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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham 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 7805BC433E0 for ; Tue, 7 Jul 2020 14:11:47 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 2F8E4206E2 for ; Tue, 7 Jul 2020 14:11:47 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2F8E4206E2 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.vnet.ibm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 4B1PWK6NKJzDqND for ; Wed, 8 Jul 2020 00:11:41 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=none (no SPF record) smtp.mailfrom=linux.vnet.ibm.com (client-ip=148.163.156.1; helo=mx0a-001b2d01.pphosted.com; envelope-from=srikar@linux.vnet.ibm.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=fail (p=none dis=none) header.from=linux.vnet.ibm.com Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4B1PQ046kqzDqFZ for ; Wed, 8 Jul 2020 00:07:04 +1000 (AEST) Received: from pps.filterd (m0098396.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 067E3BN5085475; Tue, 7 Jul 2020 10:06:58 -0400 Received: from ppma05fra.de.ibm.com (6c.4a.5195.ip4.static.sl-reverse.com [149.81.74.108]) by mx0a-001b2d01.pphosted.com with ESMTP id 324hfr0hmm-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 07 Jul 2020 10:06:55 -0400 Received: from pps.filterd (ppma05fra.de.ibm.com [127.0.0.1]) by ppma05fra.de.ibm.com (8.16.0.42/8.16.0.42) with SMTP id 067E4pJw019886; Tue, 7 Jul 2020 14:06:53 GMT Received: from b06cxnps4076.portsmouth.uk.ibm.com (d06relay13.portsmouth.uk.ibm.com [9.149.109.198]) by ppma05fra.de.ibm.com with ESMTP id 322hd81sb6-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 07 Jul 2020 14:06:53 +0000 Received: from d06av21.portsmouth.uk.ibm.com (d06av21.portsmouth.uk.ibm.com [9.149.105.232]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 067E6ofj42532984 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 7 Jul 2020 14:06:50 GMT Received: from d06av21.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 8DDCA52057; Tue, 7 Jul 2020 14:06:50 +0000 (GMT) Received: from srikart450.in.ibm.com (unknown [9.102.0.236]) by d06av21.portsmouth.uk.ibm.com (Postfix) with ESMTP id DBC3652054; Tue, 7 Jul 2020 14:06:48 +0000 (GMT) From: Srikar Dronamraju To: Michael Ellerman Subject: [PATCH v2] powerpc/numa: Restrict possible nodes based on platform Date: Tue, 7 Jul 2020 19:36:44 +0530 Message-Id: <20200707140644.7241-1-srikar@linux.vnet.ibm.com> X-Mailer: git-send-email 2.17.1 X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235, 18.0.687 definitions=2020-07-07_08:2020-07-07, 2020-07-07 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 bulkscore=0 impostorscore=0 clxscore=1015 cotscore=-2147483648 lowpriorityscore=0 adultscore=0 mlxlogscore=999 priorityscore=1501 phishscore=0 mlxscore=0 spamscore=0 suspectscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2004280000 definitions=main-2007070105 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Nathan Lynch , Tyrel Datwyler , Srikar Dronamraju , Bharata B Rao , linuxppc-dev Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" As per PAPR, there are 2 device tree property ibm,max-associativity-domains (which defines the maximum number of domains that the firmware i.e PowerVM can support) and ibm,current-associativity-domains (which defines the maximum number of domains that the platform can support). Value of ibm,max-associativity-domains property is always greater than or equal to ibm,current-associativity-domains property. Powerpc currently uses ibm,max-associativity-domains property while setting the possible number of nodes. This is currently set at 32. However the possible number of nodes for a platform may be significantly less. Hence set the possible number of nodes based on ibm,current-associativity-domains property. $ lsprop /proc/device-tree/rtas/ibm,*associ*-domains /proc/device-tree/rtas/ibm,current-associativity-domains 00000005 00000001 00000002 00000002 00000002 00000010 /proc/device-tree/rtas/ibm,max-associativity-domains 00000005 00000001 00000008 00000020 00000020 00000100 $ cat /sys/devices/system/node/possible ##Before patch 0-31 $ cat /sys/devices/system/node/possible ##After patch 0-1 Note the maximum nodes this platform can support is only 2 but the possible nodes is set to 32. This is important because lot of kernel and user space code allocate structures for all possible nodes leading to a lot of memory that is allocated but not used. I ran a simple experiment to create and destroy 100 memory cgroups on boot on a 8 node machine (Power8 Alpine). Before patch free -k at boot total used free shared buff/cache available Mem: 523498176 4106816 518820608 22272 570752 516606720 Swap: 4194240 0 4194240 free -k after creating 100 memory cgroups total used free shared buff/cache available Mem: 523498176 4628416 518246464 22336 623296 516058688 Swap: 4194240 0 4194240 free -k after destroying 100 memory cgroups total used free shared buff/cache available Mem: 523498176 4697408 518173760 22400 627008 515987904 Swap: 4194240 0 4194240 After patch free -k at boot total used free shared buff/cache available Mem: 523498176 3969472 518933888 22272 594816 516731776 Swap: 4194240 0 4194240 free -k after creating 100 memory cgroups total used free shared buff/cache available Mem: 523498176 4181888 518676096 22208 640192 516496448 Swap: 4194240 0 4194240 free -k after destroying 100 memory cgroups total used free shared buff/cache available Mem: 523498176 4232320 518619904 22272 645952 516443264 Swap: 4194240 0 4194240 Observations: Fixed kernel takes 137344 kb (4106816-3969472) less to boot. Fixed kernel takes 309184 kb (4628416-4181888-137344) less to create 100 memcgs. Cc: Nathan Lynch Cc: Michael Ellerman Cc: linuxppc-dev@lists.ozlabs.org Cc: Anton Blanchard Cc: Bharata B Rao Cc: Tyrel Datwyler Signed-off-by: Srikar Dronamraju --- v1: https://lore.kernel.org/linuxppc-dev/20200706064002.14848-1-srikar@linux.vnet.ibm.com/t/#u Changelog v1->v2: Fallback to ibm,max-associativity-domains if ibm,current-associativity is not available. Suggested by Tyrel Datwyler. arch/powerpc/mm/numa.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c index 9fcf2d195830..fc7b0505bdd8 100644 --- a/arch/powerpc/mm/numa.c +++ b/arch/powerpc/mm/numa.c @@ -896,10 +896,19 @@ static void __init find_possible_nodes(void) if (!rtas) return; - if (of_property_read_u32_index(rtas, - "ibm,max-associativity-domains", + if (of_property_read_u32_index(rtas, "ibm,current-associativity-domains", + min_common_depth, &numnodes)) { + /* + * ibm,current-associativity-domains is a fairly recent + * property. If it doesn't exist, then fallback on + * ibm,max-associativity-domains. Current denotes what the + * platform can support compared to max which denotes what the + * Hypervisor can support. + */ + if (of_property_read_u32_index(rtas, "ibm,max-associativity-domains", min_common_depth, &numnodes)) - goto out; + goto out; + } for (i = 0; i < numnodes; i++) { if (!node_possible(i)) -- 2.18.2