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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 F19ABC7618F for ; Thu, 18 Jul 2019 19:52:57 +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 7CF8A208C0 for ; Thu, 18 Jul 2019 19:52:57 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7CF8A208C0 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 45qPtv1bZWzDqGq for ; Fri, 19 Jul 2019 05:52:55 +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 45qPlz5hmJzDqdP for ; Fri, 19 Jul 2019 05:46:55 +1000 (AEST) Received: from pps.filterd (m0098417.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x6IJiCDJ013338 for ; Thu, 18 Jul 2019 15:46:52 -0400 Received: from e32.co.us.ibm.com (e32.co.us.ibm.com [32.97.110.150]) by mx0a-001b2d01.pphosted.com with ESMTP id 2ttvjvxat6-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Thu, 18 Jul 2019 15:46:52 -0400 Received: from localhost by e32.co.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 Jul 2019 20:46:50 +0100 Received: from b03ledav006.gho.boulder.ibm.com (b03ledav006.gho.boulder.ibm.com [9.17.130.237]) by b03cxnp08026.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x6IJknW025362724 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Thu, 18 Jul 2019 19:46:49 GMT Received: from b03ledav006.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 282E3C6057 for ; Thu, 18 Jul 2019 19:46:49 +0000 (GMT) Received: from b03ledav006.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 0F823C6055 for ; Thu, 18 Jul 2019 19:46:48 +0000 (GMT) Received: from localhost (unknown [9.41.101.192]) by b03ledav006.gho.boulder.ibm.com (Postfix) with ESMTP for ; Thu, 18 Jul 2019 19:46:48 +0000 (GMT) From: Nathan Lynch To: linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH 1/2] powerpc/rtas: use device model APIs and serialization during LPM In-Reply-To: <20190718192940.16103-2-nathanl@linux.ibm.com> References: <20190718192940.16103-1-nathanl@linux.ibm.com> <20190718192940.16103-2-nathanl@linux.ibm.com> Date: Thu, 18 Jul 2019 14:46:43 -0500 MIME-Version: 1.0 Content-Type: text/plain X-TM-AS-GCONF: 00 x-cbid: 19071819-0004-0000-0000-0000152C07A8 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00011453; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000287; SDB=6.01234063; UDB=6.00650301; IPR=6.01015390; MB=3.00027784; MTD=3.00000008; XFM=3.00000015; UTC=2019-07-18 19:46:51 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19071819-0005-0000-0000-00008C853689 Message-Id: <87tvbj2kik.fsf@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2019-07-18_09:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=3 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=880 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1907180202 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: , Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" Nathan Lynch writes: > During LPAR migration, cpu hotplug and migration operations can > interleave like so: > > cd /sys/devices/system/cpu/cpu7/ | drmgr -m -c pmig -p pre \ > echo 0 > online | -s 0xd7a884f83d830e6d -t 19 \ > echo 1 > online | -n -d 1 5 > ---------------------------------+------------------------------------------- > online_store() { | > device_offline() { | > cpu_subsys_offline() { | > cpu_down(7); | > } | > dev->offline = true; | > } | migration_store() { > } | rtas_ibm_suspend_me() { > | rtas_online_cpus_mask() { > | cpu_up(7); > | } > | cpu_hotplug_disable(); > | on_each_cpu(rtas_percpu_suspend_me()); > | cpu_hotplug_enable(); > online_store() { | > device_online() { | > cpu_subsys_online() { | > cpu_up(7); | > } | > dev->offline = false; | > } | rtas_offline_cpus_mask() { > } | rtas_cpu_state_change_mask() { > | cpu_down(7); > | } > | } > | } > | } Actually I think this isn't a correct depiction of the race. I'll rewrite and resend.