Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   Nadav Amit <namit@vmware.com>
To:     Dave Hansen <dave.hansen@linux.intel.com>,
        Thomas Gleixner <tglx@linutronix.de>
CC:     LKML <linux-kernel@vger.kernel.org>,
        Hugh Dickins <hughd@google.com>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        X86 ML <x86@kernel.org>, Linux MM <linux-mm@kvack.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Andy Lutomirski <luto@kernel.org>
Subject: Re: [PATCH v2] x86/mm/tlb: ignore f->new_tlb_gen when zero
Thread-Topic: [PATCH v2] x86/mm/tlb: ignore f->new_tlb_gen when zero
Thread-Index: AQHYlPRIBVYGglwRp0y21cAEvAmJeq15cHiAgAIF64A=
Date:   Wed, 13 Jul 2022 00:33:19 +0000
Message-ID: <3DC1239B-FBE4-4EE0-B0D1-641B64697712@vmware.com>
References: <20220710232837.3618-1-namit@vmware.com>
 <7672923F-D439-4867-9418-B1F44EE5CC44@vmware.com>
In-Reply-To: <7672923F-D439-4867-9418-B1F44EE5CC44@vmware.com>
Accept-Language: en-US
Content-Language: en-US
x-ms-exchange-antispam-messagedata-chunkcount: 1
x-ms-exchange-antispam-messagedata-0: =?us-ascii?Q?POabjnJ+coLpf/rOyZAotS6NLWIjCmsTxJ0cf6KTBsaLTFPI8AmJkVcZt/u4?=
 =?us-ascii?Q?MkU62X88XT9XiFFOljQiBYlHvovFykY1DorXUhezSdFQW87QUcNviGMsbrJr?=
 =?us-ascii?Q?rQ0ythCNE5SdSDjbhX/Ikq63T5OZ3AzIN8Vc43FkuRyQEXOwltEFwLvtNqkJ?=
 =?us-ascii?Q?87FjbuZsJLx5ZogMu7go4qyfLjXR6NRR4Yn+Ds94Ueb3ZCtIH5DDmojbSr0X?=
 =?us-ascii?Q?4jlktvsutKOPXSoO5BMaMOMW+xXU6tqPALZ4dXlCqOyNnwEpj9Bu1wyAR540?=
 =?us-ascii?Q?EuR6ePE1u5xz7hSFNzssNzYBOQPKH8sxcaK1CrESJlO79W9ge2fCFzPP9vcv?=
 =?us-ascii?Q?p2r99HHqVTu/PB0sxRHc3MXSHI/lJHe4oZvCXDkdGJ/WrtVY9rkPGLqF/h3a?=
 =?us-ascii?Q?lD8KqSbTq/YijSGq5fOPv3oAJCXQGS3JDZIeGPK+0aqmOiLMwK4I/R/IeN1J?=
 =?us-ascii?Q?d3U0vOk7ipRKF+xpPaWHL0wegomlJrKbCFni0NgMaaCMfijKooDHFfGqTfrA?=
 =?us-ascii?Q?1GrvGHIOFPVR0z7udN4X2qgLPfEOoJ0XHhYZk9UixP6ukWfpncJwfP3YVLTa?=
 =?us-ascii?Q?qdIc+Hhyc7J7N1/QuuV5P/96yD6Nv2i1ZExK+c/eyvSFh0Aa0Z2hpIn2jBZD?=
 =?us-ascii?Q?RG6STWalOKoRFNcwpW7WBzl8ovLGkyXgB3jalkl+cCn16ypsFvXHaLuWtVQt?=
 =?us-ascii?Q?ydfoFfvXl5T4xbh3rn/Q/dPG9zY4UTJPLfTBnHLkAyuGILh+OAeYlbZpW33e?=
 =?us-ascii?Q?n+6AS641rbWUi9FS+u67zv2OcwXDpAnJehSplJFawVqCrKdXEObQsROfGKUf?=
 =?us-ascii?Q?ECNGtDaqUzVyA9Bp9NEvCPX4MmSDBrtaWFcY6RzgUB+YGeOLnmDXATnYWsfI?=
 =?us-ascii?Q?sTLOgreQaft8idIj/Vds1MyKT1Xi6K/k3kG0+FEuzYrmUnN//anZaGRUicse?=
 =?us-ascii?Q?AWRrEpNmYWatOw0pSlvV1S97XfRIxDbrO+qAjBfGXM3GiLz7blppKDelD2zN?=
 =?us-ascii?Q?3VoaQtW4wePuVdhAjx4BwfbLHrXd0IRhAKVf7EROk+8QFnJr/5aJg6sTafWt?=
 =?us-ascii?Q?ch74J9+jycmaVTC4GXaebRxsjZbbT7ghmzs7Zk/4CaU1CrP9qpNYBOueldAb?=
