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Harding" CC: Andrew Morton , Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Matthew Wilcox , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH v5 4/7] slub: Add comments to endif pre-processor macros Thread-Topic: [PATCH v5 4/7] slub: Add comments to endif pre-processor macros Thread-Index: AQHU6ajBwVxIgIrx7ESbIcbajaDpPaYqxqMA Date: Wed, 3 Apr 2019 18:42:27 +0000 Message-ID: <20190403184223.GD6778@tower.DHCP.thefacebook.com> References: <20190402230545.2929-1-tobin@kernel.org> <20190402230545.2929-5-tobin@kernel.org> In-Reply-To: <20190402230545.2929-5-tobin@kernel.org> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-clientproxiedby: MWHPR15CA0041.namprd15.prod.outlook.com (2603:10b6:300:ad::27) To BYAPR15MB2631.namprd15.prod.outlook.com (2603:10b6:a03:152::24) x-ms-exchange-messagesentrepresentingtype: 1 x-originating-ip: [2620:10d:c090:200::1:9220] x-ms-publictraffictype: Email x-ms-office365-filtering-correlation-id: 1a100f5a-df1e-43fa-e835-08d6b8641ecd x-microsoft-antispam: BCL:0;PCL:0;RULEID:(2390118)(7020095)(4652040)(8989299)(4534185)(4627221)(201703031133081)(201702281549075)(8990200)(5600139)(711020)(4605104)(2017052603328)(7193020);SRVR:BYAPR15MB3480; x-ms-traffictypediagnostic: BYAPR15MB3480: x-microsoft-antispam-prvs: x-forefront-prvs: 0996D1900D x-forefront-antispam-report: SFV:NSPM;SFS:(10019020)(396003)(136003)(39860400002)(376002)(366004)(346002)(199004)(189003)(6486002)(33656002)(46003)(14454004)(478600001)(76176011)(6916009)(97736004)(2906002)(186003)(102836004)(25786009)(256004)(6506007)(386003)(229853002)(105586002)(106356001)(53936002)(305945005)(6246003)(7736002)(6512007)(9686003)(476003)(446003)(68736007)(11346002)(86362001)(486006)(99286004)(5660300002)(8676002)(54906003)(81166006)(316002)(4326008)(81156014)(4744005)(6436002)(52116002)(71190400001)(71200400001)(1076003)(6116002)(8936002);DIR:OUT;SFP:1102;SCL:1;SRVR:BYAPR15MB3480;H:BYAPR15MB2631.namprd15.prod.outlook.com;FPR:;SPF:None;LANG:en;PTR:InfoNoRecords;A:1;MX:1; received-spf: None (protection.outlook.com: fb.com does not designate permitted sender hosts) x-ms-exchange-senderadcheck: 1 x-microsoft-antispam-message-info: +Nc1/yugvQ/RfQ3Wk+HlCrw7Yhm0yP41l1gCFADH+ygKID9uz1HcX3gKdMhod1QDcWH9SZQZjhmRTiBpHu/ajPcPGGb4zTn2pb9SNXZiNg+eRo8U5dCEbgPITFJVIDmSa/38QkuZ/FFvXtjxJSYkW6IOjLKocOrIG0WZMPVQ3NZMUnm/6SRRsnljIATBlF783i7feCQtCTNmJHeNCpvdkc0qdWYxH35jrh59Lqvdof2Q+OROTsaqPr7JTvY6CL4lqH/BE4WoID8sFsqsd635tybIY/inolCIkbRb2q7KLk2Ql/5aFowJywAIyo0M6NSelov8QX/8hyYepQMLN59aPZPLeEscNU53Ebf3vuxXRVlMrH6hL84Y1gDr9UYj8iMo/K4wdeB+HKC5YQ0B9VmqV+XepTywJVwEcQD7bdkj334= Content-Type: text/plain; charset="us-ascii" Content-ID: Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-MS-Exchange-CrossTenant-Network-Message-Id: 1a100f5a-df1e-43fa-e835-08d6b8641ecd X-MS-Exchange-CrossTenant-originalarrivaltime: 03 Apr 2019 18:42:27.5577 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 8ae927fe-1255-47a7-a2af-5f3a069daaa2 X-MS-Exchange-CrossTenant-mailboxtype: HOSTED X-MS-Exchange-Transport-CrossTenantHeadersStamped: BYAPR15MB3480 X-OriginatorOrg: fb.com X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-04-03_10:,, signatures=0 X-Proofpoint-Spam-Reason: safe X-FB-Internal: Safe Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Apr 03, 2019 at 10:05:42AM +1100, Tobin C. Harding wrote: > SLUB allocator makes heavy use of ifdef/endif pre-processor macros. > The pairing of these statements is at times hard to follow e.g. if the > pair are further than a screen apart or if there are nested pairs. We > can reduce cognitive load by adding a comment to the endif statement of > form >=20 > #ifdef CONFIG_FOO > ... > #endif /* CONFIG_FOO */ >=20 > Add comments to endif pre-processor macros if ifdef/endif pair is not > immediately apparent. >=20 > Acked-by: Christoph Lameter > Signed-off-by: Tobin C. Harding Reviewed-by: Roman Gushchin