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 4EE2FC18E5B for ; Tue, 17 Mar 2020 16:05:57 +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 0DF4220724 for ; Tue, 17 Mar 2020 16:05:56 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0DF4220724 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 lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 48hdLm0NjRzDqkf for ; Wed, 18 Mar 2020 03:05:52 +1100 (AEDT) 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=none (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 48hbhn5jpvzDqg3 for ; Wed, 18 Mar 2020 01:51:21 +1100 (AEDT) Received: from pps.filterd (m0098414.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 02HEoYJu056966 for ; Tue, 17 Mar 2020 10:51:18 -0400 Received: from e06smtp03.uk.ibm.com (e06smtp03.uk.ibm.com [195.75.94.99]) by mx0b-001b2d01.pphosted.com with ESMTP id 2ytb3phr58-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 17 Mar 2020 10:51:17 -0400 Received: from localhost by e06smtp03.uk.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) 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 Subject: Re: [PATCH 2/4] mm/slub: Use mem_node to allocate a new slab 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 mlxlogscore=999 bulkscore=0 spamscore=0 adultscore=0 phishscore=0 clxscore=1015 malwarescore=0 impostorscore=0 lowpriorityscore=0 suspectscore=0 mlxscore=0 priorityscore=1501 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2003020000 definitions=main-2003170061 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: , Reply-To: Srikar Dronamraju Cc: Sachin Sant , Michal Hocko , linux-mm@kvack.org, Kirill Tkhai , Mel Gorman , Joonsoo Kim , Andrew Morton , Bharata B Rao , linuxppc-dev@lists.ozlabs.org, Christopher Lameter Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" * 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