Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.36 as permitted sender) client-ip=23.128.96.36;
Message-ID: <85115845-93c2-9967-c3b1-749b62b22868@amd.com>
Date:   Fri, 15 Sep 2023 08:51:38 +0530
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101
 Thunderbird/91.13.1
Subject: Re: [RFC PATCH 2/2] sched/fair: skip the cache hot CPU in
 select_idle_cpu()
Content-Language: en-US
To:     Chen Yu <yu.c.chen@intel.com>
Cc:     Tim Chen <tim.c.chen@intel.com>, Aaron Lu <aaron.lu@intel.com>,
        Dietmar Eggemann <dietmar.eggemann@arm.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Ben Segall <bsegall@google.com>, Mel Gorman <mgorman@suse.de>,
        Daniel Bristot de Oliveira <bristot@redhat.com>,
        Valentin Schneider <vschneid@redhat.com>,
        "Gautham R . Shenoy" <gautham.shenoy@amd.com>,
        linux-kernel@vger.kernel.org,
        Peter Zijlstra <peterz@infradead.org>,
        Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
        Ingo Molnar <mingo@redhat.com>,
        Vincent Guittot <vincent.guittot@linaro.org>,
        Juri Lelli <juri.lelli@redhat.com>
References: <cover.1694397335.git.yu.c.chen@intel.com>
 <d49cf5748aa7c6d69580315d2373a9eafa21c21f.1694397335.git.yu.c.chen@intel.com>
 <31c910c2-717d-b86c-4e08-5c94383682e8@amd.com>
 <ZP7ptt70uF10wxlg@chenyu5-mobl2>
 <5b35ae2b-a401-2489-4b3a-a03e8284d138@amd.com>
 <ZQBaWRCmMOvIGmem@chenyu5-mobl2.ccr.corp.intel.com>
 <229069c1-3d61-53bb-fff7-691942c48d21@amd.com>
 <ZQElEM5GAn/Vq0tM@chenyu5-mobl2.ccr.corp.intel.com>
 <86f761a4-9805-c704-9c23-ec96065fa389@amd.com>
 <ZQLoAQcQJDCrdOGd@chenyu5-mobl2.ccr.corp.intel.com>
From:   K Prateek Nayak <kprateek.nayak@amd.com>
In-Reply-To: <ZQLoAQcQJDCrdOGd@chenyu5-mobl2.ccr.corp.intel.com>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?T3Rlb1Q1ak5XTmtkVENSOENZWFBmQUJmN0paNVI5eEhuWTdzUC8xSGhGQzRL?=
 =?utf-8?B?bEpGL3dNbXhjTWh2OHZIZzgvenhjaHpteHNSd0dFeXBsNEIvT0t2SGI0Z3pp?=
 =?utf-8?B?akJycE1RZERYYjdEM3RjbkpGVVFmVzE2MytFRU1VYmRsL04yREI2WkhHVzZn?=
 =?utf-8?B?RFZCQzA1d0hYQm5wSHdORkRHeUk2SUtmcmU2N3hReDRSNlpwQkZnVWxkUGNv?=
 =?utf-8?B?ZDhZM0djNWJVakRRU0c4OWduUXh2Q3F6VC93WDVORkZnMDVjYVU1NEE3dGNi?=
 =?utf-8?B?azM5WGx5LzNiS2VLS20xMjR0cVNxdWR1MVI5K091cUZHOHpwY1ZOVmdCM3g1?=
 =?utf-8?B?Y3pZT3BrNlRpRjk2OUg2aEM0c2h4UjM4MjZKaHNnZ3BxYWw5K3ptdm93RUw3?=
 =?utf-8?B?ZEdsRlQ3d004Nm1YbTBKY1NaZWs3ODhPRFNBRVRKTXlDWm8yNTUyV1lCUEw0?=
 =?utf-8?B?WEdXWmVhT2NxanRKS2J3M0JXV2dSTUE5UWdIRTRCQ204dEpUWEs2Rm1saGcy?=
 =?utf-8?B?T1d6ZUhZRVMwWjhnTTg2dWREczJTQnZKc1NXMGpIVU9TWnVESHhvUzNrTFIz?=
 =?utf-8?B?Z2NlcXFCcmI0Zk5WcTJWT2pFTWpVcGpETXM4L3c1U0MyNmZUS3FrZHBnSVhK?=
 =?utf-8?B?SVFvdTVRb2FJWHQ3NjFtVFB0UWRlLzNLYWJKQ3F1NmpJRFNKVmVrYVlhWE5s?=
 =?utf-8?B?dHQrbWhCU0F3MUR1Qm1wNzJFYkF4dnI2ejRPS09rRlFTOGZyUjVBamFSSVRy?=
 =?utf-8?B?ZkE3alk5T1pEdmpKZUV6WGZmNUFlRk92aGQ0TGE5UTFlZ0ZjeW92ZjBQaGFC?=
 =?utf-8?B?a3VDN0RkQ2wwcFVtU3NuMlhYRGdZRDlWSEJBNjU0aWhCQ2dNeEV6MFhhMCtD?=
 =?utf-8?B?dGlZRlAwTnlWYkV6T2lwR1NaK093VjlTTG5hczJNbWc4TlVScDVYYkFGa05x?=
 =?utf-8?B?dWpieFEyZ2lJUjFOMXgrZGJVWE1FU216b2RUeGI0MzRGSVpVbndmc2JmMnls?=
 =?utf-8?B?MmR3QWhnREdPajJjMGtPaGJmWU9DdVJpdzdERlROWnNIZkNXdjdaZUllejMx?=
