Received-SPF: pass (google.com: domain of linux-kernel+bounces-206511-linux.lists.archive=gmail.com@vger.kernel.org designates 139.178.88.99 as permitted sender) client-ip=139.178.88.99;
Message-ID: <03ab405b-d7e4-4c35-8a3f-546ffd590954@intel.com>
Date: Fri, 7 Jun 2024 09:49:30 -0700
User-Agent: Mozilla Thunderbird
Subject: Re: [PATCH v19 16/20] x86/resctrl: Make resctrl_arch_rmid_read()
 handle sum over domains
To: Tony Luck <tony.luck@intel.com>
CC: Fenghua Yu <fenghua.yu@intel.com>, Maciej Wieczor-Retman
	<maciej.wieczor-retman@intel.com>, Peter Newman <peternewman@google.com>,
	James Morse <james.morse@arm.com>, Babu Moger <babu.moger@amd.com>, "Drew
 Fustini" <dfustini@baylibre.com>, Dave Martin <Dave.Martin@arm.com>,
	<x86@kernel.org>, <linux-kernel@vger.kernel.org>, <patches@lists.linux.dev>
References: <20240528222006.58283-1-tony.luck@intel.com>
 <20240528222006.58283-17-tony.luck@intel.com>
 <9818c304-9056-4d79-acbe-2b35cb847ecd@intel.com>
 <Zl5OmVWFpBtA509j@agluck-desk3.sc.intel.com>
From: Reinette Chatre <reinette.chatre@intel.com>
Content-Language: en-US
In-Reply-To: <Zl5OmVWFpBtA509j@agluck-desk3.sc.intel.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?Q0pDRTMwcDVzUFh4bGJnanJlSFZCMmFuaTVMSjNBelNRVVFRcDBoa3Y5VW5Q?=
 =?utf-8?B?VjI3d3dWMG14UnR0UlE2bjJwRFdFN3NMUmhHTjVTZFhnUDdWM3JxZGZhSVA2?=
 =?utf-8?B?WjdmQ0diZVR2SjlXL2pyS3JsMzZKSDJlL2gvQy9LMXNWb1VaLy9YM3poQ3dY?=
 =?utf-8?B?cWxEcHJwTHZFSVllU3czTmhIc0NDUHVUZWp5c0F2WXhJQTMvWnBZWmo0MmVr?=
 =?utf-8?B?MnNjRmFSRys4cjlyQ1VieEozZmpEQ3k3RUF6ZFBQaEpxczNMNGtaSlRtOGtU?=
 =?utf-8?B?SG1SVnlzUXFnWWQyTVdyU2Y0VU84WmM4bkVRc2ZRQlFEWVRoV0dqbFp1RGs3?=
 =?utf-8?B?U1Q3S2VndWpqQmlQZzZQcFFpQW9pbEZXbTU0em1GcGlEVmJ2UXhjWmpJZHRV?=
 =?utf-8?B?V2laTUUwWHdqUWZBdGo0SEVIVU9Qdk9ZcmlRc1J4d3ZXdmNvWEp0RTFRNFdT?=
 =?utf-8?B?OEVXQnJWdks2ZDNwVVE5eEwxdXVmSmJzUVRKUzBTUmFJeXhXK0tyZXdtTlVn?=
 =?utf-8?B?WHpDRjZPQUhlRFoxbmFiSGhaZ2JlMVphWUVidEVyQVR0U0t3K0NlNGhlQmwz?=
 =?utf-8?B?SDFjWkFOM3c1NnBoU3M2QnkyVG95YzZwNHl3dkJyL2xsazBQNHRWMHc4NUNJ?=
 =?utf-8?B?VFZxTFA5VmlkaitXZXlWclBkSW40all3M0dTaFVtZWE3M1BpSS9DUCtOSUlh?=
 =?utf-8?B?NXVOUTZxTFcvb3Jpa0w5SXFTNHVkZ0E3Z21NdTJqVnFqcllQNFJBM2t2dlZu?=
 =?utf-8?B?eW1YYld5OG1YM3ZHdUlmeWJvREJtOTUxS2lhUWVaMjZuVFdCbEltNTdMcDh0?=
 =?utf-8?B?ZTIzSUc1RURoZ01VdldlbTdTUWVnN1d2cXBJcitsYnEvV1BHRHYrQlRjT1pE?=
 =?utf-8?B?UFlwTXkxYjVJTUJiMThweGFCYjRuY3c2YUV1bmxNSFRlM3R2b3hsOUg3eHpm?=
 =?utf-8?B?V3RQdSs1c3c2N3J6ZWltVUJUajBvS3FhQzZXTlNseHpIS296bnU5UGQraCtJ?=
 =?utf-8?B?WTd5RjJrTHcremk4NXRlcEcrbHU4RUgzcU5Gd2FzLzN4NDJiK0ovVHZXQWZt?=
 =?utf-8?B?TmVwVXlhbnBCK3Awai9pNHNLQWpVaDMxcU5WUTdpVzFVVFlUU2FJQXpQcmta?=
 =?utf-8?B?YXNsNlBoaWhXK3VZM1RCTjBOdXd5aHF6RlZHaVZ1SDlwdGUrMDlwS05kN1Ns?=
 =?utf-8?B?TzR3OGNqa0tzZHkxdTQ5UGx4a2pUSnVkblJZR3hSdWhHZEtJVFRPOTlUeGFB?=
 =?utf-8?B?WEVKb2FjSkdud0MzdElJWkcwODNucmxhV29LVXlFaTJKK0ovVDZXaW9hSVkv?=
 =?utf-8?B?QVVvamNhcnZFazMzeTRacTdVYXR6eTZNWTVTZXFTWEhFVWpvcGZhZlNWaHg2?=
 =?utf-8?B?eGFYN2RrUlBGZnZ3a2NaRTFLSzdya0R2a2ZHQlltN2FaQ2JDZ3pzUlpySnhl?=
 =?utf-8?B?NDdWY0VYZGQ4K1RCdUU5WWxFdGQ4RGZpdW9iM2VCYncwZVJodUQ0VXBkMFVo?=
 =?utf-8?B?UXl5RnEzWjRJU043VG82QUhVc1VCdEc4TXdCdHFjWjRmc3hhZ1BSNVgyNDJD?=
 =?utf-8?B?UHpGd1VzRUpIRGhCQU9pTjI2aE5mRldLTEg4RWVKOE1BTWNZSnF0bXY2VlBw?=
 =?utf-8?B?b1JtZko0TjBvQmZvaVFnTElWMkk1ZEpFYWV6OGIyWVZTblQ2MHhQclVJRVFP?=
 =?utf-8?B?VkVyOTdoc3M3Z01HS2JBTjk0Mkc2d1htTkw4SVV6L3BDRjh0ckVPaldrcS9y?=
 =?utf-8?B?c1VLTVFTTzZsUnFVN0loR3BncFpyZFE0dzJTVFpPSnVURmNSNGFMMUR0K3E4?=
 =?utf-8?B?ZVYycW4yVlU4NVplOXRFaFlwdE9RZDRlaVV0ekpxN3N3SnM4dS93NVBrb0Ja?=
 =?utf-8?B?NEprdmtWNDdRZWN2RnBoeDZSKzBkSW1seS9zQnJLa1ZiZ2Y1aUZCdlpnVUF3?=
 =?utf-8?B?RXRSZHRhd2VjeWMvTEprL2Q2Y1lvOTZhYk9hNWwwTkpNYlBtT0RFeUluZ0Jh?=
 =?utf-8?B?RmU5ZW9SRmNIVzM3eWI3dHB4RXRJYXBTck9UMmd0djA5MFdJMDNnTFowN2hu?=
 =?utf-8?B?dzFrL0NKVFd5RXRNQ0JGWHNiVSt1SWpDTVNObE9EUStpZ293Y3R5dmNLdndK?=
 =?utf-8?B?Z2FSUXpaTkd4czhBQ3NBaWdkZG1nTHdaNldQV3JRQUxhMnFmcDdKNjVZZTQ1?=
 =?utf-8?B?K1E9PQ==?=
X-MS-Exchange-CrossTenant-Network-Message-Id: 6813b900-73f8-44b1-798f-08dc8711ce7f
X-MS-Exchange-CrossTenant-AuthSource: SJ2PR11MB7573.namprd11.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 07 Jun 2024 16:49:32.9612
 (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: uNZ7NdjZRyK0G19sPMwhrN2+ehT2qZiT9fOHOVNsW4P53njARHgUeOJumC8PIEWKV1zwZ3sQAwTOH1dUVdir635oWL8L2PaUsqsfU0xskro=
X-MS-Exchange-Transport-CrossTenantHeadersStamped: IA1PR11MB6146
X-OriginatorOrg: intel.com

