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=-3.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, T_DKIMWL_WL_HIGH,T_DKIMWL_WL_MED,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 EB823FC6121 for ; Mon, 30 Jul 2018 18:01:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6952A208A1 for ; Mon, 30 Jul 2018 18:01:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=fb.com header.i=@fb.com header.b="Zc+blTtw"; dkim=pass (1024-bit key) header.d=fb.onmicrosoft.com header.i=@fb.onmicrosoft.com header.b="WUl7pWTa" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6952A208A1 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=fb.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732024AbeG3TiD (ORCPT ); Mon, 30 Jul 2018 15:38:03 -0400 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:56232 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728666AbeG3TiD (ORCPT ); Mon, 30 Jul 2018 15:38:03 -0400 Received: from pps.filterd (m0109334.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w6UHoupf014230; Mon, 30 Jul 2018 11:01:38 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-type; s=facebook; bh=U3IAqHuTQI5+fGwBjPHzcpkTcIvEn3WUFGPMfJBQWoY=; b=Zc+blTtwIAB0+Dv3QcOYzni3BSOW2ON3h3xV+cZo8aYAPbd5PHRH0R1MHExdy8emw1te mJ1Se4Fv0VGrWxAAIg2914g7n8ydelqZLj7/Sy9zbh2LQXJtwHCsZxyBK/hBWZx2CiGl mXMVR4MNZmABP9Q0raCrDJrJ4/vMt81dZqI= Received: from maileast.thefacebook.com ([199.201.65.23]) by mx0a-00082601.pphosted.com with ESMTP id 2kj57p0fjb-1 (version=TLSv1 cipher=ECDHE-RSA-AES256-SHA bits=256 verify=NOT); Mon, 30 Jul 2018 11:01:38 -0700 Received: from NAM01-BN3-obe.outbound.protection.outlook.com (192.168.183.28) by o365-in.thefacebook.com (192.168.177.33) with Microsoft SMTP Server (TLS) id 14.3.361.1; Mon, 30 Jul 2018 14:01:35 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.onmicrosoft.com; s=selector1-fb-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=U3IAqHuTQI5+fGwBjPHzcpkTcIvEn3WUFGPMfJBQWoY=; b=WUl7pWTa5r8TCrsLyLwpl8uDC6y7rQRy838H+06bVMk2xkAlGRECYzxMfVf12qwkF64IFQqSv+JnedMQTXaLV4L++Sj/wgyj7xntP6sgOjTE73aPMV0wyc8agULVuZf2cLOjXz2Ib5ErrR1QS3BFEQv/6RsX8+YgHM+2Oek+h98= Received: from castle.thefacebook.com (2620:10d:c090:200::6:484b) by SN1PR15MB0175.namprd15.prod.outlook.com (2a01:111:e400:58cf::14) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.995.21; Mon, 30 Jul 2018 18:01:27 +0000 From: Roman Gushchin To: CC: Michal Hocko , Johannes Weiner , David Rientjes , Tetsuo Handa , Tejun Heo , , , Roman Gushchin , Vladimir Davydov , Michal Hocko , Andrew Morton Subject: [PATCH 2/3] mm, oom: refactor oom_kill_process() Date: Mon, 30 Jul 2018 11:00:59 -0700 Message-ID: <20180730180100.25079-3-guro@fb.com> X-Mailer: git-send-email 2.14.4 In-Reply-To: <20180730180100.25079-1-guro@fb.com> References: <20180730180100.25079-1-guro@fb.