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=-6.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 857EDC433EF for ; Wed, 8 Sep 2021 08:02:05 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (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 3EC2760F5E for ; Wed, 8 Sep 2021 08:02:05 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 3EC2760F5E Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=amazon.co.uk Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=lists.xenproject.org Received: from list by lists.xenproject.org with outflank-mailman.181564.328721 (Exim 4.92) (envelope-from ) id 1mNsWg-0001Se-Ew; Wed, 08 Sep 2021 08:01:46 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 181564.328721; Wed, 08 Sep 2021 08:01:46 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1mNsWg-0001SX-Bq; Wed, 08 Sep 2021 08:01:46 +0000 Received: by outflank-mailman (input) for mailman id 181564; Wed, 08 Sep 2021 08:01:44 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1mNsWe-0001SR-DO for xen-devel@lists.xenproject.org; Wed, 08 Sep 2021 08:01:44 +0000 Received: from smtp-fw-9102.amazon.com (unknown [207.171.184.29]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id 011f09b2-107b-11ec-b147-12813bfff9fa; Wed, 08 Sep 2021 08:01:43 +0000 (UTC) Received: from pdx4-co-svc-p1-lb2-vlan3.amazon.com (HELO email-inbound-relay-1a-e34f1ddc.us-east-1.amazon.com) ([10.25.36.214]) by smtp-border-fw-9102.sea19.amazon.com with ESMTP; 08 Sep 2021 08:01:36 +0000 Received: from EX13D37EUA002.ant.amazon.com (iad12-ws-svc-p26-lb9-vlan3.iad.amazon.com [10.40.163.38]) by email-inbound-relay-1a-e34f1ddc.us-east-1.amazon.com (Postfix) with ESMTPS id 14C1CA1A39; Wed, 8 Sep 2021 08:01:33 +0000 (UTC) Received: from EX13D24EUA001.ant.amazon.com (10.43.165.233) by EX13D37EUA002.ant.amazon.com (10.43.165.200) with Microsoft SMTP Server (TLS) id 15.0.1497.23; Wed, 8 Sep 2021 08:01:32 +0000 Received: from EX13D24EUA001.ant.amazon.com ([10.43.165.233]) by EX13D24EUA001.ant.amazon.com ([10.43.165.233]) with mapi id 15.00.1497.023; Wed, 8 Sep 2021 08:01:32 +0000 X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" X-Inumbo-ID: 011f09b2-107b-11ec-b147-12813bfff9fa DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.co.uk; i=@amazon.co.uk; q=dns/txt; s=amazon201209; t=1631088104; x=1662624104; h=from:to:cc:subject:date:message-id:references: in-reply-to:content-id:content-transfer-encoding: mime-version; bh=NNiwhOsw2/lA3gYN93p8XpwsNp5oh1ZqFV8csTQzejw=; b=mu1DWzIvAsz7313KTLrdbLv4lb6nRAS4ffnSYp8E6Zkp4IsRzaxeoyKP mLbtIIVlQrjKnPf6LHER497CvSoIYVm4DrP5l1XyILeHFN42RJsgtMQwk Y1ntYdr5qLeyUmkuqZfh4iIId6PbMiPXsqy1zJoMjEN1PYojPfi5C08iK 4=; X-IronPort-AV: E=Sophos;i="5.85,277,1624320000"; d="scan'208";a="158343262" From: "Ahmed, Daniele" To: Dario Faggioli , "julien@xen.org" , "xen-devel@lists.xenproject.org" CC: "sstabellini@kernel.org" , "Pohlack, Martin" , "Grall, Julien" , "Doebel, Bjoern" Subject: Re: NULL scheduler DoS Thread-Topic: NULL scheduler DoS