From:   "Luck, Tony" <tony.luck@intel.com>
To:     "Torvalds, Linus" <torvalds@linux-foundation.org>
CC:     Jakub Jelinek <jakub@redhat.com>,
        Segher Boessenkool <segher@kernel.crashing.org>,
        Peter Zijlstra <peterz@infradead.org>,
        "Nick Desaulniers" <ndesaulniers@google.com>,
        "Eranian, Stephane" <eranian@google.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "Chatre, Reinette" <reinette.chatre@intel.com>,
        "Yu, Fenghua" <fenghua.yu@intel.com>,
        "peternewman@google.com" <peternewman@google.com>,
        "james.morse@arm.com" <james.morse@arm.com>,
        "babu.moger@amd.com" <babu.moger@amd.com>,
        "ananth.narayan@amd.com" <ananth.narayan@amd.com>,
        "vschneid@redhat.com" <vschneid@redhat.com>,
        Nathan Chancellor <nathan@kernel.org>,
        clang-built-linux <llvm@lists.linux.dev>,
        Borislav Petkov <bp@alien8.de>,
        "H. Peter Anvin" <hpa@zytor.com>,
        "linux-toolchains@vger.kernel.org" <linux-toolchains@vger.kernel.org>
Subject: RE: [PATCH] x86/resctrl: avoid compiler optimization in
 __resctrl_sched_in
Thread-Topic: [PATCH] x86/resctrl: avoid compiler optimization in
 __resctrl_sched_in
Thread-Index: AQHZTiWcwVo9jaQOt0u1ztY/yRpe/a7tql4AgADNkgCAAL2tgIAAd3MAgAAhmACAAAL3gIAAA5lAgAACGICAAAGrIIAANPzQ
Date:   Wed, 8 Mar 2023 00:36:39 +0000
Message-ID: <SJ1PR11MB6083D732726BE2BF06DAC3CEFCB49@SJ1PR11MB6083.namprd11.prod.outlook.com>
References: <20230303231133.1486085-1-eranian@google.com>
 <20230306120106.GE1267364@hirez.programming.kicks-ass.net>
 <CAKwvOdnRvd5KK01awAyeyt5S36TPPW4_8Z6YL1r4gB-pBrHTbg@mail.gmail.com>
 <20230307113545.GB2017917@hirez.programming.kicks-ass.net>
 <20230307184315.GS25951@gate.crashing.org> <ZAeh8g0nr3IFRSVI@tucnak>
 <CAHk-=whOLcy=oz=gHyoSSEnqc3M-APKFKTtTvA_3wYYPV8L+oA@mail.gmail.com>
 <SJ1PR11MB6083CADB2B6E859915D456F7FCB79@SJ1PR11MB6083.namprd11.prod.outlook.com>
 <CAHk-=whzzd53rW5Uk0oK7bXVXS_X6sJiisnhrqaz+MkutO7qug@mail.gmail.com>
 <SJ1PR11MB60834C09C9F85D401C2EB0FBFCB79@SJ1PR11MB6083.namprd11.prod.outlook.com>
In-Reply-To: <SJ1PR11MB60834C09C9F85D401C2EB0FBFCB79@SJ1PR11MB6083.namprd11.prod.outlook.com>
Accept-Language: en-US
Content-Language: en-US
x-ms-exchange-antispam-messagedata-chunkcount: 1
x-ms-exchange-antispam-messagedata-0: =?utf-8?B?akZJaHoxRytPSTdXUExDMVNvNjYrcjd3S1VjeXpTcXZHOS8vOG5QT3RraGJM?=
 =?utf-8?B?UkgrdFlIQythQ0xxdDd0UFV4aFpzSloyTmN2b3BnQzhhdTFZMnlZbW82ajgx?=
 =?utf-8?B?MTZkK0xpKzZSMXpneFNweU50NUVQTU1wT21MNzBWR092REQvd09JVDB5Qi8v?=
 =?utf-8?B?dGVkcm1Zb2NkbXVEZEpCZ3RoNkJnR0xlQm82cHkrRktTZ2VhZEl6a0dXZzMv?=
 =?utf-8?B?UVd3YXhudzYwZjBOZ2M5SVNtRkduSG5LNmtrZ1JJYWIyVG9FY2xiYVFMNkIw?=
 =?utf-8?B?ejJEYzJnUXppTVNNS01XdFNnTnozdEJaZnY5Wk9SODZweTQyNG1OaVIrTVNY?=
 =?utf-8?B?QW1RNDRYeGlrSmFZRU1GaGozQmNaVWZrNk0velhyQUswdUwxWjVIZTdiTWNU?=
 =?utf-8?B?ZXRSZ1BTNXpsZnZ4WU14MTljKzE0SzB1ZmRYeGo4RzZ1eElrOEt3azc5eDFq?=
