Message-ID: <8f53bb96-8213-12f1-f91c-7fb311e4c9a4@oracle.com>
Date:   Mon, 30 Jan 2023 16:07:02 +0000
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101
 Thunderbird/102.6.1
Subject: Re: [PATCH v5 10/15] perf jevents: Generate metrics and events as
 separate tables
Content-Language: en-US
To:     Ian Rogers <irogers@google.com>, Will Deacon <will@kernel.org>,
        James Clark <james.clark@arm.com>,
        Mike Leach <mike.leach@linaro.org>,
        Leo Yan <leo.yan@linaro.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Jiri Olsa <jolsa@kernel.org>,
        Namhyung Kim <namhyung@kernel.org>,
        Adrian Hunter <adrian.hunter@intel.com>,
        Kan Liang <kan.liang@linux.intel.com>,
        Kim Phillips <kim.phillips@amd.com>,
        Florian Fischer <florian.fischer@muhq.space>,
        Ravi Bangoria <ravi.bangoria@amd.com>,
        Xing Zhengjun <zhengjun.xing@linux.intel.com>,
        Rob Herring <robh@kernel.org>,
        Kang Minchul <tegongkang@gmail.com>,
        linux-arm-kernel@lists.infradead.org,
        linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org,
        Sandipan Das <sandipan.das@amd.com>,
        Jing Zhang <renyu.zj@linux.alibaba.com>,
        linuxppc-dev@lists.ozlabs.org, Kajol Jain <kjain@linux.ibm.com>
Cc:     Stephane Eranian <eranian@google.com>,
        Perry Taylor <perry.taylor@intel.com>,
        Caleb Biggers <caleb.biggers@intel.com>
References: <20230126233645.200509-1-irogers@google.com>
 <20230126233645.200509-11-irogers@google.com>
From:   John Garry <john.g.garry@oracle.com>
Organization: Oracle Corporation
In-Reply-To: <20230126233645.200509-11-irogers@google.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?TDRqRlZ0SlU2eXY4LzN1NFNGWFlmcHFXc1ZYK2RPcThZbjhaZ2Q0L3g2UExE?=
 =?utf-8?B?R0lmVk1KNldKUlN3UXpmVUEwZ2dxdUVtYzJzaG1yZHI4UjU3ZnEyUmdicTB0?=
 =?utf-8?B?bUxQaFpJb2V5enI3QkJIZUhNTXQrU1VFSFgwK1Z6a0tLRWIyMEUvY1Jqa3g4?=
 =?utf-8?B?UnNIaGF0TzhoWVlDSUJjUDdVc3pBaVRGdnFWdkVaalBsbHdma0ZqN2tJWG56?=
 =?utf-8?B?bU02TXdsczA1Qnc4K1oydjczd2RkWC9LeXBzdmFQOEdoV0NjNWNkMkI0eWpn?=
 =?utf-8?B?Z1NaMTMvY1hhTVRscHA5TjY4b3BkTCt3M1RES1R5aUZoYlplTEErMG5TVXVK?=
 =?utf-8?B?Ky9CNFh2ZmV2Yi9id2VSRW13UmNSd0NZM0VqSDBPYlBxNEM0R0xDUnlBZjU1?=
 =?utf-8?B?cXVyWm5adHNucDdtbm9KSzRvMURWZFBncHZUZ2NCNmxyUHhhZlZIdks2ektj?=
 =?utf-8?B?QXZwVFJtK1N0NElUb1hwblpJdXRGbnBqUzlSYk9uZUNvYkxMbFpaSHVqYjF1?=
 =?utf-8?B?VGpCSkhicGJkYlV6UHhzZWtQdk1VVFA1MlhkWVkxU21hRjYwN2ZHaktUaUFH?=