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [2620:10d:c090:200::6:484b] X-ClientProxiedBy: MWHPR15CA0060.namprd15.prod.outlook.com (2603:10b6:301:4c::22) To SN1PR15MB0175.namprd15.prod.outlook.com (2a01:111:e400:58cf::14) X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: 3a521c10-fc15-4dc1-9807-08d5f64679de X-Microsoft-Antispam: BCL:0;PCL:0;RULEID:(7020095)(4652040)(8989117)(5600074)(711020)(4534165)(4627221)(201703031133081)(201702281549075)(8990107)(2017052603328)(7153060)(7193020);SRVR:SN1PR15MB0175; X-Microsoft-Exchange-Diagnostics: 1;SN1PR15MB0175;3:jhpNDoFxuGd2IoyjH20yxjr41KXDy3SpfgItPY71HpQjFhObS0Zzl5WMMFCkWR8T+RxEkOWFohEcvi/YSlckHrFHrBNVS+xaLbOnF2etN+oA3lgxyaimiGKHIO0j78HhW0HSBOD/aY+j/cN0m/gIkfdosaLtse4+AINvyyhTkWapidIJQKZQtj3JtQouW3b+h1+6sNmUb9Gd+vTEvSj3AxwyTxtjyiPgKLfFAVb9QzXhEbPbR5rP2T9/nQ6xxqUM;25:yPfb8+huXZUytdDHzE4zYsvvENAVs75vI7t9DPygbbRpwrGRi0eirP2QOuPjlDMG/fuEqupAE9eai2XUSnSo5qEND5FJLaG0xiyDt131qch/VjTWgMi7zURoowGxmDswUsCHAryIu09PjK+ucp1Jg8poA3bFNUqnnha0JkXQgIgjEGFIp9Kh4oi4uMGL2WTxNZuh9fJBPmQoNXvXzMSnlnQFDLtlafBBNI7dgW0pgTAnyitmt7QkugedOTWl9VTYQQyxbEOA4OGJxnRp9CDdsF8zxI8DLAkXxbpe9D3D3/no6ZxioGJLeftGRqbEFzoT7DWVmzv/AewfbdQwk1UFxw==;31:l+WyYchJoSbY/e20qu706z5WvrFLEqf9oInKcp8UuDDtXrS9+DQ7DD8/uor8/HtA6xi7mxqHtCBXyy1qgc91o38Qz+GxmKgJnb6X+eqi2FEWZcGBBl0BRFLdFS60ejA2APcZT9c25CnABB5+aOKowrI5VD3PkREr0gsSnRwgREUf0n/aaUN7J2M2NWeLVTQZqSdXKThFeCOl3EHP3zHaDEs1q+VgIH0w11Gjhro68Vc= X-MS-TrafficTypeDiagnostic: SN1PR15MB0175: X-Microsoft-Exchange-Diagnostics: 1;SN1PR15MB0175;20: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 X-Microsoft-Antispam-PRVS: X-Exchange-Antispam-Report-Test: UriScan:(274141268393343)(85827821059158)(67672495146484)(211936372134217)(42068640409301)(153496737603132); X-MS-Exchange-SenderADCheck: 1 X-Exchange-Antispam-Report-CFA-Test: BCL:0;PCL:0;RULEID:(8211001083)(6040522)(2401047)(5005006)(8121501046)(3231311)(11241501184)(944501410)(52105095)(93006095)(93001095)(10201501046)(3002001)(149027)(150027)(6041310)(20161123558120)(20161123562045)(20161123560045)(201703131423095)(201702281528075)(20161123555045)(201703061421075)(201703061406153)(20161123564045)(6072148)(201708071742011)(7699016);SRVR:SN1PR15MB0175;BCL:0;PCL:0;RULEID:;SRVR:SN1PR15MB0175; X-Microsoft-Exchange-Diagnostics: 