Received-SPF: pass (google.com: domain of linux-kernel+bounces-77788-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.80.249 as permitted sender) client-ip=147.75.80.249;
Message-ID: <9eeb2273-9690-8f71-4f3f-595310d53600@amd.com>
Date: Fri, 23 Feb 2024 10:57:22 +0530
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101
 Thunderbird/102.10.0
Subject: Re: [PATCH v4 1/4] perf/core: Rework forwarding of {task|cpu}-clock
 events
To: Pengfei Xu <pengfei.xu@intel.com>
Cc: peterz@infradead.org, namhyung@kernel.org, eranian@google.com,
 acme@kernel.org, mark.rutland@arm.com, jolsa@kernel.org, irogers@google.com,
 bp@alien8.de, kan.liang@linux.intel.com, adrian.hunter@intel.com,
 maddy@linux.ibm.com, x86@kernel.org, linux-perf-users@vger.kernel.org,
 linux-kernel@vger.kernel.org, sandipan.das@amd.com, ananth.narayan@amd.com,
 santosh.shukla@amd.com, lkp@intel.com, Ravi Bangoria <ravi.bangoria@amd.com>
References: <20230504110003.2548-1-ravi.bangoria@amd.com>
 <20230504110003.2548-2-ravi.bangoria@amd.com>
 <ZdRluZx3fy0xx78D@xpf.sh.intel.com>
Content-Language: en-US
From: Ravi Bangoria <ravi.bangoria@amd.com>
In-Reply-To: <ZdRluZx3fy0xx78D@xpf.sh.intel.com>
Content-Type: text/plain; charset=UTF-8
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?dzl5SWNGYWtNQUZrVjQ0azBpRHVhSVRHNSt5SVBUSERudjZNVGw1eWVnc1Zq?=
 =?utf-8?B?cVVvbm1wakZzdDV6bFBUMTV5WE01aWVqK2c2QllLZ3pQVVhWU085RHRPSmJN?=
 =?utf-8?B?V3RWZmxXNnV1cUVCY2RJUUw4REI0ZHRab1hOVTkxaVFNSzFGTE5Tc0JWN3Ix?=
 =?utf-8?B?enplTDliMENwalU3Ry8zVTFuTkRNSHJMa2h3aTEzU3QzRFQxN2RWbHZqQUVj?=
 =?utf-8?B?c1pPVEdXYjN3YTc3RFRvMnA1aWtkR0Q0cDFDU2Y4QXlwaSs1Vjk1NWsvQUxx?=
 =?utf-8?B?OWZ6UnNNRkJib3liVXplc2dxUXlza25pVnBVVGRCTGxMZHdTTjR5ZFZIR2N2?=
 =?utf-8?B?YUVWaGpDbVBDdHN4ZkducVp2ekI2OFp3cWlMSXNmMyswcTNEUFZYa1grWm5x?=
 =?utf-8?B?ZDZ2QnJ5TlJ1ZFJkNWd2ajNudlhPQlZCc3Q0bXhEZ3JKd1Q0TmdkK2tLQmNk?=
 =?utf-8?B?a0ExLy9LZ2xzbk9zZzYvYU1nYVpEWExXWm52bEJDSDJ3U2dMK0kyU2lFY0Iy?=
 =?utf-8?B?Wkd6ZG5wb0Z3d1RES0NZZmNpY3BpdGlWZ2svQWNTTFRHR0NsZVA5QTIvTGlR?=
 =?utf-8?B?V2syRzgyTWFackMvb1dQRk1IRHlqUXJYRVk3alhwU0xwMkp5UXpLWlBSRWxw?=
 =?utf-8?B?aExvQVd2TGlsVWJwR2lyR2s2aVRpNitIOGx5OHkyWk9JUGNjMGg2Qnd3aDU5?=
 =?utf-8?B?dk4vb2lYcFFVL3FFelNvUFJQQlN3OVRPTHBPU3NMUXlyNWdXTG9EREIzVWVl?=
 =?utf-8?B?ZE5VN0wweHZ5RVZiNThORDgySnc0Tm84SU1EQjhnRzZNTjlRRkJhQTRGWVR5?=
 =?utf-8?B?cVhYaHlmMmRZWFR2aS8vbFNHNEZ4c3JzV3hMcGJvd0d5QjZlOXdHbEVGQzk0?=
 =?utf-8?B?VWxyWlFzTWxMQU5vRU9RUmkraVM2VjRqdzZPcy9wZWdlbnZqZ3FuZTlWei9Y?=
 =?utf-8?B?OU0zRTVtUlBmQk14NVBWeW1ybkJnNEZmYzdEWDI0dHgzOXJGZ25RVnBtYi8z?=
 =?utf-8?B?RFo4ZEdvaER5MVp2cWRGOFlmWVBDV2lpdkFNZzVyRnRPYnQ1M25zN21YTkU5?=
 =?utf-8?B?NnVObVJkNTRlWGpEN1FnVmdJQWpaOW5TUGxhcUFrekhzZm5McldsUXBXQ0Z2?=
 =?utf-8?B?RHQ0Qnlmbmt3by9kajZXK1dIZVllYXFVdjZrSUhEdmVkK0RuRjJ0amp5UExW?=
 =?utf-8?B?RnFZNGhzMFJpTkdyTFNad1Y2MlgvZWZUelE4clFWRnB5cDhhNGVYT0N0cHVK?=
 =?utf-8?B?MWVxbnZWbkNPUlptUThhVGZ2R1YwbmVkOHc0dVdLSTI3T21JZW04bDR2d1ZT?=
 =?utf-8?B?V0ZVYzRsRlY3WnF4OFROZnpudHR6SkJaSi8wRFhENnRMSTFTT0taNDRyUFRJ?=
 =?utf-8?B?MW5iN0VXb1gvYms4TUd6bTQ5b25kVlBWSkVZU1FGU1dVRitkMTJPS3JQZllH?=
 =?utf-8?B?N1JwZTEyb0hWZ2h5Vk13ekc1TzRVWjZXZm1tZytLR3RGU2p4U3hCcVB3eERn?=
 =?utf-8?B?ZUs2L05QRFQ2WGNpaW9sT2R3cjU3elQwVC9hOWJ2WmJRTFo2SUR2bS9TKzhx?=
 =?utf-8?B?a3gwcCt0aGlUSHhhZ3VsK3dkbU9BcXhUQ2ZMYk9VbEYzNXlXSXQ1dFdIcUJh?=
 =?utf-8?B?N3k2SXNWc2xmenljMHNIb1BSd3QrL2Q5UUFFaE1CK2ZPT0NRWC9JTloyRzhn?=
 =?utf-8?B?VE83ajFQaWxpcCtDbVFmdE5oYUFBaVdUeFE3ZW0vSXRmUG5oREZDNk5QNFpF?=
 =?utf-8?B?ZGlSZGFyS2toc3pwM1FZcGt2bVZEdVdFN0E2cXY2QXZrclE2bnZIYWF2YklO?=
 =?utf-8?B?bytpMmIybGtuQ3JyYzVZZ2t1dkc3SE9pQVVtd2M4WVNUb1pMNTV5MWZqMHFN?=
 =?utf-8?B?VmVwNnpGdk5DUEJpUFpKU1lZQVQ0MytLWk9hNjZkTVZXbncyUDZjd1VqMjhN?=
 =?utf-8?B?Qk1LSDFHZUR1em1iYlVuU2hiRTJ5K1R1WW5zd1VCNy91Vis2NjJvbWhxWk1P?=
 =?utf-8?B?S2Y0RHFtK1dQbEJ4NlI2ZTlTeWFpUzNpZVA1dGU2MW1VZVJUWEJzUWpwUWVD?=
 =?utf-8?B?TEd5UmVxRGtNQXg0dWRCRkR5dkliS3dxdEtxSkFrTjJTK1BWaEJXeW53WFpo?=
 =?utf-8?Q?nRGJaFnJjMwtR5reinclLaN3h?=
X-OriginatorOrg: amd.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 744797a0-c3df-46c4-52c7-08dc34304237
X-MS-Exchange-CrossTenant-AuthSource: PH7PR12MB6588.namprd12.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 23 Feb 2024 05:28:25.7136
 (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: jAtC8ZlTrMrMs/jR8UUMVZ+URsrnhcdZaWacbZPoqEXpmwc7g+L4w404owlnOLK6krsHj3J/uA1aaEKlK0QoMg==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: PH7PR12MB7454

