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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,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 072C4C433E4 for ; Mon, 29 Jun 2020 23:48:44 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id BF1EF20780 for ; Mon, 29 Jun 2020 23:48:43 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BF1EF20780 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 0C9F68D001B; Mon, 29 Jun 2020 19:48:39 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 07AD18D001D; Mon, 29 Jun 2020 19:48:39 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id EAB1C8D001B; Mon, 29 Jun 2020 19:48:38 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0147.hostedemail.com [216.40.44.147]) by kanga.kvack.org (Postfix) with ESMTP id D5F128D001D for ; Mon, 29 Jun 2020 19:48:38 -0400 (EDT) Received: from smtpin11.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 9E633180AD804 for ; Mon, 29 Jun 2020 23:48:38 +0000 (UTC) X-FDA: 76983891516.11.women73_47017a626e73 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin11.hostedemail.com (Postfix) with ESMTP id E4A50180F8B86 for ; Mon, 29 Jun 2020 23:48:31 +0000 (UTC) X-HE-Tag: women73_47017a626e73 X-Filterd-Recvd-Size: 3619 Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) by imf40.hostedemail.com (Postfix) with ESMTP for ; Mon, 29 Jun 2020 23:48:31 +0000 (UTC) IronPort-SDR: mweNTho7ZybSJERSA8zgDDNOFKqajCcZuzX+JAmtY2ubPLTH+54rIVPi5vpRuwcOqtlw1r3m0d wbVVDOY9uQzQ== X-IronPort-AV: E=McAfee;i="6000,8403,9666"; a="211173252" X-IronPort-AV: E=Sophos;i="5.75,296,1589266800"; d="scan'208";a="211173252" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 Jun 2020 16:48:29 -0700 IronPort-SDR: VRSKSVr09Pa/rZrlzH3Vjr4iagEfzf6Hd6WnqUdLcWNMFkdi8glBXAu3Kbl6/7mX0Gnyk6Vqgw g2B5KkqF6F4A== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.75,296,1589266800"; d="scan'208";a="320772112" Received: from viggo.jf.intel.com (HELO localhost.localdomain) ([10.54.77.144]) by FMSMGA003.fm.intel.com with ESMTP; 29 Jun 2020 16:48:29 -0700 Subject: [RFC][PATCH 1/8] mm/numa: node demotion data structure and lookup To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org,Dave Hansen ,yang.shi@linux.alibaba.com,rientjes@google.com,ying.huang@intel.com,dan.j.williams@intel.com From: Dave Hansen Date: Mon, 29 Jun 2020 16:45:05 -0700 References: <20200629234503.749E5340@viggo.jf.intel.com> In-Reply-To: <20200629234503.749E5340@viggo.jf.intel.com> Message-Id: <20200629234505.6ABCBDF4@viggo.jf.intel.com> X-Rspamd-Queue-Id: E4A50180F8B86 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam03 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: From: Dave Hansen Prepare for the kernel to auto-migrate pages to other memory nodes with a user defined node migration table. This allows creating single migration target for each NUMA node to enable the kernel to do NUMA page migrations instead of simply reclaiming colder pages. A node with no target is a "terminal node", so reclaim acts normally there. The migration target does not fundamentally _need_ to be a single node, but this implementation starts there to limit complexity. If you consider the migration path as a graph, cycles (loops) in the graph are disallowed. This avoids wasting resources by constantly migrating (A->B, B->A, A->B ...). The expectation is that cycles will never be allowed. Signed-off-by: Dave Hansen Cc: Yang Shi Cc: David Rientjes Cc: Huang Ying Cc: Dan Williams --- b/mm/migrate.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff -puN mm/migrate.c~0006-node-Define-and-export-memory-migration-path mm/migrate.c --- a/mm/migrate.c~0006-node-Define-and-export-memory-migration-path 2020-06-29 16:34:36.849312609 -0700 +++ b/mm/migrate.c 2020-06-29 16:34:36.853312609 -0700 @@ -1159,6 +1159,29 @@ out: return rc; } +static int node_demotion[MAX_NUMNODES] = {[0 ... MAX_NUMNODES - 1] = NUMA_NO_NODE}; + +/** + * next_demotion_node() - Get the next node in the demotion path + * @node: The starting node to lookup the next node + * + * @returns: node id for next memory node in the demotion path hierarchy + * from @node; -1 if @node is terminal + */ +int next_demotion_node(int node) +{ + get_online_mems(); + while (true) { + node = node_demotion[node]; + if (node == NUMA_NO_NODE) + break; + if (node_online(node)) + break; + } + put_online_mems(); + return node; +} + /* * gcc 4.7 and 4.8 on arm get an ICEs when inlining unmap_and_move(). Work * around it. _