1;SN1PR15MB0175;4:JYaptTCExKK1T1+XGXN7b+b2CT+TYsY4WBpkaUnuwi8crFmr8Yr8n4TDkg8+FcGhQ1H5icnrSFj4aXBRH89hGCmx7qXd5hz+ouroTcCvKTAtSLxv7t9mA/do/P9WmVV7eNdkAfkXJqIoEW+iPnZSij2brYudGBYWhYfSIDqmgC32i6c7A8qXjHKX0+NUiLD0Oqwj6xai/JUuU+EVTyqKTJsHqLiHF4y0Isu6VMUi5sVznCn9ksYQAs7vyRRIL4WXbkfhJBIXJ8nL0XJnXgB0voDMKOqSo4EOihzWvBP4nWCpPdtJZqfqffAZ0WGlkjZN0VPffreAlubWzb6S4bVFl+Kw57muxlhicLX5c7Gt2ue2YaaA8dT+U5vejTi7LQi2WUO4Q2cDqGN/nH33+RvoPBmvHRyvdYmGyI1vqczkQxo8kyKGUCcZhwT+AOyimmugABUjzPooJEocfYkX483LUoZehoSNe7Uwya+jur7m+Ko= X-Forefront-PRVS: 0749DC2CE6 X-Forefront-Antispam-Report: SFV:NSPM;SFS:(10019020)(346002)(396003)(39860400002)(376002)(366004)(136003)(189003)(199004)(36756003)(6116002)(8676002)(6486002)(16526019)(6506007)(386003)(186003)(1076002)(86362001)(69596002)(76176011)(52116002)(51416003)(52396003)(81156014)(106356001)(966005)(2351001)(105586002)(97736004)(8936002)(81166006)(305945005)(7736002)(53936002)(6666003)(39060400002)(50226002)(25786009)(53416004)(478600001)(6512007)(6306002)(7416002)(5660300001)(2906002)(6916009)(14444005)(54906003)(2361001)(16586007)(316002)(11346002)(446003)(48376002)(50466002)(47776003)(476003)(4326008)(46003)(68736007)(2616005)(486006)(42262002);DIR:OUT;SFP:1102;SCL:1;SRVR:SN1PR15MB0175;H:castle.thefacebook.com;FPR:;SPF:None;LANG:en;PTR:InfoNoRecords;MX:1;A:1; Received-SPF: None (protection.outlook.com: fb.com does not designate permitted sender hosts) X-Microsoft-Exchange-Diagnostics: =?us-ascii?Q?1;SN1PR15MB0175;23:mCU3/R42/l/IAvx5XrFX/h2rLO466sG7zxKa+CEAn?= =?us-ascii?Q?zF2GX9QzPFebBFk+EjiCLQ0m4nvtugk9m2EI+p3s3AAkiXUKqcfdpRvIxvvS?= =?us-ascii?Q?84oxeZkj9usaKn29cu06EMjDazGGHUgQ62hA1YiyG0qt6zcFo4pPCGcumbqz?= =?us-ascii?Q?J6PtPyz1gtDqI7lBs7+vLBMV1h/j6dQQ3AwdMoRvmJVKmqKMtaX04t78jYK6?= =?us-ascii?Q?Hz9sMQ7ggL6vXsyNby0edr0Jrz4ZVnztIrbb+NfXybksXYD5TRyRNKd/ZPZn?= =?us-ascii?Q?aY6ZWYOAMXlifwhqwJQ9T4IgcjfDaT4lIjFaLE9yZ2e7nz2zzZWA63khTNiF?= =?us-ascii?Q?MvpCh7JOU1/eH0k8y62e77h8mgKgXk428NKfEFwKYKE/kaQFqgLx3WuS0TOl?= =?us-ascii?Q?+O++mG1Yu7xhRyUa4dmgSib3P4rWuW9e8vGlctI/rZTpcXWRHDlBYkJ58f4/?= =?us-ascii?Q?V955qNOD6Mgd7UQcbr0Lbr0G6I/BNnbSoACZSKUPAeZuoZhAWYs2FwCevE2W?= =?us-ascii?Q?Wev73i7jvR3pXpEgsu3za2gtOIPre4ci0tHZXpLQ4CbTmCqOFak7N2Htig1K?= =?us-ascii?Q?lo/rlocHwSt9a2KFaHqOkMw2FgV3o/f/bORaTl3Ll3S7D4pE+8xto/7XmzUh?= =?us-ascii?Q?3CtlbQ/MtejddtVIWRw6aSor9TYqLc+nv9eKTqK0/hcuNW9y1wbEiC1kjxGQ?= =?us-ascii?Q?aSBXRAwfDK5PAXLIPkeTIp8vG9P6qoNq+42g8XYpdDLKHb/j4YX8oREMoj16?= =?us-ascii?Q?IzkUoIQMSS1TuxDtBsDnqtaHovqu2A/aPxXtqako/WQrRf2KMHJFBU7wJ5Ty?= =?us-ascii?Q?udcbJny0ByOZ2YuFXP/ozAK3hFnj6TOl85Ue0srs/WDXG/2p7Yvn9m6o15R8?= =?us-ascii?Q?hrUmd8xIFjXZC2F46xP0t1k/N2uqqW+o+kPsFV9tjQ279RFpySwg112bH5Ce?= =?us-ascii?Q?4WM3zwQFLyO+kDE21AAKdIjiLL4AKuqaSzYCNO6MGKHCCG6+np0Xq+BpbBQQ?