 =?utf-8?B?b1FKWFYzVE1haWJwYmV5MkltZ3hsbTN5R2VaNWNuV2JoSytaeEhUODVNMHBi?=
 =?utf-8?B?QS9sRU1wMlJWaVQ2RCtaSHJaa2p1RVdDWElmam9JV0lKeGhVS0VDZTMwNnZj?=
 =?utf-8?B?TE90azl1cUtwMXFSdk5uUHNGZGtONkY3dUN4d1hlaS9JZmtPYVc0dXkyQzVm?=
 =?utf-8?B?MnJkbGZYaHd4SU1CaXpnN2ZVb3BUdE5GZzVXTk0vTTd4TWpZZkx1dm9DTGdy?=
 =?utf-8?B?V1hpNDJwOXJWVVBnc3liY3k4RkcxRFZXRkh6Y3drTmxhdUNYRWVIcENyck9o?=
 =?utf-8?B?dVE4Wis0S1QyOVQ2T0J4NmRBbkQ1U0FLN2pJenZCeE5lRTFraERmZENnNUZp?=
 =?utf-8?B?N1dCU0FVdGl0Z1RPWThrU2JnaHZsVlo4L25FeFBpSzFuQ1E2SGpJNWorM1cz?=
 =?utf-8?B?MWc1YVljNXU2YTIyQytYc3ZzTXZBQWZxMDY5NGE4bHgzelJXTFJpNmFPYnJE?=
 =?utf-8?B?cC95OXA1Y2xPb1d6eEtrZm8yQUhxczE0eU0vTzkwc1AvVDNKNUhtQ0VGNnNv?=
 =?utf-8?B?dWJBWjFPd2pVWFl0aUM2OTc3MjFwQk4xVVF0dWVKNHVnNXIzbFpxQjQybHZl?=
 =?utf-8?B?Qnk0bWZ4aUdyZ2dFM082U2RsV0ZmdzFZeGNqNUNyZmxSUkV5U3hRZ1NybzRC?=
 =?utf-8?B?TW43bk1mM0xiUjRhajN6VkxSMk9kZTJ0VWJGSXN3RmhZVC8vZiszZWx6dDJN?=
 =?utf-8?B?ZmtRWHordHoxNDN0cXNiNVl5NU9KaEx0TTdqb2lyRHUrZjV4WXpUc2Nob1Fh?=
 =?utf-8?B?LzFTYlpGMnlZZnU1M21vbnRtb1FQdmx4R1hPOUV4eDA5eFpMMlppS3RCOWdu?=
 =?utf-8?B?WlFub0psNUR3NGJJRld2TDg0VWxuYXdjemd4MWpGbkNBeEpwZkZmMkdzOC9R?=
 =?utf-8?B?dlBadUc0emZ5Rk1uWGs0TURXTitBSlRHWThXamR5aUlBNUx2WmxRZm1YTFc2?=
 =?utf-8?B?TDU1d1o5cUh1QklldGUwU1F4TzZHQWdOYlFRR3pQbmVOMnQ3QVFGSGFQd2VZ?=
 =?utf-8?B?SHdEcEdaVnJmY0g3Vnh5aDBkcXBEOVpIUWloNmplQ1p6R2wxSXA2dVdaZUZt?=
 =?utf-8?B?NUxIWjNuazIxS2RQYmJpcHZXZitnWDNiR3kzNDNsRXFJRlFIVDBSR2tMaXA3?=
 =?utf-8?B?QVh1SkN3UGV1NXhraER0MVNLdkxQNUZ6WDdtUDFNVTZteDlZY1hHUjhjbHFM?=
 =?utf-8?B?OUdaR2xhWXNKbnhUNE9maG52YW1mL1BseE9UTWd1K2dmL1Fpb0ZYWVpySWtr?=
 =?utf-8?B?YmRCYWRCNklQWXl6dmtzSTN5c2NQenZsTFRlSHgwSXFzeHlVU0QyU0VRbncv?=
 =?utf-8?B?SHcraFRyRkpXZm5na0thcEpVVkRURkROdEFqZjB2NGVnMDF1ZFk3YW1xRTk2?=
 =?utf-8?B?Y2NCN05VZFV2aWRJSWlxTWZicDRSdGQxUnFVbWpLc0w0b3VYTFdDdVg0eUdy?=
 =?utf-8?B?U3ArT3JscEx2SWIyNUVBNC9jMld2UC9YdW5ia1NJK2JiRk1Db2toWnB1REtt?=
 =?utf-8?B?MDk0TzVnY2t1cURFUzZBTnlRNnJGNEx4WTRZamJQUnB0M0MvVGpkUmt2WEpn?=
 =?utf-8?B?Zmc9PQ==?=
X-MS-Exchange-AntiSpam-ExternalHop-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-ExternalHop-MessageData-0: =?utf-8?B?OHVIQ1JNRTlpREltV0ErMFpjbThDeHpSZ0pXWklqdzA4L0t2THBiZitEWmJG?=
 =?utf-8?B?dksrbUhKZHhxSHlOZzY3ckg4eXprUkd4SVNNbUVVTmNjUTFpTjBoNVViUnNp?=
 =?utf-8?B?M3dxQ24wcGxsU241d0dES1QxaW5XUWIzYVpWK2h2UzkwalZVdDRmWjhhMHh2?=
 =?utf-8?B?N3JIT1dtd3lHaDdjYkhRcWxqMFpXVHRZTDlwVVVtMm1LeEljdlUrdFdBZGpz?=
 =?utf-8?B?VlBmcWdHNGZYT2NyYUl3U0duRmhlZC9ZbnlndUNxSGtQVGdrZzFzU1FhUkNW?=
