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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 76A9DC282DD for ; Thu, 18 Apr 2019 19:02:23 +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 EDD282183F for ; Thu, 18 Apr 2019 19:02:22 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EDD282183F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.ibm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 44lT4X6wMFzDqSp for ; Fri, 19 Apr 2019 05:02:20 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=linux.ibm.com (client-ip=148.163.158.5; helo=mx0a-001b2d01.pphosted.com; envelope-from=nathanl@linux.ibm.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=linux.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 44lSyd50Q0zDqSB for ; Fri, 19 Apr 2019 04:57:10 +1000 (AEST) Received: from pps.filterd (m0098416.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x3IInUnu153130 for ; Thu, 18 Apr 2019 14:57:06 -0400 Received: from e14.ny.us.ibm.com (e14.ny.us.ibm.com [129.33.205.204]) by mx0b-001b2d01.pphosted.com with ESMTP id 2rxv28rfj8-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Thu, 18 Apr 2019 14:57:06 -0400 Received: from localhost by e14.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Thu, 18 Apr 2019 19:57:03 +0100 Received: from b01ledav003.gho.pok.ibm.com (b01ledav003.gho.pok.ibm.com [9.57.199.108]) by b01cxnp23033.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x3IIv00V33161256 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 18 Apr 2019 18:57:00 GMT Received: from b01ledav003.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 7EA7EB2064; Thu, 18 Apr 2019 18:57:00 +0000 (GMT) Received: from b01ledav003.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 586CEB205F; Thu, 18 Apr 2019 18:57:00 +0000 (GMT) Received: from localhost (unknown [9.85.201.6]) by b01ledav003.gho.pok.ibm.com (Postfix) with ESMTP; Thu, 18 Apr 2019 18:57:00 +0000 (GMT) From: Nathan Lynch To: linuxppc-dev@lists.ozlabs.org Subject: [PATCH 2/2] powerpc/numa: document topology_updates_enabled, disable by default Date: Thu, 18 Apr 2019 13:56:58 -0500 X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190418185658.29751-1-nathanl@linux.ibm.com> References: <20190418185658.29751-1-nathanl@linux.ibm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 x-cbid: 19041818-0052-0000-0000-000003AE28F0 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00010951; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000285; SDB=6.01190966; UDB=6.00624129; IPR=6.00971763; MB=3.00026504; MTD=3.00000008; XFM=3.00000015; UTC=2019-04-18 18:57:05 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19041818-0053-0000-0000-0000608CAA64 Message-Id: <20190418185658.29751-3-nathanl@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2019-04-18_09:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1904180116 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: srikar.dronamraju@in.ibm.com, mmc@linux.ibm.com, mwb@linux.ibm.com, julietk@linux.ibm.com Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" Changing the NUMA associations for CPUs and memory at runtime is basically unsupported by the core mm, scheduler etc. We see all manner of crashes, warnings and instability when the pseries code tries to do this. Disable this behavior by default, and document the switch a bit. Signed-off-by: Nathan Lynch --- arch/powerpc/mm/numa.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c index 48c9a97eb2c3..71af382ce1d5 100644 --- a/arch/powerpc/mm/numa.c +++ b/arch/powerpc/mm/numa.c @@ -908,16 +908,22 @@ static int __init early_numa(char *p) } early_param("numa", early_numa); -static bool topology_updates_enabled = true; +/* + * The platform can inform us through one of several mechanisms + * (post-migration device tree updates, PRRN or VPHN) that the NUMA + * assignment of a resource has changed. This controls whether we act + * on that. Disabled by default. + */ +static bool topology_updates_enabled; static int __init early_topology_updates(char *p) { if (!p) return 0; - if (!strcmp(p, "off")) { - pr_info("Disabling topology updates\n"); - topology_updates_enabled = false; + if (!strcmp(p, "on")) { + pr_warn("Caution: enabling topology updates\n"); + topology_updates_enabled = true; } return 0; -- 2.20.1