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=-3.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 141C0C433E7 for ; Sat, 17 Oct 2020 01:16:13 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (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 95EFC2076D for ; Sat, 17 Oct 2020 01:16:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="NDbggE/f"; dkim=fail reason="signature verification failed" (2048-bit key) header.d=marvell.com header.i=@marvell.com header.b="CzEDcR62"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=marvell.onmicrosoft.com header.i=@marvell.onmicrosoft.com header.b="lrRo8v/V" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 95EFC2076D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=marvell.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:Content-ID:In-Reply-To:References: Message-ID:Date:Subject:To:From:Reply-To:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=tyAkc/2JShwYL98SwG9KRvFvuIPTpqb2GAy40yhMBFw=; b=NDbggE/fH/EsWlj33eVAc8wnj N6OmIu13YX4L3FLaECVo3fQh+QfA7fHO4IhMaj+ajyARfuyNhiQ6AOkaWnfLWXeq/ewtlz3k/ODfe 8hNzNW2Z5DbpA7zRuRvjx/0qV9aY9J/3VoxuCowAjcWtpvZ4ufnfuCM/S1q8K+3Y6xmtXai3zjAZv is2ntnWduw2Nc7oYJ7eDV9iz0+F5enrm+OHcHzi8A3922S4yNC2tewuiwrSuSZXZBaokYxGbyzZqv 7y8bvb5Bn1YWQYG9Esd/XrBXbBKa2NHquhHyqLtmy9FHy0SSH/RpcPaZ1qZFcuOuO7EwiSPoPc0qf WWaYAyNng==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kTani-0006cL-0F; Sat, 17 Oct 2020 01:14:26 +0000 Received: from mx0b-0016f401.pphosted.com ([67.231.156.173]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kTanf-0006bv-99 for linux-arm-kernel@lists.infradead.org; Sat, 17 Oct 2020 01:14:24 +0000 Received: from pps.filterd (m0045851.ppops.net [127.0.0.1]) by mx0b-0016f401.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 09H1BHxv016687; Fri, 16 Oct 2020 18:13:22 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=marvell.com; h=from : to : cc : subject : date : message-id : references : in-reply-to : content-type : content-id : content-transfer-encoding : mime-version; s=pfpt0220; bh=qxYRNYcBZHve6q7ipE5aq+bLghDuu6rqnpeeDfrN9fg=; b=CzEDcR62kEe2aZvIZKYTb3clvutZ9A/rzotv9PQ5j1NnbR4HKJFxDVEIvoDliidWezEg aDZ9MRJnfOsL7MKqa2eMeTFFryAzZMJBiRQmCV2mhxFHKPnfR1EaWDM6Z3P/1p831Kb+ 415qVz2qZas3b0m7FdyZ2PyLTfzM2uyD0DftMcX9/ZGtjX0ZxqP5bGQhmhJjPdCr2Iyo uhV5l+FVfwLO4WAnV2ALkpMXTSeSL0vF1CuRWrE9s1it5xKmlWKF32ovlSCgXuhLhFZ5 3XEA8pQ/QcFA+/qAu9FLzO8LmglctwJ5Voj40FmkAC3YfohUWlSUNVyAm8NCEWDKFfE5 dA== Received: from sc-exch03.marvell.com ([199.233.58.183]) by mx0b-0016f401.pphosted.com with ESMTP id 343cfjrst9-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-SHA384 bits=256 verify=NOT); Fri, 16 Oct 2020 18:13:21 -0700 Received: from SC-EXCH04.marvell.com (10.93.176.84) by SC-EXCH03.marvell.com (10.93.176.83) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Fri, 16 Oct 2020 18:13:19 -0700 Received: from SC-EXCH02.marvell.com (10.93.176.82) by SC-EXCH04.marvell.com (10.93.176.84) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Fri, 16 Oct 2020 18:13:19 -0700 Received: from NAM02-CY1-obe.outbound.protection.outlook.com (104.47.37.57) by SC-EXCH02.marvell.com (10.93.176.82) with Microsoft SMTP Server (TLS) id 15.0.1497.2 via Frontend Transport; Fri, 16 Oct 2020 18:13:19 -0700 