Hi Tony,

On 6/3/24 4:15 PM, Tony Luck wrote:
> On Thu, May 30, 2024 at 01:24:57PM -0700, Reinette Chatre wrote:
>> On 5/28/24 3:20 PM, Tony Luck wrote:
...

>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +int resctrl_arch_rmid_read(struct rdt_resource *r, struct rdt_mon_domain *d,
>>> +			   u32 unused, u32 rmid, enum resctrl_event_id eventid,
>>> +			   u64 *val, bool sum, struct cacheinfo *ci, void *ignored)
>>
>> This is not architecture specific code.
> 
> Can you explain further? I've dropped the "sum" argument. As you pointed
> out elsewhere this can be inferred from "d == NULL".  But I do need the
> cacheinfo information in resctrl_arch_rmid_read() to:
> 1) determine which domains to sum (those that match ci->id).
> 2) sanity check code is executing on a CPU in ci->shared_cpu_map.
> 

"resctrl_arch_*" is the prefix of functions needed to be implemented
by every architecture. As I understand there is nothing architecture
specific about what this function does and every architecture's function
would thus end up looking identical. I expected the cacheinfo
information to be available from all architectures. If this is not
the case then it does not belong in struct rdt_mon_domain but should
instead be moved to struct rdt_hw_mon_domain ... but since cacheinfo
has already made its way into the filesystem code it is not clear
to me how you envision the arch/fs split.

Reinette