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=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 88A41C433DF for ; Mon, 6 Jul 2020 06:41:58 +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 F41CB2073E for ; Mon, 6 Jul 2020 06:41:57 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F41CB2073E 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 4B0bZq3NVwzDqhH for ; Mon, 6 Jul 2020 16:41:55 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=none (no SPF record) smtp.mailfrom=linux.vnet.ibm.com (client-ip=148.163.158.5; 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 (mx0b-001b2d01.pphosted.com [148.163.158.5]) (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 4B0bXz61t1zDqbc for ; Mon, 6 Jul 2020 16:40:19 +1000 (AEST) 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 0666VOxM102852; Mon, 6 Jul 2020 02:40:13 -0400 Received: from ppma04fra.de.ibm.com (6a.4a.5195.ip4.static.sl-reverse.com [149.81.74.106]) by mx0b-001b2d01.pphosted.com with ESMTP id 322nxwysb0-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 06 Jul 2020 02:40:13 -0400 Received: from pps.filterd (ppma04fra.de.ibm.com [127.0.0.1]) by ppma04fra.de.ibm.com (8.16.0.42/8.16.0.42) with SMTP id 0666FGa5015484; Mon, 6 Jul 2020 06:40:11 GMT Received: from b06cxnps4075.portsmouth.uk.ibm.com (d06relay12.portsmouth.uk.ibm.com [9.149.109.197]) by ppma04fra.de.ibm.com with ESMTP id 322hd7s05j-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 06 Jul 2020 06:40:11 +0000 Received: from d06av22.portsmouth.uk.ibm.com (d06av22.portsmouth.uk.ibm.com [9.149.105.58]) by b06cxnps4075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 0666e87K55246962 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 6 Jul 2020 06:40:08 GMT Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id AE38C4C046; Mon, 6 Jul 2020 06:40:07 +0000 (GMT) Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 552074C04A; Mon, 6 Jul 2020 06:40:06 +0000 (GMT) Received: from srikart450.in.ibm.com (unknown [9.102.3.252]) by d06av22.portsmouth.uk.ibm.com (Postfix) with ESMTP; Mon, 6 Jul 2020 06:40:06 +0000 (GMT) From: Srikar Dronamraju To: Michael Ellerman Subject: [PATCH] powerpc/numa: Restrict possible nodes based on platform Date: Mon, 6 Jul 2020 12:10:02 +0530 Message-Id: <20200706064002.14848-1-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=2020-07-06_03:2020-07-06, 2020-07-06 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxscore=0 bulkscore=0 phishscore=0 priorityscore=1501 lowpriorityscore=0 impostorscore=0 adultscore=0 malwarescore=0 spamscore=0 mlxlogscore=999 suspectscore=2 clxscore=1011 cotscore=-2147483648 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2004280000 definitions=main-2007060049 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 , linuxppc-dev , Srikar Dronamraju , Bharata B Rao 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 Signed-off-by: Srikar Dronamraju --- arch/powerpc/mm/numa.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c index 9fcf2d195830..3d55cef1a2dc 100644 --- a/arch/powerpc/mm/numa.c +++ b/arch/powerpc/mm/numa.c @@ -897,7 +897,7 @@ static void __init find_possible_nodes(void) return; if (of_property_read_u32_index(rtas, - "ibm,max-associativity-domains", + "ibm,current-associativity-domains", min_common_depth, &numnodes)) goto out; -- 2.18.2