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 CABFCC433FE for ; Mon, 28 Mar 2022 07:23:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236767AbiC1HZf (ORCPT ); Mon, 28 Mar 2022 03:25:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40632 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231468AbiC1HZd (ORCPT ); Mon, 28 Mar 2022 03:25:33 -0400 Received: from szxga08-in.huawei.com (szxga08-in.huawei.com [45.249.212.255]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 622BA205D8 for ; Mon, 28 Mar 2022 00:23:53 -0700 (PDT) Received: from canpemm500002.china.huawei.com (unknown [172.30.72.56]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4KRkh80r80z1GD2V; Mon, 28 Mar 2022 15:23:36 +0800 (CST) Received: from [10.174.177.76] (10.174.177.76) by canpemm500002.china.huawei.com (7.192.104.244) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.21; Mon, 28 Mar 2022 15:23:50 +0800 Subject: Re: [PATCH 2/2] mm/vmscan: make sure wakeup_kswapd with managed zone To: "Huang, Ying" , Wei Yang CC: , , , References: <20220327024101.10378-1-richard.weiyang@gmail.com> <20220327024101.10378-2-richard.weiyang@gmail.com> <8735j2opd9.fsf@yhuang6-desk2.ccr.corp.intel.com> From: Miaohe Lin Message-ID: <8ff6f619-e04a-d785-fa9a-6822c04d4ee1@huawei.com> Date: Mon, 28 Mar 2022 15:23:49 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 MIME-Version: 1.0 In-Reply-To: <8735j2opd9.fsf@yhuang6-desk2.ccr.corp.intel.com> Content-Type: text/plain; charset="windows-1252" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.177.76] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To canpemm500002.china.huawei.com (7.192.104.244) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2022/3/28 9:08, Huang, Ying wrote: > Hi, Wei, > > Wei Yang writes: > >> wakeup_kswapd() only wake up kswapd when the zone is managed. >> >> For two callers of wakeup_kswapd(), they are node perspective. >> >> * wake_all_kswapds >> * numamigrate_isolate_page >> >> If we picked up a !managed zone, this is not we expected. >> >> This patch makes sure we pick up a managed zone for wakeup_kswapd(). >> >> Signed-off-by: Wei Yang >> --- >> mm/migrate.c | 2 +- >> mm/page_alloc.c | 2 ++ >> 2 files changed, 3 insertions(+), 1 deletion(-) >> >> diff --git a/mm/migrate.c b/mm/migrate.c >> index 3d60823afd2d..c4b654c0bdf0 100644 >> --- a/mm/migrate.c >> +++ b/mm/migrate.c >> @@ -2046,7 +2046,7 @@ static int numamigrate_isolate_page(pg_data_t *pgdat, struct page *page) >> if (!(sysctl_numa_balancing_mode & NUMA_BALANCING_MEMORY_TIERING)) >> return 0; >> for (z = pgdat->nr_zones - 1; z >= 0; z--) { >> - if (populated_zone(pgdat->node_zones + z)) >> + if (managed_zone(pgdat->node_zones + z)) > > This looks good to me! Thanks! It seems that we can replace > populated_zone() in migrate_balanced_pgdat() too. Right? This patch looks good to me too. Thanks! BTW: This makes me remember the bewilderment when I read the relevant code. It's very kind of you if you could tell me the difference between managed_zone and populated_zone. IIUC, when the caller relies on the activity from buddy system, managed_zone should always be used. I think there're many places like compaction need to use managed_zone but populated_zone is used now. They might need to change to use managed_zone too. Or am I miss something? Many Thanks. :) > >> break; >> } >> wakeup_kswapd(pgdat->node_zones + z, 0, order, ZONE_MOVABLE); >> diff --git a/mm/page_alloc.c b/mm/page_alloc.c >> index 4c0c4ef94ba0..6656c2d06e01 100644 >> --- a/mm/page_alloc.c >> +++ b/mm/page_alloc.c >> @@ -4674,6 +4674,8 @@ static void wake_all_kswapds(unsigned int order, gfp_t gfp_mask, >> >> for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, highest_zoneidx, >> ac->nodemask) { >> + if (!managed_zone(zone)) >> + continue; >> if (last_pgdat != zone->zone_pgdat) >> wakeup_kswapd(zone, gfp_mask, order, highest_zoneidx); >> last_pgdat = zone->zone_pgdat; > > Best Regards, > Huang, Ying > > . >