Received-SPF: pass (google.com: domain of linux-kernel+bounces-74692-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.80.249 as permitted sender) client-ip=147.75.80.249;
Message-ID: <15fcf98c-58c5-fa08-2e21-f3b0baf058e6@amd.com>
Date: Wed, 21 Feb 2024 17:53:36 +0530
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101
 Thunderbird/91.13.1
Subject: Re: [PATCH 00/30] PREEMPT_AUTO: support lazy rescheduling
Content-Language: en-US
To: Ankur Arora <ankur.a.arora@oracle.com>, linux-kernel@vger.kernel.org
Cc: tglx@linutronix.de, peterz@infradead.org, torvalds@linux-foundation.org,
 paulmck@kernel.org, akpm@linux-foundation.org, luto@kernel.org,
 bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, mingo@redhat.com,
 juri.lelli@redhat.com, vincent.guittot@linaro.org, willy@infradead.org,
 mgorman@suse.de, jpoimboe@kernel.org, mark.rutland@arm.com, jgross@suse.com,
 andrew.cooper3@citrix.com, bristot@kernel.org,
 mathieu.desnoyers@efficios.com, geert@linux-m68k.org,
 glaubitz@physik.fu-berlin.de, anton.ivanov@cambridgegreys.com,
 mattst88@gmail.com, krypton@ulrich-teichert.org, rostedt@goodmis.org,
 David.Laight@ACULAB.COM, richard@nod.at, mjguzik@gmail.com,
 jon.grimm@amd.com, bharata@amd.com, boris.ostrovsky@oracle.com,
 konrad.wilk@oracle.com
References: <20240213055554.1802415-1-ankur.a.arora@oracle.com>
From: Raghavendra K T <raghavendra.kt@amd.com>
In-Reply-To: <20240213055554.1802415-1-ankur.a.arora@oracle.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0:
	=?utf-8?B?Mm56Y3pycFk2NFY0NjNTaXpvRWo5YURuUFFxRm9tVWZqZ3ZiWXkzaDdlV2Fq?=
 =?utf-8?B?cEZiRXlONHZBYTYwcFp4eGp1a2xjcVA0NFV4TGNoZENORUpvT0pYbXVsbG5Z?=
 =?utf-8?B?d1pvbGlFTGpYUUxHcjJhclpXWGhtRTBIeDYxUTc4ZlE1N244N3kxb042OGZX?=
 =?utf-8?B?WmJjVHFBcTZKMkVJV3NRdEZqYUVQV3pKUHR5aU1NOUlzSEZ4TGhqYXU1NmFl?=
 =?utf-8?B?K2VUQ0dEdkFacW42d0s5clB2YXIxL3Vid2VlMkRPcDlQTHNEc08vM1hpK0FZ?=
 =?utf-8?B?c0V3YUJsTFVYMVBUcUdCSndNYXBTYnFwVENBTE15VGYxSitjaUN1aUxpSStD?=
 =?utf-8?B?WUdZajlBbFF3Ulk2Y0dvSWR4V0xWUkIrLys5Z1p0My81YUtaY1hXSVlUOVFU?=
 =?utf-8?B?OVpRblo2Y1lSNXE0TVNQRTFJbmJJdWZCNzRrcDQ1UnJQdndUYy82Uld6ck1U?=
 =?utf-8?B?OHFoUFFSMjFMZDNONU4rSTF2WURURTYyQ2pYL1dEaUwvckxHbHVnbURlMVFk?=
 =?utf-8?B?eGFNUDk3UzZGYVNrNklZeEt2SG9kNlRldWVPMVluQ2dFbDRRQ1RhVnZyUWlE?=
 =?utf-8?B?bnZTYnNkM2ZXaFVRYWFic2wrMW82MXNZcmVyT0FYY2IrRE5qQWJZOEhkQjNj?=
 =?utf-8?B?ZCtGdGU3UlVLc0ZJYzdzc3VwbTVraTFHREtyYXplYkJNc3Q1YWtVSXpGSHhv?=
 =?utf-8?B?bnNrQUhjVk5pVElWL3pYRkx3MDhHMkdyYUY0NjVuUkhIVllISXVMMEluK1JU?=
 =?utf-8?B?QlpzL2pQUW9wL3p2Y2FKNUNVYmxQc0hYbkQ5L2xHM1JxaUdvdHNUVXFRM081?=
 =?utf-8?B?c2FrcVRGMllVbDlEenZzUm5UL0RCVnNTaklZRVhMNmRFRHJRcDRnTUxtR3Vj?=
 =?utf-8?B?Qkh0RExJcXZTbkEzU015R0ZkbkpzaWN0WmlrK3d4Y3Y3cHNKNmhJTHlYcEpT?=
 =?utf-8?B?Rkc2WG5CSkhqZFRJTWVwUkFENVVsY1E0NzhQUFZqR04rK1NJSG91ME43MzZJ?=
 =?utf-8?B?YjhyemFjc0ZJalNvazF0U1hnUVBXYWJtb2Z6VkVmY2NJTW5IRThMRm1xZTd5?=
 =?utf-8?B?aVZIUkdEY0pqOXBIZ011L25rUkNoMVN4b3NYc2V0U2tvZlBxTXdRZnZKOElF?=
 =?utf-8?B?N0dBbG0vRkJRaHJBVllRWk11dzhUeG5tcWkvMjFQTzBWekRXOGIwYlhTazN1?=
 =?utf-8?B?bXFaZ0l0aGhHNUdLUmZ0aGFrd0k3QlYvRnh6a0NNd0hmUHNDUGtRb3lZbjhP?=
 =?utf-8?B?bXlXcVJPMDBzeE5peTJmYUJTUDRGTEZiMWsyeWVRNlVLVUpNNU0xSmd4TG1j?=
 =?utf-8?B?aFVwOHYwWHgzVmJQQll2cXZGcXlqRkFFU0hKQVEwU0JMSEwxcVR5a3lCMlRv?=
 =?utf-8?B?T2txZkxYVUkzNTBTNzZIbENOYksrU0FZSUw0YVliYzVMenhQd0dmQ2lpNFp5?=
 =?utf-8?B?bWVYTTIyTmtKbVF1YlVaQnpVSUpmV0xtbDFXZGxBSW9tMWlnYlRaYXZtWUJI?=
 =?utf-8?B?QXhVRWo0elBpT0N1Z05lbHpaRlpmNUY2ay85QlJRVitQNVlvYkppVmpqTll4?=
 =?utf-8?B?MnAraVVWcXkyVS9PYlNYNWVGRVBkeUFiR2RLWDFxaFFwRklDVklYSG5jalhQ?=
 =?utf-8?B?aGxIRzAwcjJ0anZOeW9lZEt1a3RtUFVyQngwTkNIb29vcEFmclBENTAzRFFH?=
 =?utf-8?B?amVsYmRjM2dxS2hCakFrUUdKSzFNRFlMa2haSHE2WGE4dWxWU0o2MmViaVkz?=
 =?utf-8?B?b0xQQmFYYTBVRS80ZTNlWm1JSTJMQ29MV1JsMnZ2b0MwUTdPaGc3MmU0VWFE?=
 =?utf-8?B?WnM0QjZvNnBid2ZrYmQzdHBZOW5PZGFCNGRCb3ZpNWZzZW9XZHFIaGpJeDg1?=
 =?utf-8?B?RnIvZk9NbENmZ0kvRGRlY1RTN1pYWktnQXNpeE1vRFVMUjZEWUw2Z2orN241?=
 =?utf-8?B?UTl6QUI3alBLNURsdkNza0VVS0JGNjVyVkU2MktFU0Q3OGhOTUZNcWN4MUIv?=
 =?utf-8?B?Y1FFZWV3U2NNR0VRUCtKV2NtTm9PMFRDRHpkWWJkdUE4bWt0eEhXWEFWbUpM?=
 =?utf-8?B?d2p2NXJPSHRvNHM5UmNWTEYwTnpqZWJzTCtNV1BWd3BKdTZUR0o3Wk02N0pF?=
 =?utf-8?Q?ooidDILMOd6m+4QWpkbak0/wy?=
X-OriginatorOrg: amd.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 093da4f9-4c06-4979-52d5-08dc32d7f73e
X-MS-Exchange-CrossTenant-AuthSource: PH7PR12MB5805.namprd12.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 21 Feb 2024 12:23:52.8921
 (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: 5DVX4bE6b/1aXbzwiTcSUXm4NXGX4tkNYToQXt98zta45bWytWfVS/Wt7I0fUCQUZdalduFVQLHDWWQTSKIjqg==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: CY5PR12MB6528

