Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:6 as permitted sender) client-ip=2620:137:e000::3:6;
Message-ID: <bced7bc7-c489-7a57-374f-62818cbfded6@intel.com>
Date:   Wed, 27 Sep 2023 15:58:33 -0700
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101
 Firefox/102.0 Thunderbird/102.15.1
Subject: Re: [PATCH v2 3/4] Documentation/x86: Document resctrl's new
 sparse_masks
Content-Language: en-US
To:     <babu.moger@amd.com>,
        Maciej Wieczor-Retman <maciej.wieczor-retman@intel.com>,
        Fenghua Yu <fenghua.yu@intel.com>,
        "Thomas Gleixner" <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>,
        "Borislav Petkov" <bp@alien8.de>,
        Dave Hansen <dave.hansen@linux.intel.com>, <x86@kernel.org>,
        "H. Peter Anvin" <hpa@zytor.com>, Jonathan Corbet <corbet@lwn.net>
CC:     <linux-kernel@vger.kernel.org>, <linux-doc@vger.kernel.org>
References: <cover.1695371055.git.maciej.wieczor-retman@intel.com>
 <308c92438288a45a12330af83aa0088a31f60343.1695371055.git.maciej.wieczor-retman@intel.com>
 <17079b9e-4efd-4258-2b5f-afc6d3ae2c0f@amd.com>
From:   Reinette Chatre <reinette.chatre@intel.com>
In-Reply-To: <17079b9e-4efd-4258-2b5f-afc6d3ae2c0f@amd.com>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: 8bit
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?ek5JTDJidEtkTCtzVXdpWHRwN3lmRnFaNFBSTThaNnJiRXhkak5ya1RlTVl0?=
 =?utf-8?B?ZHNxN0h3Z1RzNWdCOTlLSzBHSmNoSGFVcTRYRVVWcHpOekNDNVZKWWs0R3Mr?=
 =?utf-8?B?SDdrdFRjV2RmMnR1dFpOQ1F4eXZodHZiUC9UaHhmV0lubTlGLzloMlVRSGFt?=
 =?utf-8?B?TUpxVUV4T1RkdEN1c3RkZUdtODNZZ0xXREdYc0UvZWxSMmtmQzVmM0IwNWJC?=
 =?utf-8?B?cXYxME03Z1dYcGVjOHFQeDJ3dEVGbm45L2J1dVUzd3R1amdCVHk3Q3ZCUDdE?=
 =?utf-8?B?TzlvTnQ0ZWwrcDErZ2hTV1NqaHMveTNKdkZDZExLdkRWNzltSEtoTlRCUU43?=
 =?utf-8?B?V3RkNXNkRXJLZ042ZVZTeTd1L25FNjIvMnI0Vy81YXlEL3JZbWRGeksyY0Ew?=
 =?utf-8?B?L3dESDJybUwwWnIwNy9OUEZFWUdBRlFBalJjYkhjbVhyejJYSjBpNmt6NHNM?=
 =?utf-8?B?emFQajBzNGhxMGNlSkVPaDh5R1NpNlRMUXY3YnJzVVdPTWFvUkMzQTlYSzNG?=
 =?utf-8?B?a2xVUk5WaHNlT1VpWnQvNzFHUzhHTlBGRmZ2dklkendzWFpyUmNYbnBUL3k2?=
 =?utf-8?B?WkZqS2hnanVYdy9LRUNyRFh1OCttY0JpRjNXYkd1b1lDcXBGSjVtWWJzNk9W?=
 =?utf-8?B?Zkdjem04bzUva3R1TnhUS3EzRTlaSTZ5cUJhajY3OUxFRi9DVnBHY1pNejQv?=
 =?utf-8?B?TG9yU0tHRG5GMGtiZ3h3eElMZFljOTZ1WHFQd0dRdFk3NWl5L2Vrd3dSMWFi?=
 =?utf-8?B?NjdvZG1pR0s0SFBNUWo3enA5VG5HQXdMMUVZZ242TWVrQ2tldTFVOE8zNURa?=
 =?utf-8?B?VkxUaUFtVW9BMXNSWDJsUGxVRFVreXJnenZEVlhTaURRWlIwaVlVMmlXV1dr?=
 =?utf-8?B?Nm1adzk1ZXhIRVRhUFU4THpjb1B4bWE0cm14QkdpR0xlVitwSnpZYTM2akNM?=
 =?utf-8?B?eTdCMzNNSXlwTmZXaWwzVHdTend0VDVXQjh6cSt1MUNINWptWGRKL3pHYk1v?=
 =?utf-8?B?QjFydS81a09HUEM2ZjBFVjRXVnlKNnlrazdVbVorZlRwMUdZTEl3WldDdHJ4?=
 =?utf-8?B?amVNNEVraTZQYjFiM1hPMWZZd09ybGpOcldLTmJYSFBuSjVUYzlRMmNGMllx?=
 =?utf-8?B?dW1oYXpmT3FyTkdFampuckwzT01xUVQwVmN2S2ZwaEZOaEpGWUFlbUR1MERl?=
 =?utf-8?B?d1VaWUNGUlJLY3JrN0xuYmxrS2dvUytJT0JVWnhod0s0MUJ1eUhWeGJvZE5T?=
 =?utf-8?B?VmZLY1JCSk5SenpQQy95MTJua2IyL1QveWtkRE1FUnQvY1hXbC9FZ0RFTUM3?=
 =?utf-8?B?bWI5SENjSnE4UzRCK0E3aHRITzQybURmRDdKRUovNEpwREFsN3NNeEIvYnhn?=
 =?utf-8?B?RWxEellsT0RvZUtlOVI2bnFzdmZ0cWxhSThQQlNaOG9EenZsTi9UNzUvSFI3?=
 =?utf-8?B?bENBcHFkbFFFSWNFQU9wb1JJYUpXUHk5WEFyMzFEcG1YdmsybjMvWWJCL0w0?=
 =?utf-8?B?TElTWVg3N1duWHNSM2l0c2doRW85YTA3YWcyNG5ITVJmTHlJVUNHTUtHYUJn?=
 =?utf-8?B?TjNQaVcyaGxFN2NFS2RjT0tlQmlJRkNvUGhoeDR2MDNvRHZIQkJGK3JqeVhD?=
 =?utf-8?B?MExjUmpBNEVQMVNXTUhRZHRoY3J6OGh5UnN1bW05Q2xSWkgzYzNiTGQ3ZVFT?=
 =?utf-8?B?NzZ2bXg5eGxDTmMvTEFIZ0JLMzRCOWZRNjBtWEpCK2NvdHd4ZFpVd1BMSjl2?=
 =?utf-8?B?VGpSWXJuY2hzOFFHZHZra0hmZVJWSmJjbnM2Z25GeGRtK3cwU1dzZVkvajFP?=
 =?utf-8?B?ZiswWGRsalk5Q2hma0VJT2pHeEJ6Wk1jVW9LT2hqdm9QWXFUdExJTll4OU56?=
 =?utf-8?B?Q25uZWxpZHhqSlhqcjdpeCtRY2Z5aUZ4OWFzRUlVRHVVNWRxcnl3cUpkQUVk?=
 =?utf-8?B?TEIrZWRkemtJSVFGVDVhZUdFQndkS1BGcGNOeFVGOU9MKzJTZlkyRXY2Z2Np?=
 =?utf-8?B?Yk5PdkpJV2F1TytYVWk4N2s2RTVuaTdqVGUzeGRVNG8wWU43RmVzS1U2OG9E?=
 =?utf-8?B?cXhkVUZYcWhYRkhaamQwa2hEMEV1SjJFRSs5OHNsYmlMVDM5V0RWTXAydEVP?=
 =?utf-8?B?d2tRVTh2blBDNHo2V3dKUW5hWWhwTVlpVFpGZ1AvM1I5dkUzSzBUVmVtTUtZ?=
 =?utf-8?B?dlE9PQ==?=
X-MS-Exchange-CrossTenant-Network-Message-Id: 6eb2f696-5925-4621-ca62-08dbbfad4ad1
X-MS-Exchange-CrossTenant-AuthSource: SJ2PR11MB7573.namprd11.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 27 Sep 2023 22:58:41.0338
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 46c98d88-e344-4ed4-8496-4ed7712e255d
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: z0b1VWshgOWLJtY0q3vbVOnM2v81GaNB7EDYXzCheGBG874VBBxkZFHE+aLCy2l29q08vAbMbcYuOGEzbqRDszVCdhjG+6s+jl3sHUUGvTU=
X-MS-Exchange-Transport-CrossTenantHeadersStamped: PH0PR11MB4853
X-OriginatorOrg: intel.com
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
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]); Wed, 27 Sep 2023 15:59:07 -0700 (PDT)