 =?utf-8?B?bnZCMGpiR3JyT3VGTWloM0VkN2dMRWMvWHVyNGpNanY4cHk0SUk4a2JjYjAz?=
 =?utf-8?B?Z2RnTThIYlk1UEs3WWVqWmd0aDhQMkJzVkRQaDdCdFh4UnM1Wm9uSFFSa1hw?=
 =?utf-8?B?VWZLRWpadUJxRjhQbVVoejI3R2NZbHhZTDZINlo1eFhKbXBrVEtTWVBwU1FM?=
 =?utf-8?B?TlJmM3FDTktuSmdOQmw3QUhxemVjUXNLNDZtUHlvT292b0xlWGZxQi85S0x4?=
 =?utf-8?B?YVZPZHhwU2x4SWdGZ1RINEdQSGRFbEZGNzhvR1E0SndSVTJZMWQ2VFB6clNP?=
 =?utf-8?B?dzVJdFpFakNsb2EwMVc4WEtrUnZXUG5oN3BTbzJjcmp6VWFPbXdFWmlDNVdK?=
 =?utf-8?B?WGQ0LzZRbjFMajBwY3hDbE5vTXluM2JSQ2JBd3ZzWG5OVk9mRkxURWd5bjU1?=
 =?utf-8?B?bm93a3ErYU1aMjNPdFc0WXpLOEVhOHFWWFVMbDBsNmswSXQzWXR1TVBRR1E5?=
 =?utf-8?B?eTJaVkpwUXlsM0E0U1ovWkF6SGpxWDRybnhtaGFSSExMdG9rOFh0YXZwNm1t?=
 =?utf-8?B?N3FsbGRlbEsrWExRb1BzVkg4RUpBWWFhL29ycGQ1RDg2a0xmTTR4Nk1hYzJL?=
 =?utf-8?B?bnNqN3N3eDN1T3NtVkhDcDY2bzdmQW5CL0FKcit3ait6c2l3bXJ4cEFzNHZy?=
 =?utf-8?B?SE1lNHVham9GVzF5N1dqNzlneW5wdi85SkZCSU9rSVNrdEplOGVkb2JYbm5E?=
 =?utf-8?B?L2RaTytxOU9kK0lRaitoN0t6OHFleXJvVlFjSHJvR0RaTXlCSk8wZitudHdn?=
 =?utf-8?B?bGtLNXlYYnZic3lRR2pxRWlOS2Z4eHlRYmU0cGpBRU93S1NrVFhzV1RYeU9R?=
 =?utf-8?B?OVI0RkQ0NVpSYjRkeTJxaElzWGxLa3dTbUhnZHV6WklESlNlL00xRmhyOGJ5?=
 =?utf-8?B?WWpxMldvaytsbksvNTFoaUZiOHd2SGtkOFVwYTFPZGc1Ym9mTEdrOGVvVFYv?=
 =?utf-8?B?RitiTHpDTlVGZFN3TUdSaDRkb3JWV25LbnFxN1pYVktDVWt3aVRuOUxDRERT?=
 =?utf-8?Q?kDQdGiPdcI2VtInWiEZl2Hgt8?=
X-OriginatorOrg: amd.com
X-MS-Exchange-CrossTenant-Network-Message-Id: bbb9de23-7a95-44c8-f157-08dbb59ae5f1
X-MS-Exchange-CrossTenant-AuthSource: MW2PR12MB2379.namprd12.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 15 Sep 2023 03:21:50.0218
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: HK0PoDptDspbQB3+iN5QPoeGVQFmWMBc4RmYN9Xg9mR9O2RjmPvOD6AvUIM2TCSsnrExoTSz6df5mMSccfdpcA==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: LV3PR12MB9236
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org
X-Greylist: Sender passed SPF test, not delayed by milter-greylist-4.6.4 (pete.vger.email [0.0.0.0]); Thu, 14 Sep 2023 20:22:00 -0700 (PDT)
X-Spam-Status: No, score=-2.3 required=5.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED,
	DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,
	MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS
	autolearn=unavailable autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on pete.vger.email

Hello Chenyu,

Thank you for taking a look at the report.

On 9/14/2023 4:31 PM, Chen Yu wrote:
> Hi Prateek,
> 
> thanks for the test,
> 
> On 2023-09-14 at 09:43:52 +0530, K Prateek Nayak wrote:
>> [..snip..]
>>
>> Meanwhile, here is result for the current series without any
>> modifications:
>>
>> tl;dr
>>
>> - There seems to be a noticeable increase in hackbench runtime with a
>>   single group but big gains beyond that. The regression could possibly
>>   be because of added searching but let me do some digging to confirm
>>   that. 
> 
> Ah OK. May I have the command to run 1 group hackbench?

This is actually perf bench sched messaging. The cmdline from the runner
is:

	$ perf bench sched messaging -t -p -l 100000 -g <# of groups>

> [..snip..]
 
--
Thanks and Regards,
Prateek