Hi Pengfei,

On 20-Feb-24 2:11 PM, Pengfei Xu wrote:
> Hi Ravi Bangoria,
> 
> On 2023-05-04 at 16:30:00 +0530, Ravi Bangoria wrote:
>> Currently, PERF_TYPE_SOFTWARE is treated specially since task-clock and
>> cpu-clock events are interfaced through it but internally gets forwarded
>> to their own pmus.
>>
>> Rework this by overwriting event->attr.type in perf_swevent_init() which
>> will cause perf_init_event() to retry with updated type and event will
>> automatically get forwarded to right pmu. With the change, SW pmu no
>> longer needs to be treated specially and can be included in 'pmu_idr'
>> list.
>>
>> Suggested-by: Peter Zijlstra <peterz@infradead.org>
>> Signed-off-by: Ravi Bangoria <ravi.bangoria@amd.com>
>> ---
>>  include/linux/perf_event.h | 10 +++++
>>  kernel/events/core.c       | 77 ++++++++++++++++++++------------------
>>  2 files changed, 51 insertions(+), 36 deletions(-)
> 
> Greeting!
> There is task hung in perf_tp_event_init in v6.8-rc4 in guest.

Thanks for the bug report. I'm able to reproduce it. Will try to spend
more time to rootcause it.

Thanks,
Ravi