From owner-freebsd-current@freebsd.org Sat Apr 21 19:22:00 2018 Return-Path: Delivered-To: freebsd-current@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 86C13F8B36F for ; Sat, 21 Apr 2018 19:22:00 +0000 (UTC) (envelope-from rmacklem@uoguelph.ca) Received: from CAN01-TO1-obe.outbound.protection.outlook.com (mail-eopbgr670067.outbound.protection.outlook.com [40.107.67.67]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (Client CN "mail.protection.outlook.com", Issuer "Microsoft IT TLS CA 4" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 0F9D37E932 for ; Sat, 21 Apr 2018 19:21:59 +0000 (UTC) (envelope-from rmacklem@uoguelph.ca) Received: from YQBPR0101MB1042.CANPRD01.PROD.OUTLOOK.COM (52.132.66.153) by YQBPR0101MB0945.CANPRD01.PROD.OUTLOOK.COM (52.132.66.24) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id 15.20.696.12; Sat, 21 Apr 2018 19:21:58 +0000 Received: from YQBPR0101MB1042.CANPRD01.PROD.OUTLOOK.COM ([fe80::893c:efc2:d71f:945a]) by YQBPR0101MB1042.CANPRD01.PROD.OUTLOOK.COM ([fe80::893c:efc2:d71f:945a%13]) with mapi id 15.20.0696.015; Sat, 21 Apr 2018 19:21:58 +0000 From: Rick Macklem To: "freebsd-current@freebsd.org" CC: George Mitchell , Peter Subject: SCHED_ULE makes 256Mbyte i386 unusable Thread-Topic: SCHED_ULE makes 256Mbyte i386 unusable Thread-Index: AQHT2aRaIslt1yc1ckCslUza9Eao6A== Date: Sat, 21 Apr 2018 19:21:58 +0000 Message-ID: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-publictraffictype: Email x-microsoft-exchange-diagnostics: 1; YQBPR0101MB0945; 7:DP/1uJjD2f6ure9Ou20XP48a0hFUHRI/ZfzAA+n1jPZguD6bhKrk8IsGqvUndDGqsvSRv2zLTK36FY+xzRY3/bz+hwjOs2w02IHGdCGFBscRw1+cZfuY9NYQSuBbIwS+xp2wE5tTwZEqNK9vUYbfnZ/65NhQ5lZDShTdr8f2E3WYOTpRMOkU87+zpiwSNrBPU/zj8cqN0VFVzSmnPi6ZNEKCZwUmKVVrH1RspOEcQLDppuDxPNAuad5rNsvax9Ag x-ms-exchange-antispam-srfa-diagnostics: SOS; x-microsoft-antispam: UriScan:; BCL:0; PCL:0; RULEID:(7020095)(4652020)(8989080)(4534165)(4627221)(201703031133081)(201702281549075)(8990040)(5600026)(2017052603328)(7153060)(7193020); SRVR:YQBPR0101MB0945; x-ms-traffictypediagnostic: YQBPR0101MB0945: authentication-results: outbound.protection.outlook.com; spf=skipped (originating message); dkim=none (message not signed) header.d=none; dmarc=none action=none header.from=uoguelph.ca; x-microsoft-antispam-prvs: x-exchange-antispam-report-test: UriScan:(158342451672863); x-exchange-antispam-report-cfa-test: BCL:0; PCL:0; RULEID:(6040522)(2401047)(8121501046)(5005006)(3231232)(944501409)(52105095)(93006095)(93001095)(10201501046)(3002001)(6041310)(20161123564045)(20161123558120)(201703131423095)(201702281529075)(201702281528075)(20161123555045)(201703061421075)(201703061406153)(20161123562045)(20161123560045)(6072148)(201708071742011); SRVR:YQBPR0101MB0945; BCL:0; PCL:0; RULEID:; SRVR:YQBPR0101MB0945; x-forefront-prvs: 064903DDDC x-forefront-antispam-report: SFV:NSPM; SFS:(10009020)(376002)(396003)(366004)(346002)(39380400002)(39860400002)(786003)(5640700003)(476003)(2351001)(8676002)(74482002)(2906002)(5250100002)(8936002)(2501003)(86362001)(316002)(26005)(81166006)(6916009)(4326008)(25786009)(33656002)(6506007)(102836004)(2900100001)(74316002)(186003)(305945005)(3660700001)(55016002)(9686003)(54906003)(3280700002)(53936002)(6436002)(5660300001)(7696005)(478600001); DIR:OUT; SFP:1101; SCL:1; SRVR:YQBPR0101MB0945; H:YQBPR0101MB1042.CANPRD01.PROD.OUTLOOK.COM; FPR:; SPF:None; LANG:en; MLV:sfv; x-microsoft-antispam-message-info: ukD2wjylXQx+iKOkCs1NrKytFj4ON/IyUi9zcdyYMQ0mGpZsySgImL+gtde94NJcRxmV3YPdtNVD6jmnQ/+vEhkXHdYU4Govp7ncodTsd5uWDVDIZzVH3ZsLKo56aFgjDfMiRuE4hJcfSDta6VMoOdHGsOU2ZGsNCSGh+ClVTx+RrRqSkuGR3SVIgaxs3Cy4 spamdiagnosticoutput: 1:99 spamdiagnosticmetadata: NSPM Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-MS-Office365-Filtering-Correlation-Id: 7709c262-e907-4eec-b7a2-08d5a7bd26b5 X-OriginatorOrg: uoguelph.ca X-MS-Exchange-CrossTenant-Network-Message-Id: 7709c262-e907-4eec-b7a2-08d5a7bd26b5 X-MS-Exchange-CrossTenant-originalarrivaltime: 21 Apr 2018 19:21:58.1956 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: be62a12b-2cad-49a1-a5fa-85f4f3156a7d X-MS-Exchange-Transport-CrossTenantHeadersStamped: YQBPR0101MB0945 X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.25 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 21 Apr 2018 19:22:00 -0000 I decided to start a new thread on current related to SCHED_ULE, since I se= e more than just performance degradation and on a recent current kernel. (I cc'd a couple of the people discussing performance problems in freebsd-s= table recently under a subject line of "Re: kern.sched.quantum: Creepy, sadistic= scheduler". When testing a pNFS server on a single core i386 with 256Mbytes using a Dec= . 2017 current/head kernel, I would see about a 30% performance degradation (elaps= ed run time for a kernel build over NFSv4.1) when the server kernel was built = with options SCHED_ULE instead of options SCHED_4BSD Now, with a kernel from a couple of days ago, the options SCHED_ULE kernel becomes unusable shortly after starting testing. I have seen two variants of this: - Became essentially hung. All I could do was ping the machine from the net= work. - Reported "vm_thread_new: kstack allocation failed and then any attempt to do anything gets "No more processes". with the only difference being a kernel built with options SCHED_4BSD everything works and performs the same as the Dec 2017 kernel. I can try rolling back through the revisions, but it would be nice if someo= ne could suggest where to start, because it takes a couple of hours to build a kernel on this system. So, something has made things worse for a head/current kernel this winter, = rick