 =?utf-8?B?Um9OWEpGVjhYTk53TDVNWlZmS0MzZE5KbHF2dlRNU3dSbkxZS21rbHVDYVY2?=
 =?utf-8?B?eFhlUVhQeGFpWmNBd0gxcVpuaFQyNUtRMXl1RzE0cGJ6YnhRT05YdXJsY2lr?=
 =?utf-8?B?cW91N2dLclBqWEluTVlRM2QxSW83dHFSTC95OU9CRDJyTlJwZnE3MDd0RVd0?=
 =?utf-8?B?bk1pMlh4K0dtQnFWOCtGT1pIVjhCQ2svV3FFZ3RzRXRzdDRPV1UwUmVqZkdN?=
 =?utf-8?B?TXB6c1dIZ3VrNXpNTjVDRHJ5MXMwNjViVDZoMmVhU3c5T1YreHRUait4S3BX?=
 =?utf-8?B?bTlZL2t6RnhhTUlHdVVVQXkveG5ham9mdXhHVWhtUms2RStycFgrM1ZNN1FQ?=
 =?utf-8?B?ZVkwVDZwVkE3dXBFOFQzTys4ZFp2MnlDNkhVaVJ6UFM1UHhEbDFnOWEzMmFC?=
 =?utf-8?B?WVdGZ0R0Rlhqc1MwOGg3dTV6QktIb1NWL3pLZ0JpaUd0ODJFOTlGT09qeUZm?=
 =?utf-8?B?aHhPRERvOUpzSWh5dkFMaU5oS1F0R3B4ZTRTR0JHUW56dUFqdXdhaDl3MDBS?=
 =?utf-8?B?dVZVcDh2K3E5aVlHZTVXdDJhb3o2UzhIdFd3VXc5ZFFSRTVaL0dvUlBYVGF1?=
 =?utf-8?B?SzZvSExMU1Y3TExZZ3gwdm4xVlJaVEl2QjBNY0FYUjNFbW9TNU8rRHdneERl?=
 =?utf-8?B?aHM1MFlXaHpQWmg2VXgrNno4ZjdzN0QvSFV4eFMyVnNHWkRTOGlxRktTb21o?=
 =?utf-8?B?K0MzaFd1bHBhQVNQOTVlZlJnNHNHeGFML2RqcWhuUUlJWFNGTFJOVnhxOEpZ?=
 =?utf-8?B?ZUU1dUtpdm5rcnIwSE5kb28va3Q2VWVRaEkxTlB2M3pzSUhkbDY2MHVxK0Jo?=
 =?utf-8?B?bW1pZFh3OEswMjIyOVNhNnY0NVhJa2QwQm85RCtSOUVCa2Y1dlh2YTBWaXQy?=
 =?utf-8?B?Q2dxclJwQVkrUk5EdnF4NlltOHQycWcxODQxbTY3bk42N0hiMG95NEtOWHRD?=
 =?utf-8?B?VlNBSmk3YU5idlJ6VWRmcjc0MHF0WGJSS2xxRzY3enhocnZiYTMzQXU4Wllh?=
 =?utf-8?B?QTd3dDFiaDNaakJibEdVOTl0bWZ2UEF0bGlFMm9qWmNKNUxIOWFzWFFYNUlZ?=
 =?utf-8?B?Y1hxM2hwQ0lEVlplUUhqV2txZEZzbno5eFo1WkQrVHdBdDBaUTR5TUdCOVBD?=
 =?utf-8?B?dXQwWWFWVGcybmxJN05PZlg4eHExdTkva0tEY0QrOTRTbWZFRGZ0dDFnSWxz?=
 =?utf-8?B?bHVuVmI3Qm1neFBPZ1VOU2VDTE9KcFN4VE9aNHBRdjdnRFJDU2ZubC9mNm96?=
 =?utf-8?B?ODM3cWU0TU5wVUhQaEo0UzAxclRvdEhNSks1TG1xUU5BNmczY2hLTmdobzQ1?=
 =?utf-8?B?blZld2t2MTN3SWpheTZkZmxEdUtBNWl5MVVHREVscXJrd2JwTi96YjZSNkhW?=
 =?utf-8?Q?yxZbsOyGXEF1R/64llOh?=
X-OriginatorOrg: oracle.com
X-MS-Exchange-CrossTenant-Network-Message-Id: b8afb509-0737-4aca-3e8c-08db02dc0a67
X-MS-Exchange-CrossTenant-AuthSource: DM6PR10MB4313.namprd10.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 30 Jan 2023 16:07:09.6166
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 4e2c6054-71cb-48f1-bd6c-3a9705aca71b
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: 5/elZhv+qGI3rl7xkYBk6tsFUxwBsAtFwAC7geJzaxaDirh7Gnv34NtO1gdmHoD4L2YOaQ24OJOAGHCk/iA0Qw==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: SJ2PR10MB6963
X-Proofpoint-Virus-Version: vendor=baseguard
 engine=ICAP:2.0.219,Aquarius:18.0.930,Hydra:6.0.562,FMLib:17.11.122.1
