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;
Message-ID: <6f4402cd-3f05-373c-93c3-581491fd5116@meta.com>
Date:   Mon, 12 Jun 2023 08:22:01 -0700
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0)
 Gecko/20100101 Thunderbird/102.12.0
Subject: Re: [PATCH bpf-next 3/5] bpf: Replace bpf_cpumask_any* with
 bpf_cpumask_any_distribute*
Content-Language: en-US
To:     David Vernet <void@manifault.com>, bpf@vger.kernel.org
Cc:     ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org,
        martin.lau@linux.dev, song@kernel.org, yhs@fb.com,
        john.fastabend@gmail.com, kpsingh@kernel.org, sdf@google.com,
        haoluo@google.com, jolsa@kernel.org, linux-kernel@vger.kernel.org,
        kernel-team@meta.com, tj@kernel.org
References: <20230610035053.117605-1-void@manifault.com>
 <20230610035053.117605-3-void@manifault.com>
From:   Yonghong Song <yhs@meta.com>
In-Reply-To: <20230610035053.117605-3-void@manifault.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?SnhNajJBTkw4cFRpRWZZY0MrTjFVNE1vcFBRRU9qb1Z5QjdhOWZxQlRNb1Qv?=
 =?utf-8?B?NTBiMmFaVDRETjEzSHRGUUFVMDAvNzJib1BucmhaSzhFdWVZWmw3UWwvL2RN?=
 =?utf-8?B?d2tzci9TOVhnVG1lamNqSmlieGp3U3ZjYys5ZGZ0L20wL0U3SHN0Q1F4aVF5?=
 =?utf-8?B?TjJ4aXZMRld5NXpia1BuOTJXbS9NWGc4UEZYeHA1T3Y2RThrVWlpT0h6Wm1G?=
 =?utf-8?B?M0Z6M3VHS0NwTlBZSm5LWUEyYnU2NkN0YXM4Rjc4UFE0eWFnaTYybC9jbkFv?=
 =?utf-8?B?NDY1OHpZblpmaThWZDN0T0RnQ1VWY1RlclVmZnAvOEJ3MnV1SlJhYjlTNEw1?=
 =?utf-8?B?WjBCSHVnL1IwVml1U0hKcE1rZXY4S21OSmhOYTRlajE4TkJNQjRTejQxcFRv?=
 =?utf-8?B?eDVndFd2MmxLWUE4OU1CNW56VTd0d0tMWmxhZEpybEhkL3VjVGhRODJ6MHpi?=
 =?utf-8?B?aGRSSE4zdjVvNlhzc2FFcUFUT2FQQzRkWDNJL0dBWXVkaHJ1Z3pKdnJjSFda?=
 =?utf-8?B?Mk9iM3FhdFRQZnU1STd1MFQ3YVg5bnduNWJoTk4wR3N2Z3lPdUhaa3RQdlJq?=
 =?utf-8?B?ejhJdXdncjRWY1ZpdVRMTWxpZzZQTERaa1F5eDFuRnEvNmRaL2dQOWJ3Ymh5?=
 =?utf-8?B?SGliTFRvVG1NZmVPYVZhN3IxU0RUc1JvV1psZjU3U3AvY3ZqekZNNVpNTCtl?=
 =?utf-8?B?YTBwNXIrR3ZZU001OTBwZ0RwazJhSDREY3FaQWJNbFNnY203TXk0STRnY0Fk?=
 =?utf-8?B?blFMWFV5d08vb3puZUdWb1Q1MnE3dUJVSEhSUkd3Qmd4SHg4UVJ6UlBRc0VX?=
 =?utf-8?B?QkFoaGY5ZFJGVzEycmQrTE1lVnpHWFZMTlh4VXhWM1Z1aW8rL29UekphZmo2?=
 =?utf-8?B?MDAyU1NvRFhQSm1PeEFoMEFEdlRDaXYzVjRSaEE4M3A3RHJWOFpibFMrd1Vx?=
 =?utf-8?B?UjEyanZ5QVBKQzNiQXlWRUkyM1VsVTJjT0d2azJaZUpRcVliWVFrQXJRV1Zy?=
 =?utf-8?B?NUNEV0t4WmRwbm5UbGtXam11ZlR2enlxdksrNHV2LzF4RnFYOUpqa1llSHYv?=
 =?utf-8?B?OENyVmIyVi82NURUaUZpR1V2ZlBselJZMTlaSEdpTWhXTFUwZUdtVHlLVGZN?=
 =?utf-8?B?RGNBUTNIMG14M05vM0NCNmtVWkxXSVBCbFdGaU43UW9BakZBR3FIZ28wMFZQ?=
 =?utf-8?B?ZUpTUkk5UUVMclh0cldURXJtTDU3ektVdnhpdW9FR2IrODhITENJWWRhQWVn?=
 =?utf-8?B?RjJ1cXVWSkxncFdLNTVFQkMrTWtTMlpqckU5OTVQd0h2em52WkRVNEllRzZn?=
 =?utf-8?B?aGZvVDlVYW5CTUt5cEh2OWV3V1htRVk2V3c1RDcrc1hDSGNjVWphZE40dnMv?=
