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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3E78CEB64DA for ; Fri, 30 Jun 2023 03:42:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231915AbjF3DmG (ORCPT ); Thu, 29 Jun 2023 23:42:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44164 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229720AbjF3DmE (ORCPT ); Thu, 29 Jun 2023 23:42:04 -0400 Received: from mx0b-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 29A721FE3; Thu, 29 Jun 2023 20:42:03 -0700 (PDT) Received: from pps.filterd (m0353723.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 35U3XO0v022754; Fri, 30 Jun 2023 03:41:53 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=from : to : cc : subject : in-reply-to : references : date : message-id : mime-version : content-type; s=pp1; bh=B1CW1DrvWrT1T4qGGfA0jnCPLsgt+8lZqZbPxtbBKe4=; b=Q199RAYkh0GWA3nzuO29PoKN/jao/SbWBZHUJpXrFwFl95B2jo9emr7Zphh9T8Hu0W4/ KTW8G3DLkVB87HByfLJWV/ve/wdxHJrYzO7LiYT3YF3wIyw1j6IZAVUhn2+LR6yXVSjL ydQ1cVZaYyn8WH6m1xsHksQE5+CZffXTYuBLqtaLsKZBgHjXEmJj7ncOLxfNdFRMI/IN vQk0aw4LH++MtvAjiyTYyWFA2l9p8XXMToYd2vdxPooMkCUzehBjXLhXMrUH9CQR24Kz mqbTCN1WIvyHvHVqNW/HGMfYLV0gC0o5SnrS6dvb9RgM5f6obY1yQtkmRhTlHOUWqz+T kg== Received: from ppma03ams.nl.ibm.com (62.31.33a9.ip4.static.sl-reverse.com [169.51.49.98]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3rhq8108u0-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 30 Jun 2023 03:41:53 +0000 Received: from pps.filterd (ppma03ams.nl.ibm.com [127.0.0.1]) by ppma03ams.nl.ibm.com (8.17.1.19/8.17.1.19) with ESMTP id 35U2fQUQ029312; Fri, 30 Jun 2023 03:41:51 GMT Received: from smtprelay03.fra02v.mail.ibm.com ([9.218.2.224]) by ppma03ams.nl.ibm.com (PPS) with ESMTPS id 3rdr453wua-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 30 Jun 2023 03:41:51 +0000 Received: from smtpav01.fra02v.mail.ibm.com (smtpav01.fra02v.mail.ibm.com [10.20.54.100]) by smtprelay03.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 35U3flat18743834 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 30 Jun 2023 03:41:47 GMT Received: from smtpav01.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 878BF2004B; Fri, 30 Jun 2023 03:41:47 +0000 (GMT) Received: from smtpav01.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id ADD1F20043; Fri, 30 Jun 2023 03:41:45 +0000 (GMT) Received: from tarunpc (unknown [9.199.157.25]) by smtpav01.fra02v.mail.ibm.com (Postfix) with ESMTPS; Fri, 30 Jun 2023 03:41:45 +0000 (GMT) From: Tarun Sahu To: nvdimm@lists.linux.dev, linux-cxl@vger.kernel.org Cc: linux-kernel@vger.kernel.org, dave.jiang@intel.com, dan.j.williams@intel.com, vishal.l.verma@intel.com, aneesh.kumar@linux.ibm.com, jaypatel@linux.ibm.com Subject: Re: [PATCH v3] dax/kmem: Pass valid argument to memory_group_register_static In-Reply-To: <20230621155025.370672-1-tsahu@linux.ibm.com> References: <20230621155025.370672-1-tsahu@linux.ibm.com> Date: Fri, 30 Jun 2023 09:11:43 +0530 Message-ID: <87cz1daa6g.fsf@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: 91-uvh5JY-SRRCM4OE5_Vua_DkZ2dQkZ X-Proofpoint-GUID: 91-uvh5JY-SRRCM4OE5_Vua_DkZ2dQkZ X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.254,Aquarius:18.0.957,Hydra:6.0.591,FMLib:17.11.176.26 definitions=2023-06-29_10,2023-06-27_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 impostorscore=0 lowpriorityscore=0 clxscore=1011 bulkscore=0 suspectscore=0 mlxlogscore=999 malwarescore=0 priorityscore=1501 spamscore=0 mlxscore=0 adultscore=0 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2305260000 definitions=main-2306300029 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, This is just a gentle reminder, If any other information is needed. Tarun Sahu writes: > memory_group_register_static takes maximum number of pages as the argument > while dev_dax_kmem_probe passes total_len (in bytes) as the argument. > > IIUC, I don't see any crash/panic impact as such. As, > memory_group_register_static just set the max_pages limit which is used in > auto_movable_zone_for_pfn to determine the zone. > > which might cause these condition to behave differently, > > This will be true always so jump will happen to kernel_zone > ... > if (!auto_movable_can_online_movable(NUMA_NO_NODE, group, nr_pages)) > goto kernel_zone; > > ... > kernel_zone: > return default_kernel_zone_for_pfn(nid, pfn, nr_pages); > > Here, In below, zone_intersects compare range will be larger as nr_pages > will be higher (derived from total_len passed in dev_dax_kmem_probe). > > ... > static struct zone *default_kernel_zone_for_pfn(int nid, unsigned long start_pfn, > unsigned long nr_pages) > { > struct pglist_data *pgdat = NODE_DATA(nid); > int zid; > > for (zid = 0; zid < ZONE_NORMAL; zid++) { > struct zone *zone = &pgdat->node_zones[zid]; > > if (zone_intersects(zone, start_pfn, nr_pages)) > return zone; > } > > return &pgdat->node_zones[ZONE_NORMAL]; > } > > Incorrect zone will be returned here, which in later time might cause bigger > problem. > > Fixes: eedf634aac3b ("dax/kmem: use a single static memory group for a single probed unit") > Signed-off-by: Tarun Sahu > Reviewed-by: Vishal Verma > --- > V3<-V2 > 1. Removed skip characters. > > V2<-V1 > 1. Added more details to commit message > > > drivers/dax/kmem.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/dax/kmem.c b/drivers/dax/kmem.c > index 7b36db6f1cbd..898ca9505754 100644 > --- a/drivers/dax/kmem.c > +++ b/drivers/dax/kmem.c > @@ -99,7 +99,7 @@ static int dev_dax_kmem_probe(struct dev_dax *dev_dax) > if (!data->res_name) > goto err_res_name; > > - rc = memory_group_register_static(numa_node, total_len); > + rc = memory_group_register_static(numa_node, PFN_UP(total_len)); > if (rc < 0) > goto err_reg_mgid; > data->mgid = rc; > -- > 2.31.1 ~Tarun