Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Song Liu <songliubraving@fb.com>
To:     Jiri Olsa <jolsa@redhat.com>
CC:     Song Liu <song@kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Kernel Team <Kernel-team@fb.com>,
        "acme@kernel.org" <acme@kernel.org>,
        "acme@redhat.com" <acme@redhat.com>,
        "namhyung@kernel.org" <namhyung@kernel.org>,
        "jolsa@kernel.org" <jolsa@kernel.org>
Subject: Re: [PATCH v3 3/4] perf-stat: introduce config
 stat.bpf-counter-events
Thread-Topic: [PATCH v3 3/4] perf-stat: introduce config
 stat.bpf-counter-events
Thread-Index: AQHXMw3DyOxUaVUpS0ODNNUcJNtKe6q76eYAgABkwYA=
Date:   Mon, 19 Apr 2021 20:27:14 +0000
Message-ID: <C55B43CE-0909-4322-89DB-143A300871A6@fb.com>
References: <20210416221325.2373497-1-song@kernel.org>
 <20210416221325.2373497-4-song@kernel.org> <YH2THG9zES3rjvEs@krava>
In-Reply-To: <YH2THG9zES3rjvEs@krava>
Accept-Language: en-US
Content-Language: en-US
Content-Type: text/plain; charset="us-ascii"
Content-ID: <BE992C2EA7F66E4693749C48E2866D14@namprd15.prod.outlook.com>
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
X-MS-Exchange-CrossTenant-Network-Message-Id: a1e4035f-e799-4c25-cc94-08d9037184b1
X-MS-Exchange-CrossTenant-originalarrivaltime: 19 Apr 2021 20:27:14.1738
 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: 8ae927fe-1255-47a7-a2af-5f3a069daaa2
X-MS-Exchange-CrossTenant-mailboxtype: HOSTED
X-MS-Exchange-CrossTenant-userprincipalname: mh6F1/eAqdMNh1Evyd6icA38nyT5PHeprc6mEPDDJ2/eizwngyMH9ld9cdZqZPmjDkAUorLHz8GWmVJ3rWIDLQ==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: BY3PR15MB4978
X-OriginatorOrg: fb.com
X-Proofpoint-ORIG-GUID: c96VY2J4byrgd768LwrO4mo1PCYUz0pO
X-Proofpoint-GUID: c96VY2J4byrgd768LwrO4mo1PCYUz0pO
X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.391,18.0.761
 definitions=2021-04-19_11:2021-04-19,2021-04-19 signatures=0
X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 suspectscore=0
 lowpriorityscore=0 mlxscore=0 clxscore=1015 impostorscore=0
 mlxlogscore=999 phishscore=0 adultscore=0 bulkscore=0 priorityscore=1501
 spamscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1
 engine=8.12.0-2104060000 definitions=main-2104190140
X-FB-Internal: deliver
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org


> On Apr 19, 2021, at 7:26 AM, Jiri Olsa <jolsa@redhat.com> wrote:
>=20
> On Fri, Apr 16, 2021 at 03:13:24PM -0700, Song Liu wrote:
>=20
> SNIP
>=20
>> +/*
>> + * Returns:
>> + *     0   if all events use BPF;
>> + *     1   if some events do NOT use BPF;
>> + *     < 0 on errors;
>> + */
>> static int read_bpf_map_counters(void)
>> {
>> +	bool has_none_bpf_events =3D false;
>> 	struct evsel *counter;
>> 	int err;
>>=20
>> 	evlist__for_each_entry(evsel_list, counter) {
>> +		if (!evsel__is_bpf(counter)) {
>> +			has_none_bpf_events =3D true;
>> +			continue;
>> +		}
>> 		err =3D bpf_counter__read(counter);
>> 		if (err)
>> 			return err;
>> 	}
>> -	return 0;
>> +	return has_none_bpf_events ? 1 : 0;
>> }
>>=20
>> static void read_counters(struct timespec *rs)
>> @@ -442,9 +455,10 @@ static void read_counters(struct timespec *rs)
>> 	int err;
>>=20
>> 	if (!stat_config.stop_read_counter) {
>> -		if (target__has_bpf(&target))
>> -			err =3D read_bpf_map_counters();
>> -		else
>> +		err =3D read_bpf_map_counters();
>> +		if (err < 0)
>> +			return;
>> +		if (err)
>> 			err =3D read_affinity_counters(rs);
>=20
> this part is confusing for me.. I understand we don't want to enter
> read_affinity_counters when there's no bpf counter, so we don't set
> affinities in vain.. but there must be better way ;-)
>=20
>> diff --git a/tools/perf/util/bpf_counter.c b/tools/perf/util/bpf_counter=
.c
>> index 5de991ab46af9..3189b63714371 100644
>> --- a/tools/perf/util/bpf_counter.c
>> +++ b/tools/perf/util/bpf_counter.c
>> @@ -792,6 +792,8 @@ int bpf_counter__load(struct evsel *evsel, struct ta=
rget *target)
>> 		evsel->bpf_counter_ops =3D &bpf_program_profiler_ops;
>> 	else if (target->use_bpf)
>> 		evsel->bpf_counter_ops =3D &bperf_ops;
>> +	else if (evsel__match_bpf_counter_events(evsel->name))
>> +		evsel->bpf_counter_ops =3D &bperf_ops;
>=20
> please put this with the target->use_bpf check,
> it seems like it's another thing

Thanks for the review. Fixing these in v4.=20

Song