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 X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 115C5C433E0 for ; Wed, 1 Jul 2020 00:48:41 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id CFCBB20781 for ; Wed, 1 Jul 2020 00:48:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CFCBB20781 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 7C04B6B0088; Tue, 30 Jun 2020 20:48:40 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 7710B6B009A; Tue, 30 Jun 2020 20:48:40 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 65D216B00AF; Tue, 30 Jun 2020 20:48:40 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0178.hostedemail.com [216.40.44.178]) by kanga.kvack.org (Postfix) with ESMTP id 4F8086B0088 for ; Tue, 30 Jun 2020 20:48:40 -0400 (EDT) Received: from smtpin25.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 0E6F78248047 for ; Wed, 1 Jul 2020 00:48:40 +0000 (UTC) X-FDA: 76987671600.25.news67_160218526e7c Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin25.hostedemail.com (Postfix) with ESMTP id D9E3C1804E3A1 for ; Wed, 1 Jul 2020 00:48:39 +0000 (UTC) X-HE-Tag: news67_160218526e7c X-Filterd-Recvd-Size: 4074 Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by imf28.hostedemail.com (Postfix) with ESMTP for ; Wed, 1 Jul 2020 00:48:37 +0000 (UTC) IronPort-SDR: JmuVpyUba+W5/HfUPOLrNUm1tChq5FC3PDzBfQShVr7NHUOBlclbR7Lrv0JS8/f9z2QmfXk7za r8IX2CmJRXoQ== X-IronPort-AV: E=McAfee;i="6000,8403,9668"; a="164426517" X-IronPort-AV: E=Sophos;i="5.75,298,1589266800"; d="scan'208";a="164426517" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Jun 2020 17:48:34 -0700 IronPort-SDR: 7uQbbDbavB+IgSwg+d5bR+aRJ7G8ZlZcCA6NpkA6LEfKLyr+Jz6dawj0KC6OlDv2W2wM51K7Va 6jJCjumgaKMQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.75,298,1589266800"; d="scan'208";a="454807974" Received: from yhuang-dev.sh.intel.com (HELO yhuang-dev) ([10.239.159.23]) by orsmga005.jf.intel.com with ESMTP; 30 Jun 2020 17:48:32 -0700 From: "Huang\, Ying" To: Yang Shi Cc: Dave Hansen , , , , Subject: Re: [RFC][PATCH 8/8] mm/numa: new reclaim mode to enable reclaim-based migration References: <20200629234503.749E5340@viggo.jf.intel.com> <20200629234517.A7EC4BD3@viggo.jf.intel.com> <87v9j9ow3a.fsf@yhuang-dev.intel.com> <29c67873-3cb9-e121-382c-9b81491016bc@linux.alibaba.com> Date: Wed, 01 Jul 2020 08:48:31 +0800 In-Reply-To: <29c67873-3cb9-e121-382c-9b81491016bc@linux.alibaba.com> (Yang Shi's message of "Tue, 30 Jun 2020 10:50:30 -0700") Message-ID: <87mu4knjq8.fsf@yhuang-dev.intel.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=ascii X-Rspamd-Queue-Id: D9E3C1804E3A1 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam02 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Hi, Yang, Yang Shi writes: >>> diff -puN mm/vmscan.c~enable-numa-demotion mm/vmscan.c >>> --- a/mm/vmscan.c~enable-numa-demotion 2020-06-29 16:35:01.017312549 -0700 >>> +++ b/mm/vmscan.c 2020-06-29 16:35:01.023312549 -0700 >>> @@ -4165,9 +4165,10 @@ int node_reclaim_mode __read_mostly; >>> * These bit locations are exposed in the vm.zone_reclaim_mode sysctl >>> * ABI. New bits are OK, but existing bits can never change. >>> */ >>> -#define RECLAIM_RSVD (1<<0) /* (currently ignored/unused) */ >>> -#define RECLAIM_WRITE (1<<1) /* Writeout pages during reclaim */ >>> -#define RECLAIM_UNMAP (1<<2) /* Unmap pages during reclaim */ >>> +#define RECLAIM_RSVD (1<<0) /* (currently ignored/unused) */ >>> +#define RECLAIM_WRITE (1<<1) /* Writeout pages during reclaim */ >>> +#define RECLAIM_UNMAP (1<<2) /* Unmap pages during reclaim */ >>> +#define RECLAIM_MIGRATE (1<<3) /* Migrate pages during reclaim */ >>> /* >>> * Priority for NODE_RECLAIM. This determines the fraction of pages >> I found that RECLAIM_MIGRATE is defined but never referenced in the >> patch. >> >> If my understanding of the code were correct, shrink_do_demote_mapping() >> is called by shrink_page_list(), which is used by kswapd and direct >> reclaim. So as long as the persistent memory node is onlined, >> reclaim-based migration will be enabled regardless of node reclaim mode. > > It looks so according to the code. But the intention of a new node > reclaim mode is to do migration on reclaim *only when* the > RECLAIM_MODE is enabled by the users. > > It looks the patch just clear the migration target node masks if the > memory is offlined. > > So, I'm supposed you need check if node_reclaim is enabled before > doing migration in shrink_page_list() and also need make node reclaim > to adopt the new mode. But why shouldn't we migrate in kswapd and direct reclaim? I think that we may need a way to control it, but shouldn't disable it unconditionally. > Please refer to > https://lore.kernel.org/linux-mm/1560468577-101178-6-git-send-email-yang.shi@linux.alibaba.com/ > Best Regards, Huang, Ying