 =?utf-8?B?NE9vMWR5bkVtTUo4OC9vdlk3MWwxTnFYY3VUWXBsTHNZWUxVclFidHQ3b1ZQ?=
 =?utf-8?B?U05majYzQUdDQk9ETnZVM3ExelpQak9wUzVBTnl0cWlIS3luUHlZWmhza3hI?=
 =?utf-8?B?NFBrV1AwcjZES3JOczkrTHVJV2pxTTUrV0dFZHZCenFFYlVvd0Zrd2lQeE1l?=
 =?utf-8?B?R3BKM0QzSXhySkZPWERyRFFrc3UvTVRkM0VodTRuUnhFRHVtWE9aVkwzanoz?=
 =?utf-8?B?eUxrQUpiWjZQLzRZeXBrNU8xZ0YwSTNIWUFhOEV3VUZzdkwxbmlybFpITjdC?=
 =?utf-8?B?MURCMnZYK3IrR2p2UnNyL1c5OGJvUEpjU3hJTmdxVHRZdDIvYnRwbzZoZWhs?=
 =?utf-8?B?ZXJGdHJDNy9HYmdvSG1uQ29zUmNKY1ZGNm5XY3puMFhHSnZhNnBXaUw0SC9N?=
 =?utf-8?B?cU42cm5vT3lUbFVOajNzN1M0T3lsY2pMaXZIL0tYZVdqbzJBN2xsWDI3TVpl?=
 =?utf-8?B?TkVUQ3NvQ0VvRHg3OVd5eEFFbXVPUWVOc25hNGtQT05xd25QS0V2L2VHNVly?=
 =?utf-8?B?UnFHMC9zd2h4eFVvVTFrNFI3Rjg1d0h0cEZMSjE5MnQrOUt2K2pZb1k4Ym5G?=
 =?utf-8?B?aGdjRThBRzIzREdLSC8vNTNpNVdsbVlVTlZWdVBrakdqQkFDSHVMNklMOTR1?=
 =?utf-8?B?RDFoN2ZHQ1BWK3c2ekROcUlqY0ZEb0FjMmlmbS9FSGZoVE00blM2SlBsTWhB?=
 =?utf-8?B?c2UwQ0tVdGpiS01WaUFBeTVhUVdIdzljeU1JWHJTZDh3dHJZekpEZHV5NUM4?=
 =?utf-8?B?aWc9PQ==?=
X-OriginatorOrg: meta.com
X-MS-Exchange-CrossTenant-Network-Message-Id: fd7a29a6-f94c-4ed6-c1a4-08db6b58c73f
X-MS-Exchange-CrossTenant-AuthSource: SN6PR1501MB2064.namprd15.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 12 Jun 2023 15:22:04.8590
 (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-CrossTenant-UserPrincipalName: wFrxh54B6MS+8ubYCQ3j7lRcGo6POF28+B7dmpYoNKvP0sp2K6I47PiUgkiVsA6j
X-MS-Exchange-Transport-CrossTenantHeadersStamped: DS0PR15MB6067
X-Proofpoint-GUID: DkmqHRpKLNRZ7CoCVl6rA-FiZP6Gr2KH
X-Proofpoint-ORIG-GUID: DkmqHRpKLNRZ7CoCVl6rA-FiZP6Gr2KH
X-Proofpoint-Virus-Version: vendor=baseguard
 engine=ICAP:2.0.254,Aquarius:18.0.957,Hydra:6.0.573,FMLib:17.11.176.26
 definitions=2023-06-12_06,2023-06-09_01,2023-05-22_02
X-Spam-Status: No, score=-2.9 required=5.0 tests=BAYES_00,DKIM_SIGNED,
        DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,NICE_REPLY_A,RCVD_IN_DNSWL_LOW,
        RCVD_IN_MSPIKE_H3,RCVD_IN_MSPIKE_WL,SPF_HELO_NONE,SPF_PASS,
        T_SCC_BODY_TEXT_LINE autolearn=ham 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 6/9/23 8:50 PM, David Vernet wrote:
> We currently export the bpf_cpumask_any() and bpf_cpumask_any_and()
> kfuncs. Intuitively, one would expect these to choose any CPU in the
> cpumask, but what they actually do is alias to cpumask_first() and
> cpmkas_first_and().
> 
> This is useless given that we already export bpf_cpumask_first() and
> bpf_cpumask_first_and(), so this patch replaces them with kfuncs that
> call cpumask_any_distribute() and cpumask_any_and_distribute(), which
> actually choose any CPU from the cpumask (or the AND of two cpumasks for
> the latter).
> 
> Signed-off-by: David Vernet <void@manifault.com>

Acked-by: Yonghong Song <yhs@fb.com>