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=-9.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 19242C54E4A for ; Tue, 12 May 2020 13:30:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ECB39206DD for ; Tue, 12 May 2020 13:30:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730097AbgELNab (ORCPT ); Tue, 12 May 2020 09:30:31 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:35188 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726891AbgELNab (ORCPT ); Tue, 12 May 2020 09:30:31 -0400 Received: from pps.filterd (m0098420.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 04CD4erx011485; Tue, 12 May 2020 09:30:10 -0400 Received: from pps.reinject (localhost [127.0.0.1]) by mx0b-001b2d01.pphosted.com with ESMTP id 30yv20sce2-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 12 May 2020 09:30:10 -0400 Received: from m0098420.ppops.net (m0098420.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.36/8.16.0.36) with SMTP id 04CD5kj2013895; Tue, 12 May 2020 09:30:10 -0400 Received: from ppma03fra.de.ibm.com (6b.4a.5195.ip4.static.sl-reverse.com [149.81.74.107]) by mx0b-001b2d01.pphosted.com with ESMTP id 30yv20sccu-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 12 May 2020 09:30:09 -0400 Received: from pps.filterd (ppma03fra.de.ibm.com [127.0.0.1]) by ppma03fra.de.ibm.com (8.16.0.27/8.16.0.27) with SMTP id 04CDL6oC024738; Tue, 12 May 2020 13:30:08 GMT Received: from b06cxnps3074.portsmouth.uk.ibm.com (d06relay09.portsmouth.uk.ibm.com [9.149.109.194]) by ppma03fra.de.ibm.com with ESMTP id 30wm56anbd-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 12 May 2020 13:30:08 +0000 Received: from d06av24.portsmouth.uk.ibm.com (d06av24.portsmouth.uk.ibm.com [9.149.105.60]) by b06cxnps3074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 04CDU5DL48627818 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 12 May 2020 13:30:05 GMT Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id BA2BC42056; Tue, 12 May 2020 13:30:05 +0000 (GMT) Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 770434204D; Tue, 12 May 2020 13:29:58 +0000 (GMT) Received: from srikart450.in.ibm.com (unknown [9.199.47.102]) by d06av24.portsmouth.uk.ibm.com (Postfix) with ESMTP; Tue, 12 May 2020 13:29:58 +0000 (GMT) From: Srikar Dronamraju To: Andrew Morton Cc: Srikar Dronamraju , linuxppc-dev@lists.ozlabs.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Michal Hocko , Mel Gorman , Vlastimil Babka , "Kirill A. Shutemov" , Christopher Lameter , Michael Ellerman , Linus Torvalds , Gautham R Shenoy , Satheesh Rajendran , David Hildenbrand Subject: [PATCH v4 3/3] mm/page_alloc: Keep memoryless cpuless node 0 offline Date: Tue, 12 May 2020 18:59:37 +0530 Message-Id: <20200512132937.19295-4-srikar@linux.vnet.ibm.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200512132937.19295-1-srikar@linux.vnet.ibm.com> References: <20200512132937.19295-1-srikar@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.216,18.0.676 definitions=2020-05-12_03:2020-05-11,2020-05-12 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 lowpriorityscore=0 mlxscore=0 suspectscore=0 bulkscore=0 clxscore=1015 spamscore=0 phishscore=0 priorityscore=1501 mlxlogscore=999 adultscore=0 impostorscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2003020000 definitions=main-2005120094 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Currently Linux kernel with CONFIG_NUMA on a system with multiple possible nodes, marks node 0 as online at boot. However in practice, there are systems which have node 0 as memoryless and cpuless. This can cause numa_balancing to be enabled on systems with only one node with memory and CPUs. The existence of this dummy node which is cpuless and memoryless node can confuse users/scripts looking at output of lscpu / numactl. By marking, N_ONLINE as NODE_MASK_NONE, lets stop assuming that Node 0 is always online. v5.7-rc3 available: 2 nodes (0,2) node 0 cpus: node 0 size: 0 MB node 0 free: 0 MB node 2 cpus: 0 1 2 3 4 5 6 7 node 2 size: 32625 MB node 2 free: 31490 MB node distances: node 0 2 0: 10 20 2: 20 10 proc and sys files ------------------ /sys/devices/system/node/online: 0,2 /proc/sys/kernel/numa_balancing: 1 /sys/devices/system/node/has_cpu: 2 /sys/devices/system/node/has_memory: 2 /sys/devices/system/node/has_normal_memory: 2 /sys/devices/system/node/possible: 0-31 v5.7-rc3 + patch ------------------ available: 1 nodes (2) node 2 cpus: 0 1 2 3 4 5 6 7 node 2 size: 32625 MB node 2 free: 31487 MB node distances: node 2 2: 10 proc and sys files ------------------ /sys/devices/system/node/online: 2 /proc/sys/kernel/numa_balancing: 0 /sys/devices/system/node/has_cpu: 2 /sys/devices/system/node/has_memory: 2 /sys/devices/system/node/has_normal_memory: 2 /sys/devices/system/node/possible: 0-31 Note: On Powerpc, cpu_to_node of possible but not present cpus would previously return 0. Hence this commit depends on commit ("powerpc/numa: Set numa_node for all possible cpus") and commit ("powerpc/numa: Prefer node id queried from vphn"). Without the 2 commits, Powerpc system might crash. Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org Cc: Michal Hocko Cc: Mel Gorman Cc: Vlastimil Babka Cc: "Kirill A. Shutemov" Cc: Christopher Lameter Cc: Michael Ellerman Cc: Andrew Morton Cc: Linus Torvalds Cc: Gautham R Shenoy Cc: Satheesh Rajendran Cc: David Hildenbrand Signed-off-by: Srikar Dronamraju --- Changelog v1:->v2: - Rebased to v5.7-rc3 Link v2: https://lore.kernel.org/linuxppc-dev/20200428093836.27190-1-srikar@linux.vnet.ibm.com/t/#u mm/page_alloc.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 69827d4..03b8959 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -116,8 +116,10 @@ struct pcpu_drain { */ nodemask_t node_states[NR_NODE_STATES] __read_mostly = { [N_POSSIBLE] = NODE_MASK_ALL, +#ifdef CONFIG_NUMA + [N_ONLINE] = NODE_MASK_NONE, +#else [N_ONLINE] = { { [0] = 1UL } }, -#ifndef CONFIG_NUMA [N_NORMAL_MEMORY] = { { [0] = 1UL } }, #ifdef CONFIG_HIGHMEM [N_HIGH_MEMORY] = { { [0] = 1UL } }, -- 1.8.3.1