 =?us-ascii?Q?cKjiKI3Na3ExgJ7kLjp8UkTWzOqWcY0uyrxOWlHTdjIi4KWHqDYeU10QSuBE?=
 =?us-ascii?Q?OP/6UAZVfPGLlj5f/IdfcJvmkjRrUfkxyvXCRaxUyqW204H4fPapLg3GwtsP?=
 =?us-ascii?Q?3SzR0WkI06JePZCFQsHl+LCWFEjV7R1LYeGfLLfb692oA5pKofMnECi74Koh?=
 =?us-ascii?Q?uOi7oU2x/Pm6e95qGCg+kq/+QnJA6IpbM9vSBA4sFM1XzfabyMdZ5We5yP8b?=
 =?us-ascii?Q?D6G1mXWdieJGkrEQAwOCc0WcMz9Rwu0m4CPe+U4YpmcUPOf/NtkOCbX2l/RY?=
 =?us-ascii?Q?GGWGrinB6wmeaNGoE4x1Vh6XLJImOznnIdIJzwmUFbrT1cIu6i3jD+HWRMyq?=
 =?us-ascii?Q?xV520krXLs5PZvV74NxavfPKMAehOjxLW00/aLIHZnaBWsOhbg3+vw3o8ZyB?=
 =?us-ascii?Q?6nE/CMGsrJq4H6Ln5IDg+FD1lH24pPD14swMdru8?=
Content-Type: text/plain; charset="us-ascii"
Content-ID: <E75D2D5A27B67F45B73BB2D7D29E73B4@namprd05.prod.outlook.com>
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
X-OriginatorOrg: vmware.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-AuthSource: BY3PR05MB8531.namprd05.prod.outlook.com
X-MS-Exchange-CrossTenant-Network-Message-Id: fcc0a909-dfa4-4f25-6ea1-08da64674941
X-MS-Exchange-CrossTenant-originalarrivaltime: 13 Jul 2022 00:33:19.9468
 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: b39138ca-3cee-4b4a-a4d6-cd83d9dd62f0
X-MS-Exchange-CrossTenant-mailboxtype: HOSTED
X-MS-Exchange-CrossTenant-userprincipalname: +w59IHpDXi6uVolpTAGnS6nrEZiiyk461opJMqpsTmPRu9pRDZx3xaSWbSjZWt+asP8S9vyRRzDypPz2aYG1CA==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM6PR05MB7145
X-Spam-Status: No, score=-1.7 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,
        DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FORGED_SPF_HELO,
        RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H2,SPF_HELO_PASS,SPF_NONE,
        T_SCC_BODY_TEXT_LINE autolearn=no autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
        lindbergh.monkeyblade.net
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Jul 11, 2022, at 10:39 AM, Nadav Amit <namit@vmware.com> wrote:

> On Jul 10, 2022, at 4:28 PM, Nadav Amit <nadav.amit@gmail.com> wrote:
>=20
>> From: Nadav Amit <namit@vmware.com>
>>=20
>> Commit aa44284960d5 ("x86/mm/tlb: Avoid reading mm_tlb_gen when
>> possible") introduced an optimization of skipping the flush if the TLB
>> generation that is flushed (as provided in flush_tlb_info) was already
>> flushed.
>=20
> Dave,
>=20
> Can you please review this patch today?
>=20
> I feel bad (for a good reason) for breaking swap/migration.
>=20
> Thanks,
> Nadav

Ping?

As you know, this really must go into 5.19 or otherwise aa44284960d5
reverted.