 definitions=2023-01-30_15,2023-01-30_01,2022-06-22_01
X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 bulkscore=0 malwarescore=0
 suspectscore=0 adultscore=0 mlxscore=0 phishscore=0 mlxlogscore=999
 spamscore=0 classifier=spam adjust=0 reason=mlx scancount=1
 engine=8.12.0-2212070000 definitions=main-2301300156
X-Proofpoint-ORIG-GUID: 643qEshZa01PC0qxTuQ55oAntMiwXRiz
X-Proofpoint-GUID: 643qEshZa01PC0qxTuQ55oAntMiwXRiz
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On 26/01/2023 23:36, Ian Rogers wrote:
> @@ -660,7 +763,29 @@ const struct pmu_events_table *perf_pmu__find_events_table(struct perf_pmu *pmu)
>   
>   const struct pmu_metrics_table *perf_pmu__find_metrics_table(struct perf_pmu *pmu)
>   {
> -        return (struct pmu_metrics_table *)perf_pmu__find_events_table(pmu);
> +        const struct pmu_metrics_table *table = NULL;
> +        char *cpuid = perf_pmu__getcpuid(pmu);
> +        int i;
> +
> +        /* on some platforms which uses cpus map, cpuid can be NULL for
> +         * PMUs other than CORE PMUs.
> +         */
> +        if (!cpuid)
> +                return NULL;
> +
> +        i = 0;
> +        for (;;) {
> +                const struct pmu_events_map *map = &pmu_events_map[i++];
> +                if (!map->arch)
> +                        break;
> +
> +                if (!strcmp_cpuid_str(map->cpuid, cpuid)) {
> +                        table = &map->metric_table;
> +                        break;
> +                }
> +        }
> +        free(cpuid);
> +        return table;
>   }

This is almost identical to generated perf_pmu__find_events_table(), 
except we return a pmu_metrics_table * (instead of a pmu_events_table *) 
and also return the metric table member (instead of event table). But 
the definitions are:

/* Struct used to make the PMU event table implementation opaque to 
callers. */
struct pmu_events_table {
         const struct compact_pmu_event *entries;
         size_t length;
};

/* Struct used to make the PMU metric table implementation opaque to 
callers. */
struct pmu_metrics_table {
         const struct compact_pmu_event *entries;
         size_t length;
};

Those structs are defined to be the same thing, so I am failing to see 
the point in a) separate structure types b) why so much duplication

As for b), I know that they are generated and the python code may be 
simpler this way (is it?), but still...

Thanks,
John