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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 1CE32C10F29 for ; Tue, 17 Mar 2020 14:51:27 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id D29C6206EC for ; Tue, 17 Mar 2020 14:51:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D29C6206EC 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=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 8366D6B0006; Tue, 17 Mar 2020 10:51:26 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 7BFB26B0007; Tue, 17 Mar 2020 10:51:26 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 688396B0008; Tue, 17 Mar 2020 10:51:26 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0159.hostedemail.com [216.40.44.159]) by kanga.kvack.org (Postfix) with ESMTP id 51F146B0006 for ; Tue, 17 Mar 2020 10:51:26 -0400 (EDT) Received: from smtpin11.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 29FD1180AD804 for ; Tue, 17 Mar 2020 14:51:26 +0000 (UTC) X-FDA: 76605142572.11.hand59_63c8971538c58 X-HE-Tag: hand59_63c8971538c58 X-Filterd-Recvd-Size: 5671 Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) by imf02.hostedemail.com (Postfix) with ESMTP for ; Tue, 17 Mar 2020 14:51:25 +0000 (UTC) Received: from pps.filterd (m0098410.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 02HEod0k129445 for ; Tue, 17 Mar 2020 10:51:24 -0400 Received: from e06smtp03.uk.ibm.com (e06smtp03.uk.ibm.com [195.75.94.99]) by mx0a-001b2d01.pphosted.com with ESMTP id 2yrutm0q8e-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 17 Mar 2020 10:51:22 -0400 Received: from localhost by e06smtp03.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 17 Mar 2020 14:51:14 -0000 Received: from b06avi18878370.portsmouth.uk.ibm.com (9.149.26.194) by e06smtp03.uk.ibm.com (192.168.101.133) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Tue, 17 Mar 2020 14:51:09 -0000 Received: from d06av26.portsmouth.uk.ibm.com (d06av26.portsmouth.uk.ibm.com [9.149.105.62]) by b06avi18878370.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 02HEp8Pr44761490 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 17 Mar 2020 14:51:08 GMT Received: from d06av26.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id BAC5BAE059; Tue, 17 Mar 2020 14:51:08 +0000 (GMT) Received: from d06av26.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 8CDD5AE055; Tue, 17 Mar 2020 14:51:06 +0000 (GMT) Received: from linux.vnet.ibm.com (unknown [9.126.150.29]) by d06av26.portsmouth.uk.ibm.com (Postfix) with SMTP; Tue, 17 Mar 2020 14:51:06 +0000 (GMT) Date: Tue, 17 Mar 2020 20:21:05 +0530 From: Srikar Dronamraju To: Vlastimil Babka Cc: Andrew Morton , linux-mm@kvack.org, Mel Gorman , Michael Ellerman , Sachin Sant , Michal Hocko , Christopher Lameter , linuxppc-dev@lists.ozlabs.org, Joonsoo Kim , Kirill Tkhai , Bharata B Rao Subject: Re: [PATCH 2/4] mm/slub: Use mem_node to allocate a new slab Reply-To: Srikar Dronamraju References: <3381CD91-AB3D-4773-BA04-E7A072A63968@linux.vnet.ibm.com> <20200317131753.4074-1-srikar@linux.vnet.ibm.com> <20200317131753.4074-3-srikar@linux.vnet.ibm.com> <20200317134523.GB4334@linux.vnet.ibm.com> <3d9629d4-4a6d-d2b5-28b7-58af497671c7@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <3d9629d4-4a6d-d2b5-28b7-58af497671c7@suse.cz> User-Agent: Mutt/1.10.1 (2018-07-13) X-TM-AS-GCONF: 00 x-cbid: 20031714-0012-0000-0000-000003929C71 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 20031714-0013-0000-0000-000021CF7BB7 Message-Id: <20200317145105.GA27520@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.138,18.0.645 definitions=2020-03-17_05:2020-03-17,2020-03-17 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxscore=0 malwarescore=0 clxscore=1015 phishscore=0 mlxlogscore=999 bulkscore=0 lowpriorityscore=0 suspectscore=0 adultscore=0 spamscore=0 priorityscore=1501 impostorscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2003020000 definitions=main-2003170061 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: * Vlastimil Babka [2020-03-17 14:53:26]: > >> > > >> > Mitigate this by allocating the new slab from the node_numa_mem. > >> > >> Are you sure this is really needed and the other 3 patches are not enough for > >> the current SLUB code to work as needed? It seems you are changing the semantics > >> here... > >> > > > > The other 3 patches are not enough because we don't carry the searchnode > > when the actual alloc_pages_node gets called. > > > > With only the 3 patches, we see the above Panic, its signature is slightly > > different from what Sachin first reported and which I have carried in 1st > > patch. > > Ah, I see. So that's the missing pgdat after your series [1] right? Yes the pgdat would be missing after my cpuless, memoryless node patchset. However.. > > That sounds like an argument for Michal's suggestions that pgdats exist and have > correctly populated zonelists for all possible nodes. Only the first patch in this series would be affected by pgdat existing or not. Even if the pgdat existed, the NODE_DATA[nid]->node_present_pages would be 0. Right? So it would look at node_to_mem_node(). And since node 0 is cpuless it would return 0. If we pass this node 0 (which is memoryless/cpuless) to alloc_pages_node. Please note I am only setting node_numa_mem only for offline nodes. However we could change this to set for all offline and memoryless nodes. > node_to_mem_node() could be just a shortcut for the first zone's node in the > zonelist, so that fallback follows the topology. > > [1] > https://lore.kernel.org/linuxppc-dev/20200311110237.5731-1-srikar@linux.vnet.ibm.com/t/#m76e5b4c4084380b1d4b193d5aa0359b987f2290e > -- Thanks and Regards Srikar Dronamraju