Hi Babu,

On 9/27/2023 3:47 PM, Moger, Babu wrote:
> On 9/22/2023 3:48 AM, Maciej Wieczor-Retman wrote:
>> From: Fenghua Yu <fenghua.yu@intel.com>
>>
>> The documentation mentions that non-contiguous bit masks are not
>> supported in Intel Cache Allocation Technology (CAT).
>>
>> Update the documentation on how to determine if sparse bit masks are
>> allowed in L2 and L3 CAT.
>>
>> Mention the file with feature support information is located in
>> the /sys/fs/resctrl/info/{resource}/ directories and enumerate what
>> are the possible outputs on file read operation.
>>
>> Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
>> Signed-off-by: Maciej Wieczor-Retman <maciej.wieczor-retman@intel.com>
>> ---
>> Changelog v2:
>> - Change bitmap naming convention to bit mask. (Reinette)
>>
>>   Documentation/arch/x86/resctrl.rst | 16 ++++++++++++----
>>   1 file changed, 12 insertions(+), 4 deletions(-)
>>
>> diff --git a/Documentation/arch/x86/resctrl.rst b/Documentation/arch/x86/resctrl.rst
>> index cb05d90111b4..4c6421e2aa31 100644
>> --- a/Documentation/arch/x86/resctrl.rst
>> +++ b/Documentation/arch/x86/resctrl.rst
>> @@ -124,6 +124,13 @@ related to allocation:
>>               "P":
>>                     Corresponding region is pseudo-locked. No
>>                     sharing allowed.
>> +"sparse_masks":
>> +        Indicates if non-contiguous 1s value in CBM is supported.
>> +
>> +            "0":
>> +                  Only contiguous 1s value in CBM is supported.
> 
> This is little confusing. How about?
> 
> Non-contiguous 1s value in CBM is not supported
> 

It is not clear to me how changing it to a double
negative reduces confusion.

Reinette