Thread-Index: AQHXpIe8OXmLgpZp00yyIO6D9XnksA== Date: Wed, 8 Sep 2021 08:01:32 +0000 Message-ID: <562980DD-ABAB-4082-A565-2E07F71292E5@amazon.com> References: <8193a685-3ab1-9407-75f3-e335ea4406e4@xen.org> <6b5e28f427ccd89505a4448f2b9e5be992a08292.camel@suse.com> In-Reply-To: <6b5e28f427ccd89505a4448f2b9e5be992a08292.camel@suse.com> Accept-Language: en-US Content-Language: en-GB X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-messagesentrepresentingtype: 1 x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.43.166.178] Content-Type: text/plain; charset="utf-8" Content-ID: Content-Transfer-Encoding: base64 MIME-Version: 1.0 Precedence: Bulk SGksIHNvcnJ5IGZvciB0aGUgbGF0ZSByZXBseS4NCg0KSGVyZSBpcyB0aGUgZnVsbCBsb2cgZnJv bSB0aGUgc2VyaWFsIGNvbnNvbGU6IGh0dHBzOi8vcGFzdGViaW4uY29tL3Jhdy9nOUVGdGszeQ0K DQpUaGlzIHN0aWxsIGhhcHBlbnMgb24gdGhlIGN1cnJlbnQgdW5zdGFibGUgYXMgb2YgdG9kYXku DQoNClRoYW5rIHlvdQ0KRGFuaWVsZQ0KDQrvu79PbiAxMS8wOC8yMDIxLCAxMjowOSwgIkRhcmlv IEZhZ2dpb2xpIiA8ZGZhZ2dpb2xpQHN1c2UuY29tPiB3cm90ZToNCg0KICAgIE9uIE1vbiwgMjAy MS0wOC0wOSBhdCAyMTozOCArMDEwMCwgSnVsaWVuIEdyYWxsIHdyb3RlOg0KICAgID4gT24gMDkv MDgvMjAyMSAxODozNSwgSnVsaWVuIEdyYWxsIHdyb3RlOg0KICAgID4gPiANCiAgICA+ID4gVGhp cyBpbXBsaWVzIHRoYXQgYSBwQ1BVIG1heSB0ZW1wb3JhcmlseSBiZSBhc3NpZ25lZCB0byB0d28g dkNQVXMNCiAgICA+ID4gYW5kIHdlIA0KICAgID4gPiBleHBlY3QgdG8gYmUgZml4ZWQgdXAgYWZ0 ZXJ3YXJkcy4gSG93ZXZlciwgYSBkb21haW4gbWF5IGJlDQogICAgPiA+IGRlc3Ryb3llZCANCiAg ICA+ID4gYmVmb3JlIHRoaXMgaXMgaGFwcGVuaW5nLg0KICAgID4gPiANCiAgICA+ID4gU28gaXQg bG9va3MgbGlrZSB0aGF0IHVuaXRfZGVhc3NpZ24oKSBpcyBub3QgYWJsZSB0byBjb3BlIHdpdGgg dGhpcw0KICAgID4gPiBjYXNlLiBGcm9tIGEgYnJpZWYgbG9vaywgSSB0aGluayB3ZSBtYXkgd2Fu dCB0byBjaGVjayBpZiB0aGUgcENQVQ0KICAgID4gPiBpcyBpbiANCiAgICA+ID4gdGhlIHdhaXQg bGlzdC4gSWYgaXQgaXMsIHRoZW4gd2Ugc2hvdWxkIGJhaWwgb3V0Lg0KICAgID4gDQogICAgPiBB Y3R1YWxseSwgSSB3YXMgd3JvbmcuIEl0IGxvb2tzIGxpa2UgbnVsbF91bml0X3JlbW92ZSgpIGlz IGFscmVhZHkgDQogICAgPiBjaGVja2luZyB0aGlzIGNvbmRpdGlvbi4gQWxzbywgdGhlIHZDUFUg c2hvdWxkIGJlIG9mZmxpbmUgKGFuZCB0aGUNCiAgICA+IHVuaXQgDQogICAgPiBhcyB3ZWxsKSBi ZWNhdXNlIHRoZXkgaGF2ZW4ndCBjb21lIG9ubGluZSB5ZXQ6DQogICAgPiANCiAgICBUaGF0J3Mg d2hhdCBpcyBjdXJyZW50bHkgcHV6emxpbmcgbWUuDQoNCiAgICBJIG1lYW4sIHRoZSBjcmFzaCBo YXBwZW5zIGluIHVuaXRfZGVhc3NpZ24oKSwgY2FsbGVkIGJ5DQogICAgbnVsbF91bml0X3JlbW92 ZSgpLCBjYWxsZWQgYnkgc2NoZWRfZGVzdHJveV92Y3B1KCkuDQoNCiAgICBBbmQgSSBhZ3JlZSB0 aGF0IHRoZSB1bml0IHNob3VsZCBiZSBvZmZsaW5lLCBidXQgbnVsbF91bml0X3JlbW92ZSgpDQog ICAgY2FsbHMgdW5pdF9kZWFzc2lnbigpIG9ubHkgaWYgdGhlIHVuaXQgKmlzKiBvbmxpbmUsIHNv Li4uIFdoYXQncyBnb2luZw0KICAgIG9uPyA6LS8NCg0KICAgIFJlZ2FyZHMNCiAgICAtLSANCiAg ICBEYXJpbyBGYWdnaW9saSwgUGguRA0KICAgIGh0dHA6Ly9hYm91dC5tZS9kYXJpby5mYWdnaW9s aQ0KICAgIFZpcnR1YWxpemF0aW9uIFNvZnR3YXJlIEVuZ2luZWVyDQogICAgU1VTRSBMYWJzLCBT VVNFIGh0dHBzOi8vd3d3LnN1c2UuY29tLw0KICAgIC0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0t LS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0NCiAgICA8PFRoaXMgaGFw cGVucyBiZWNhdXNlIF9JXyBjaG9vc2UgaXQgdG8gaGFwcGVuIT4+IChSYWlzdGxpbiBNYWplcmUp DQoNCg==