On 2/13/2024 11:25 AM, Ankur Arora wrote:
> Hi,
> 
> This series adds a new scheduling model PREEMPT_AUTO, which like
> PREEMPT_DYNAMIC allows dynamic switching between a none/voluntary/full
> preemption model. However, unlike PREEMPT_DYNAMIC, it doesn't depend
> on explicit preemption points for the voluntary models.
> 
> The series is based on Thomas' original proposal which he outlined
> in [1], [2] and in his PoC [3].
> 
> An earlier RFC version is at [4].
> 

[...]

Hello Ankur,
Thank you for the series. Just giving a crisp summary since I am
expecting a respin of patchseries with minor changes suggested by
Thomas, Mark and a fix by Paul. and looking forward to test that.

I was able to test the current patchset rather in a different way.

On Milan, (2 node, 256 cpu,  512GB RAM), Did my regular benchmark
testing, to see if there are any surprises.

Will do more detailed testing/analysis w/ some of the scheduler specific
tests also after your respin.

Configuration tested.
a) Base kernel (6.7),
b) patched with PREEMPT_AUTO voluntary preemption.
c) patched with PREEMPT_DYNAMIC voluntary preemption.

Workloads I tested and their %gain,
                    case b                   case c
NAS                +2.7                    +1.9
Hashjoin,          +0			     +0
Graph500,  	   -6 			     +0
XSBench		   +1.7			     +0

Did kernbench etc test from Mel's mmtests suite also. Did not notice
much difference.

In summary benchmarks are mostly on positive side.

Thanks and Regards
- Raghu