 =?utf-8?B?cFBwa01GZDBBVVFxNXpvM3E2My83KzZITDlNR2JrU2FBK1RpTXFBRlRYc0N0?=
 =?utf-8?B?ZURnc2dOcEJPM2VHc1p3YVR2VE5pL0tEaU56bmxwNHY2MWRFejBkN0dGL1Aw?=
 =?utf-8?B?WFl5RU85UURCamVXcnlvNk5Gazd1QlNhc1hFOGtDQWtXeG9ieW5sK3RsclNl?=
 =?utf-8?B?bmlmdHBYa3V6cUMxcUkyYWtkd0xOeWJDc1BMTFBSczNlendhbkMrVjlEQWpS?=
 =?utf-8?B?ejRSTFRTUHI1TXh5ZjQ3azRVMmNGRWdxOElyY2piZHNqdytRQWRQSVhVOVNC?=
 =?utf-8?B?bFpzYnRHQ3Fod3NKODgyNEhvWDhMUlRGdjRSdTI4YW9ualpBekhUTFdWTUl6?=
 =?utf-8?B?N3dTZWgyQ3BvSDdSRE9lYUVoNDdjcjJWVVQwQStjU2s1aHpMclJaUVAzMFBM?=
 =?utf-8?B?VExURmQzcTMwZGdPdkZsNmJXTk9BcHFzZW5ETDZ2bVFJZUQwNFpkdmtXMk5a?=
 =?utf-8?B?ZGoxVnFLYjRYclgwU254MUtBcjltZy85S21JcVV6ai9FTGZUWmh0SFFJVCtD?=
 =?utf-8?B?ZGdiZ2dJcHNOSVBZeGV1QWlLMW9PSDk3a2YvSnlONkI5NTBqOHE3eWVPOGtR?=
 =?utf-8?B?SlNBOW9QVkxjSjB0OWVzakxQeWF5N1RsWVdOa3hlWmMvN0M1VXkydy9Cb2tT?=
 =?utf-8?B?NEtmUDN6eWM4YmIzL1VVV1FRZXlNbCtmTEtQRk5NOGg2S1NXR3ZpRlprd0Rh?=
 =?utf-8?B?L1ZvZVNzTVJIL1BESEMyUGJ2UkFyZ3VrSmN4MjE2Q08xQ0RTSjRLNjZXZ3Zz?=
 =?utf-8?B?K283QzNtNDVHMWdPU2N2emtIR1ByV2IxbUlvWHJGQjluMmRRK2Y4Yjg0aXhm?=
 =?utf-8?B?d2ZjQVAvNEwxaHQvMkNhSkpNWFN2YmtCK21EMTczYzd0OTQ0KzMxTW92YVAx?=
 =?utf-8?B?SldwSTBvSkNERmJuVXRKbEhRVXBpV3FaWkh1RmlPM1ZXL2hDZ1c1V2JnR1VE?=
 =?utf-8?B?V1ZzWW5VdG5vYmFOaWVqWFRnOUx0dkdoUE5pYTVjNCtkYS9QUk1TUldZaEZ1?=
 =?utf-8?B?bzE1R1R5Rm9NbEk1dElQOFBNMyt3alEyS2JYZkUwM3ZEc2wxVU5Ja0Jic3NP?=
 =?utf-8?B?ZjdJaEp1L01YTFdJYjVxVk1nL2swMEFUN0RNcUFQcXQvMEdIUU1YVWd1YVVx?=
 =?utf-8?B?RkNkeGtuaEhLbFZTeXFzaGhDNnFDV0ZKWDNjeHJDVUtPanE5bjhEcEVHRnZm?=
 =?utf-8?B?RmUyMkFQcFNyNThRSFAybk0wVVpuNm1sdWVLMzdMTmwvQXBSOTJmRG9RYmtN?=
 =?utf-8?B?cXA3MjdrVFNYRTcxZExtckUwYXlDbm1tQlRmOWZETjIrY0h3U3lwRWwySFk1?=
 =?utf-8?B?OGJxN0tleVM3U0JPRnNMK3JmdlZ3b2xVcU5nSjk3QkV0K2ZvNnpBWkZoUmdP?=
 =?utf-8?B?Z0VhVVVBZ0xjR2F3cGlSdjc0ZjkwV1g0NmxiK1FMRHllL3paQkVaTWZocTI0?=
 =?utf-8?B?bGtSbWl0U1pHWHVOcWVPc1JIbjJyeDVWbUNCdnl6YVZHY2hNU2VlRHRUcVll?=
 =?utf-8?B?L2Y5MEN1YnFuOWtMT3ovYlJZZk5WeW9GeDN4T2FWSUYyRTNOSVFGVUVpc2c1?=
 =?utf-8?B?NnNwczhwQ0wxeVJsenNadnV1RytSREh5VGMySHJSVzUvaFNVWEVlaDM5U3dX?=
 =?utf-8?Q?hkCxfCB3858uPFA7KNe3s70RW?=
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: base64
MIME-Version: 1.0
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-AuthSource: SJ1PR11MB6083.namprd11.prod.outlook.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 50126083-46ea-4587-a748-08db1f6d2e46
X-MS-Exchange-CrossTenant-originalarrivaltime: 08 Mar 2023 00:36:39.1023
 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: 46c98d88-e344-4ed4-8496-4ed7712e255d
X-MS-Exchange-CrossTenant-mailboxtype: HOSTED
X-MS-Exchange-CrossTenant-userprincipalname: S4KUp51bI+BsrnnPJ+MGZsfkB2gTB14OwqRVe0okJHvtDWNySIFcLIAaddWxmH2Lj76+YUOhOyTogEVp+vo4Lw==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: SA3PR11MB7582
X-OriginatorOrg: intel.com
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org
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=