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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D40CAC7EE2A for ; Tue, 6 Jun 2023 08:24:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232009AbjFFIYV (ORCPT ); Tue, 6 Jun 2023 04:24:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51998 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235523AbjFFIYU (ORCPT ); Tue, 6 Jun 2023 04:24:20 -0400 Received: from eu-smtp-delivery-151.mimecast.com (eu-smtp-delivery-151.mimecast.com [185.58.86.151]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 94BFD10F4 for ; Tue, 6 Jun 2023 01:24:00 -0700 (PDT) Received: from AcuMS.aculab.com (156.67.243.121 [156.67.243.121]) by relay.mimecast.com with ESMTP with both STARTTLS and AUTH (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id uk-mta-27-nSSzYmyDMbyDTK30Pb0fqg-1; Tue, 06 Jun 2023 09:23:54 +0100 X-MC-Unique: nSSzYmyDMbyDTK30Pb0fqg-1 Received: from AcuMS.Aculab.com (10.202.163.6) by AcuMS.aculab.com (10.202.163.6) with Microsoft SMTP Server (TLS) id 15.0.1497.48; Tue, 6 Jun 2023 09:23:52 +0100 Received: from AcuMS.Aculab.com ([::1]) by AcuMS.aculab.com ([::1]) with mapi id 15.00.1497.048; Tue, 6 Jun 2023 09:23:52 +0100 From: David Laight To: "'H. Peter Anvin'" , 'Thomas Gleixner' , Muhammad Usama Anjum , Jonathan Corbet , Ingo Molnar , "Borislav Petkov" , Dave Hansen , "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" , "open list:DOCUMENTATION" , open list , "Guilherme G. Piccoli" CC: Steven Noonan , "kernel@collabora.com" Subject: RE: Direct rdtsc call side-effect Thread-Topic: Direct rdtsc call side-effect Thread-Index: AQHZlHOrHGvpd378GUKTvqmuipgWK698BnPAgAA4NYCAACHzkP///FcAgAEVfSA= Date: Tue, 6 Jun 2023 08:23:52 +0000 Message-ID: References: <6719fb05-382c-8ec4-ccda-72798906a54b@collabora.com> <87mt1jeax1.ffs@tglx> <353732783fde46919fdcf698c326b7ed@AcuMS.aculab.com> <87jzwi55qo.ffs@tglx> <4ea6e82c-4761-e0c9-3e75-8ec39eecb30a@zytor.com> In-Reply-To: <4ea6e82c-4761-e0c9-3e75-8ec39eecb30a@zytor.com> Accept-Language: en-GB, en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.202.205.107] MIME-Version: 1.0 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: aculab.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: base64 Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org RnJvbTogSC4gUGV0ZXIgQW52aW4NCj4gU2VudDogMDUgSnVuZSAyMDIzIDE3OjMyDQouLi4NCj4g VGhlIFRTQyBpcyBjZXJ0YWlubHkgbm90IHBlcmZlY3Q7IHBhcnRseSBiZWNhdXNlLCBpcm9uaWNh bGx5IGVub3VnaCwgaXQNCj4gd2FzIGludHJvZHVjZWQganVzdCAqYmVmb3JlKiBvdXQgb2Ygb3Jk ZXIgYW5kIHBvd2VyIG1hbmFnZW1lbnQgZW50ZXJlZA0KPiB0aGUgeDg2IHdvcmxkLg0KDQpBbm90 aGVyIGlzc3VlIGlzIHRoYXQgdGhlIGNyeXN0YWwgdXNlZCBmb3IgdGhlIGNwdSBjbG9jayB3b24n dCBiZQ0KdGhhdCBhY2N1cmF0ZSAoaW4gdGVybXMgb2YgcHBtIGVycm9yIHJhdGUpLCBhbmQgd2ls bCBoYXZlIHNpZ25pZmljYW50DQp0ZW1wZXJhdHVyZSBkcmlmdC4NCk9UT0ggdGhlIGNyeXN0YWwg aW4gdGhlIHRyYWRpdGlvbmFsIHg4NiBtb3RoZXJib2FyZCAnY2xvY2snIGNoaXANCmlzIChtZWFu dCB0byBiZSkgZGVzaWduZWQgdG8gaGF2ZSBsb25nIHRlcm0gYWNjdXJhY3kuDQpXaGlsZSByZWFk aW5nIHRoZSBUU0MgaXMgYSBsb3QgZmFzdGVyIHRoZXJlIG91Z2h0IHRvIGhhdmUgYmVlbg0Kc29t ZSBraW5kIG9mIFBMTCB0byBjb250aW51b3VzbHkgYWRqdXN0IHRoZSBtZWFzdXJlZCBUU0MgZnJl cXVlbmN5DQp0byBrZWVwIHN5bmNocm9uaXNlZCB3aXRoIHRoZSB0aW1lciBjaGlwLg0KKEluc3Rl YWQga2VybmVscyBlbmQgdXAgd3JpdGluZyB0aGUgZHJpZnRlZCBUU0MgYmFzZWQgdGltZSBiYWNr IHRvDQp0aGUgdGltZXIgY2hpcCBkdXJpbmcgc2h1dGRvd24uKSANCg0KPiBJdCBpcyBubyBzZWNy ZXQgdGhhdCBpdCBoYXMgYmVlbiBzbG93IHRvIGNhdGNoIHVwLiBJdCB3YXMgZWFzeSB0byBwdXQg YQ0KPiBjb3VudGVyIGluOyBpdCBpcyBhICpsb3QqIGhhcmRlciB0byBtYWtlIGl0IHdvcmsgaW4g YWxsIHRoZSBwb3NzaWJsZQ0KPiBzY2VuYXJpb3MgaW4gdGhlIHBvd2VyLW1hbmFnZWQsIG91dC1v Zi1vcmRlciB3b3JsZC4NCg0KVGhhdCByYXRoZXIgZGVwZW5kcyBvbiB3aGF0IHlvdSBtZWFuIGJ5 ICd3b3JrJyA6LSkNCg0KPiBJdCBpcyBvbmUgb2YgbXkgcGVyc29uYWwgcGV0IHByb2plY3RzIGlu IHRoZSBhcmNoaXRlY3R1cmUgd29yayB0byBwdXNoDQo+IHRvIGdldCB0aGF0IGxhc3QgZGlzdGFu Y2U7IHdlIGFyZSBub3QgeWV0IHRoZXJlLg0KDQpGb3IgcGVyZm9ybWFuY2UgbWVhc3VyZW1lbnRz IHBvc3NpYmx5IHdoYXQgeW91IHdhbnQgaXMgYSBzaW1wbGUNCmNsb2NrIGNvdW50ZXIgd2hpY2gg aXMgZGVwZW5kZW50IG9uIGFuIGEgcmVnaXN0ZXIuDQpTbyBwcmV0dHkgbXVjaCB6ZXJvIG92ZXJo ZWFkIGJ1dCBpcyBndWFyYW50ZWVkIHRvIGhhcHBlbiBhZnRlcg0Kc29tZSBvdGhlciBpbnN0cnVj dGlvbiB3aXRob3V0IHJlYWxseSBhZmZlY3RpbmcgdGhlIHBpcGVsaW5lLg0KDQpJSVJDIHRoZSB4 ODYgcGVyZm9ybWFuY2UgY291bnRlcnMgYXJlbid0IGRlcGVuZGVudCBvbiBhbnl0aGluZw0Kc28g dGhleSB0ZW5kIHRvIGV4ZWN1dGUgbXVjaCBlYXJsaWVyIHRoYW4geW91IHdhbnQuDQpPVE9IIHJk dHNjIGlzIGxpa2VseSB0byBiZSBzeW5jaHJvbmlzaW5nIGFuZCBhZmZlY3Qgd2hhdCBmb2xsb3dz Lg0KSVNUUiB1c2luZyByZHRzYyB0byB3YWl0IGZvciBpbnN0cnVjdGlvbnMgdG8gY29tcGxldGUg YW5kIHRoZW4NCnRoZSBwZXJmb3JtYW5jZSBjbG9jayBjb3VudGVyIHRvIHNlZSBob3cgbG9uZyBp dCB0b29rLg0KDQoJRGF2aWQNCg0KLQ0KUmVnaXN0ZXJlZCBBZGRyZXNzIExha2VzaWRlLCBCcmFt bGV5IFJvYWQsIE1vdW50IEZhcm0sIE1pbHRvbiBLZXluZXMsIE1LMSAxUFQsIFVLDQpSZWdpc3Ry YXRpb24gTm86IDEzOTczODYgKFdhbGVzKQ0K