= =?us-ascii?Q?fjlEZ2njwSdn3dcQD03Zxkz2B+7kPnTeE9gKpv+wYodKabqkrzggd4PVZME5?= =?us-ascii?Q?VhBKRekx6sn0fJtS/5sfa1Qcx07upZpfs36hxbj9sGjYUdP/Bu1+QgPh54Qe?= =?us-ascii?Q?yI/lOyqCEconOedRxOAKkagtOGFhvhid7bC3u3XkDkHCHYv7+8eVNcwjTd5h?= =?us-ascii?Q?Hqadpm+K89WyqYxXkuh+WlebssKhUXMNDmRTKrNwGPphCKTHaQ+bhm0X8kIk?= =?us-ascii?Q?4eSewA7MfgzHP3xNZU79TmZ1kTmAa+c8EA91tFIQ9Ayi9B0Es7yJQq66JtyX?= =?us-ascii?Q?/dZoigJCmD8CcJ97MOuIozAsaAgXyflFsGCT4Jx7q7MXnZ5AbMVkzDGg42mr?= =?us-ascii?Q?OznohM6LqTDsru0p5qHpcpeQNg=3D?= X-Microsoft-Antispam-Message-Info: rFufKv6swHrhYJ3IgN63qj/KEttKENqaty8CM/LrXsgK7vlQB+TKH2a5LWDX27SNUY+wDmec7Pw6qK0z67KfDspetqSinxc4hF/B6s+oD8yGnwkcmIvKiJlI+7FIy8sJqtyGSJXRw6GHobmtxU+MIZBzrJMrCX7KrZJinMJvHkdrTzY3D+HVaiJBDi+pE6F4lNRcopYGoHWP9Heowuq3uSeKVa509A0pRH1D3qrlfvZluYk9ctp83l9Jfi57kbTRZ2vaPKfL6tHjObPmRtuU9mDK3kMNWTbFZ+qj677lmOxvX1zi3tVxctQqvsIweeE65QnStLpiTDapv6wvU8V4JtrtmeyXgNC2Hohq7WJEbho= X-Microsoft-Exchange-Diagnostics: 1;SN1PR15MB0175;6:HNaDsjIX7o9hWPXQ2InWRK4seMVxBuKPlJSXxT/hDYPR85NEC/XxO01aNv1rw871nnaFXF8GDdO+Y5DE5SZtLiLEzNL9FpVzvlCNkChnEVNGqlWSEtgKTD3Y4fv7QVov95BcwpwOPrcSth+iwtixonGBZzrFGnWJ7ru8t2W+T5ZdzrL31OrM7gdZl4xs8rD4d7w5g5id3SY7fWaHqWqzOZ/no6tJFPpzHf0AZsVoHVTHwgAfjQzRW2wX8K1G0LcVvSuciwKXxwh1xQlP1x7F9aubJP6qD+Rdsw9imcqkgWsZzieLRkNLgSTwWtt/e/NjYK+iHuet0iRiz9XPW3p1rl4X/bZafxOnnmLzYmu1fvStNoA9EWaUkUByGjBSjvwDu3KoXtPEs6DDVRAGtRILrDnMMhadjzR7KAoOgNGTfZMN8uk+KqrJalIhqpYZyE6zWyraBbEmyXVfqimRsb1tLw==;5:7mGK7oLAmeFvuBM/u+exkn4hwpMe08VahAmjlrCLuv+A5pY9u4impWErvYRP37jNAZ9XGBPBwWfVo6Rn9K52IxV3DsW1EwnXYFAZnQTj+I3ehWP7bK39jIMDd1pAMs67IG6DvdvlO2GEJOola5IN2wXkvpyDD6CDbLtoARmHugE=;7:FMmb1PaIhh7bczH/01hrYcPChk1s2ooa42Z1AdB1lLMZ8zT4i6fwMZXI+IQh9RLekoa1yRfjbiArIIA87S4QZiBLqFFtipzXnfMVxQ5oa0CpjGH/DUXHyMEKJ2GOCqUcQcFrGd2CTjpunEyUSX7GsOLOouLcmrylDQAaybkPSQqTQHb1TNz2SG5BDVCb6MZP7aXoxo6NhGlEBgZP119HPTacUOGCY6Kfbu0JRhF96lAuRSsOfZeWI9c6eIZdHvK/ SpamDiagnosticOutput: 1:99 SpamDiagnosticMetadata: NSPM X-Microsoft-Exchange-Diagnostics: 1;SN1PR15MB0175;20:VMhAl2E0iIj9Dw+dDdjB//j9etbi6PAhdE4Jr/wc6nd1nAmNpzx2QnVIl+x+E+KBF/zmOhXnkr0VgcUtqci7dXXDT+v+4mZqMsseiMaoFmAqKVKsAQyh0ChLUePNTaoFfTqCuuaFdWNyz52q+2SrhqPOIb7yzKqXUa29fL2hN64= X-MS-Exchange-CrossTenant-OriginalArrivalTime: 30 Jul 2018 18:01:27.9244 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 3a521c10-fc15-4dc1-9807-08d5f64679de X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 8ae927fe-1255-47a7-a2af-5f3a069daaa2 X-MS-Exchange-Transport-CrossTenantHeadersStamped: SN1PR15MB0175 X-OriginatorOrg: fb.com X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-07-30_08:,, signatures=0 X-Proofpoint-Spam-Reason: safe X-FB-Internal: Safe Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org oom_kill_process() consists of two logical parts: the first one is responsible for considering task's children as a potential victim and printing the debug information. The second half is responsible for sending SIGKILL to all tasks sharing the mm struct with the given victim. This commit splits oom_kill_process() with an intention to re-use the the second half: __oom_kill_process(). The cgroup-aware OOM killer will kill multiple tasks belonging to the victim cgroup. We don't need to print the debug information for the each task, as well as play with task selection (considering task's children), so we can't use the existing oom_kill_process(). Link: http://lkml.kernel.org/r/20171130152824.1591-2-guro@fb.com Signed-off-by: Roman Gushchin Acked-by: Michal Hocko Acked-by: Johannes Weiner Acked-by: David Rientjes Cc: Vladimir Davydov Cc: Tetsuo Handa Cc: David Rientjes Cc: Tejun Heo Cc: Michal Hocko Signed-off-by: Andrew Morton --- mm/oom_kill.c | 123 +++++++++++++++++++++++++++++++--------------------------- 1 file changed, 65 insertions(+), 58 deletions(-) diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 84081e77bc51..8bded6b3205b 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -835,68 +835,12 @@ static bool task_will_free_mem(struct task_struct *task) return ret; } -static void oom_kill_process(struct oom_control *oc, const char *message) +static void __oom_kill_process(struct task_struct *victim) { - struct task_struct *p = oc->chosen; - unsigned int points = oc->chosen_points; - struct task_struct *victim = p; - struct task_struct *child; - struct task_struct *t; + struct task_struct *p; struct mm_struct *mm; - unsigned int victim_points = 0; - static DEFINE_RATELIMIT_STATE(oom_rs, DEFAULT_RATELIMIT_INTERVAL, - DEFAULT_RATELIMIT_BURST); bool can_oom_reap = true; - /* - * If the task is already exiting, don't alarm the sysadmin or kill - * its children or threads, just give it access to memory reserves - * so it can die quickly - */ - task_lock(p); - if (task_will_free_mem(p)) { - mark_oom_victim(p); - wake_oom_reaper(p); - task_unlock(p); - put_task_struct(p); - return; - } - task_unlock(p); - - if (__ratelimit(&oom_rs)) - dump_header(oc, p); - - pr_err("%s: Kill process %d (%s) score %u or sacrifice child\n", - message, task_pid_nr(p), p->comm, points); - - /* - * If any of p's children has a different mm and is eligible for kill, - * the one with the highest oom_badness() score is sacrificed for its - * parent. This attempts to lose the minimal amount of work done while - * still freeing memory. - */ - read_lock(&tasklist_lock); - for_each_thread(p, t) { - list_for_each_entry(child, &t->children, sibling) { - unsigned int child_points; - - if (process_shares_mm(child, p->mm)) - continue; - /* - * oom_badness() returns 0 if the thread is unkillable - */ - child_points = oom_badness(child, - oc->memcg, oc->nodemask, oc->totalpages); - if (child_points > victim_points) { - put_task_struct(victim); - victim = child; - victim_points = child_points; - get_task_struct(victim); - } - } - } - read_unlock(&tasklist_lock); - p = find_lock_task_mm(victim); if (!p) { put_task_struct(victim); @@ -970,6 +914,69 @@ static void oom_kill_process(struct oom_control *oc, const char *message) } #undef K +static void oom_kill_process(struct oom_control *oc, const char *message) +{ + struct task_struct *p = oc->chosen; + unsigned int points = oc->chosen_points; + struct task_struct *victim = p; + struct task_struct *child; + struct task_struct *t; + unsigned int victim_points = 0; + static DEFINE_RATELIMIT_STATE(oom_rs, DEFAULT_RATELIMIT_INTERVAL, + DEFAULT_RATELIMIT_BURST); + + /* + * If the task is already exiting, don't alarm the sysadmin or kill + * its children or threads, just give it access to memory reserves + * so it can die quickly + */ + task_lock(p); + if (task_will_free_mem(p)) { + mark_oom_victim(p); + wake_oom_reaper(p); + task_unlock(p); + put_task_struct(p); + return; + } + task_unlock(p); + + if (__ratelimit(&oom_rs)) + dump_header(oc, p); + + pr_err("%s: Kill process %d (%s) score %u or sacrifice child\n", + message, task_pid_nr(p), p->comm, points); + + /* + * If any of p's children has a different mm and is eligible for kill, + * the one with the highest oom_badness() score is sacrificed for its + * parent. This attempts to lose the minimal amount of work done while + * still freeing memory. + */ + read_lock(&tasklist_lock); + for_each_thread(p, t) { + list_for_each_entry(child, &t->children, sibling) { + unsigned int child_points; + + if (process_shares_mm(child, p->mm)) + continue; + /* + * oom_badness() returns 0 if the thread is unkillable + */ + child_points = oom_badness(child, + oc->memcg, oc->nodemask, oc->totalpages); + if (child_points > victim_points) { + put_task_struct(victim); + victim = child; + victim_points = child_points; + get_task_struct(victim); + } + } + } + read_unlock(&tasklist_lock); + + __oom_kill_process(victim); +} + /* * Determines whether the kernel must panic because of the panic_on_oom sysctl. */ -- 2.14.4