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=b1C9L8GHKLutubi7eqGCI3uZYxCPLh6JbryXTpx18kjAx1LZt3B2BQhCq/snEVeRdw6rFLk4xdGhJJFghACRQv1UMKSvzbUsa6WkSsO7HEh/HRrbroPdfYnDR+39q8t57d5PAvZmOAD2yQdUZeDT5XQGK80+xc2y3RjwitJYpQO4/OP6itJg+XyBKcq5KLIxA+ToGR6GJjUMYHFTfisHggBHI37drcAiav5zZAtR+b3ehnbuxkpkeQxJz/TwKF+SlN/54Itkpoy3jYJs66OzN92ZpkIZcoW2XcMmgNidzTnioTTXlYMDp2sv+690bOWVaK6fZVHX7lFr8nWRvTRR8A== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=qxYRNYcBZHve6q7ipE5aq+bLghDuu6rqnpeeDfrN9fg=; b=Wdkrx1nGOMxgwkQ1uu4aR7mzjzxIc05l8E4gP1tBt2PZiJDArqVOfakEpeH3Sd2q/HDTzWFL2miwU/uAePi5h+/mtFotvAkgKC+YP79Kmra4jJ135ke+MBA1P3Q86d+8XKS3yjeaCU6PgvYCu/CpiollNf2Bh8ofbg82L2pb0JnVzb5fgPl6hPUip3vQq/Gc/iOdGTar3YpKk0h8qpe64kJ5oLiOoHxZIib7aMsN/prMtz3CbRUuxPFBvfMOfukyTHxncq9edrQfF9K3RODx7bQRFB//5S0/DNUSVMSMB5OowV0PwiOELDlJtmpzc883xGdC8faGL14YJAONm+tL9g== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=marvell.com; dmarc=pass action=none header.from=marvell.com; dkim=pass header.d=marvell.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=marvell.onmicrosoft.com; s=selector1-marvell-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=qxYRNYcBZHve6q7ipE5aq+bLghDuu6rqnpeeDfrN9fg=; b=lrRo8v/VUZYyVGSwvYK8fzmciBy7KA8OWvuEj9FRgWLhpxkniL/grxdKss2rdDWR+0AHPemC3qBpA3Aat1pacn/SFZm+BSRfFBy7kWgwsxk02ZLAk+SbeUHSBoNt8oODBLvxzjlKMfRvUCKLq/iNnkyUsaot0rHwD2Q4daRIego= Received: from MW2PR18MB2267.namprd18.prod.outlook.com (2603:10b6:907:3::11) by MWHPR1801MB1822.namprd18.prod.outlook.com (2603:10b6:301:6b::19) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.3455.23; Sat, 17 Oct 2020 01:13:18 +0000 Received: from MW2PR18MB2267.namprd18.prod.outlook.com ([fe80::69b0:73ce:7112:3b95]) by MW2PR18MB2267.namprd18.prod.outlook.com ([fe80::69b0:73ce:7112:3b95%7]) with mapi id 15.20.3455.031; Sat, 17 Oct 2020 01:13:18 +0000 From: Alex Belits To: "frederic@kernel.org" , "nitesh@redhat.com" Subject: Re: [EXT] Re: [PATCH v4 03/13] task_isolation: userspace hard isolation from kernel Thread-Topic: [EXT] Re: [PATCH v4 03/13] task_isolation: userspace hard isolation from kernel Thread-Index: AQHWYDdZDqoeqvfF50CzG3l43t/UoamDNPAAgATEYwCAAI5YAIABSVeAgAEHb4CAEKyCAA== Date: Sat, 17 Oct 2020 01:13:17 +0000 Message-ID: <98978b81e7eda04c256c3d837c36a032f5d475fb.camel@marvell.com> References: <04be044c1bcd76b7438b7563edc35383417f12c8.camel@marvell.com> <20201001135640.GA1748@lothringen> <7e54b3c5e0d4c91eb64f2dd1583dd687bc34757e.camel@marvell.com> <20201004231404.GA66364@lothringen> <20201006103541.GA31325@lothringen> In-Reply-To: <20201006103541.GA31325@lothringen> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: authentication-results: kernel.org; dkim=none (message not signed) header.d=none;kernel.org; dmarc=none action=none header.from=marvell.com; x-originating-ip: [173.228.7.197] x-ms-publictraffictype: Email x-ms-office365-filtering-correlation-id: c5676cdc-75ee-4b49-5fba-08d87239d4bd x-ms-traffictypediagnostic: MWHPR1801MB1822: x-ms-exchange-transport-forked: True x-microsoft-antispam-prvs: x-ms-oob-tlc-oobclassifiers: OLM:8882; x-ms-exchange-senderadcheck: 1 x-microsoft-antispam: BCL:0; x-microsoft-antispam-message-info: 3URA+X43WSV3Wb3OTUPp0tlhgi0d7Soi9DqIryds9a+p+VlnsELzCdogvbFyoM9WMq17Dgda5WcKzDSdA14TBP/RUFuusps37sdHCnGVXuWQGWoZlj2VzzC0hIS8A4HDUNHOMWHDrota90CobO0gUhFoUyBpz5x0Klh/KLoBErUX11vcMmBlIZlFzMmpiM4RkW+TLs2IRAA1JD5EyRNIxtVyRqW2oIYkVapk49UGDgknd1YQNgz80m35vmSeBA0WZsVBegLOblXBVwI75idbLLxYWBMWmb1GtyitGvY2sk/M7KKVgsZ3iam96bDi4YbXanVuajsK2ggNB77DLSPksw== x-forefront-antispam-report: CIP:255.255.255.255; CTRY:; LANG:en; SCL:1; SRV:; IPV:NLI; SFV:NSPM; H:MW2PR18MB2267.namprd18.prod.outlook.com; PTR:; CAT:NONE; SFS:(4636009)(366004)(396003)(346002)(136003)(39860400002)(376002)(53546011)(6506007)(66476007)(66556008)(186003)(2616005)(86362001)(6486002)(4326008)(76116006)(91956017)(6512007)(316002)(66946007)(7416002)(8936002)(71200400001)(66446008)(64756008)(5660300002)(54906003)(2906002)(478600001)(26005)(110136005)(8676002)(36756003); DIR:OUT; SFP:1101; x-ms-exchange-antispam-messagedata: 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 Content-ID: MIME-Version: 1.0 X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-AuthSource: MW2PR18MB2267.namprd18.prod.outlook.com X-MS-Exchange-CrossTenant-Network-Message-Id: c5676cdc-75ee-4b49-5fba-08d87239d4bd X-MS-Exchange-CrossTenant-originalarrivaltime: 17 Oct 2020 01:13:17.9698 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 70e1fb47-1155-421d-87fc-2e58f638b6e0 X-MS-Exchange-CrossTenant-mailboxtype: HOSTED X-MS-Exchange-CrossTenant-userprincipalname: oVD0YUawy/yBvoyLQiyqgE1dtT2WqDqqQl35zKi2H7vXvisuK6WUcXkC6ejckHHKX+fQIh6oQeRlmT54v/QlOQ== X-MS-Exchange-Transport-CrossTenantHeadersStamped: MWHPR1801MB1822 X-OriginatorOrg: marvell.com X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235, 18.0.687 definitions=2020-10-16_12:2020-10-16, 2020-10-16 signatures=0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201016_211423_392926_A83A3CAA X-CRM114-Status: GOOD ( 28.83 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "linux-arch@vger.kernel.org" , "peterz@infradead.org" , "linux-api@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "rostedt@goodmis.org" , "davem@davemloft.net" , "netdev@vger.kernel.org" , "catalin.marinas@arm.com" , Prasun Kapoor , "tglx@linutronix.de" , "will@kernel.org" , "mingo@kernel.org" , "linux-arm-kernel@lists.infradead.org" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, 2020-10-06 at 12:35 +0200, Frederic Weisbecker wrote: > On Mon, Oct 05, 2020 at 02:52:49PM -0400, Nitesh Narayan Lal wrote: > > On 10/4/20 7:14 PM, Frederic Weisbecker wrote: > > > On Sun, Oct 04, 2020 at 02:44:39PM +0000, Alex Belits wrote: > > > > > > > The idea behind this is that isolation breaking events are > > > > supposed to > > > > be known to the applications while applications run normally, > > > > and they > > > > should not require any analysis or human intervention to be > > > > handled. > > > Sure but you can use trace events for that. Just trace > > > interrupts, workqueues, > > > timers, syscalls, exceptions and scheduler events and you get all > > > the local > > > disturbance. You might want to tune a few filters but that's > > > pretty much it. > > formation, > > > you can trace the workqueue and timer queue events and just > > > filter those that > > > target your isolated CPUs. > > > > > > > I agree that we can do all those things with tracing. > > However, IMHO having a simplified logging mechanism to gather the > > source of > > violation may help in reducing the manual effort. > > > > Although, I am not sure how easy will it be to maintain such an > > interface > > over time. > > The thing is: tracing is your simplified logging mechanism here. You > can achieve > the same in userspace with _way_ less code, no race, and you can do > it in > bash. The idea is that this mechanism should be usable when no one is there to run things in bash, or no information about what might happen. It should be able to report rare events in production when users may not be able to reproduce them. -- Alex _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel