], and we add a per zone watermark configuration too, but both of them is not accepted, let's add Mel and wupeng to see more comments. [1]https://lore.kernel.org/linux-mm/20220905032858.1462927-1-mawupeng1@huawei.com/ > Signed-off-by: liuq > --- > mm/page_alloc.c | 12 ++++++------ > 1 file changed, 6 insertions(+), 6 deletions(-) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index 47421bedc12b..590ed8725e09 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -6362,9 +6362,9 @@ static void __setup_per_zone_wmarks(void) > struct zone *zone; > unsigned long flags; > > - /* Calculate total number of !ZONE_HIGHMEM pages */ > + /* Calculate total number of !ZONE_HIGHMEM and !ZONE_MOVABLE pages */ > for_each_zone(zone) { > - if (!is_highmem(zone)) > + if (!is_highmem(zone) && zone_idx(zone) != ZONE_MOVABLE) > lowmem_pages += zone_managed_pages(zone); > } > > @@ -6374,15 +6374,15 @@ static void __setup_per_zone_wmarks(void) > spin_lock_irqsave(&zone->lock, flags); > tmp = (u64)pages_min * zone_managed_pages(zone); > do_div(tmp, lowmem_pages); > - if (is_highmem(zone)) { > + if (is_highmem(zone) || zone_idx(zone) == ZONE_MOVABLE) { > /* > * __GFP_HIGH and PF_MEMALLOC allocations usually don't > - * need highmem pages, so cap pages_min to a small > - * value here. > + * need highmem and movable zones pages, so cap pages_min > + * to a small value here. > * > * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN) > * deltas control async page reclaim, and so should > - * not be capped for highmem. > + * not be capped for highmem and movable zones. > */ > unsigned long min_pages; >