From: Song Liu <songliubraving@fb.com>
To: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Netdev <netdev@vger.kernel.org>,
linux-kernel <linux-kernel@vger.kernel.org>,
"ast@kernel.org" <ast@kernel.org>,
"daniel@iogearbox.net" <daniel@iogearbox.net>,
Kernel Team <Kernel-team@fb.com>,
"peterz@infradead.org" <peterz@infradead.org>,
"jolsa@kernel.org" <jolsa@kernel.org>,
"namhyung@kernel.org" <namhyung@kernel.org>
Subject: Re: [PATCH v2 perf,bpf 11/11] perf, bpf: save information about short living bpf programs
Date: Fri, 15 Feb 2019 18:13:35 +0000 [thread overview]
Message-ID: <D4559155-4993-4319-81C9-AC4ADDDAE3B6@fb.com> (raw)
In-Reply-To: <20190215180916.GJ5784@redhat.com>
> On Feb 15, 2019, at 10:09 AM, Arnaldo Carvalho de Melo <acme@redhat.com> wrote:
>
> Em Fri, Feb 15, 2019 at 05:13:01PM +0000, Song Liu escreveu:
>>> On Feb 15, 2019, at 6:41 AM, Arnaldo Carvalho de Melo <acme@redhat.com> wrote:
>>> Em Thu, Feb 14, 2019 at 04:00:45PM -0800, Song Liu escreveu:
>>>> +pthread_t poll_thread;
>>>> +
>>>> +int bpf_event__start_polling_thread(struct bpf_event_poll_args *args)
>>>> +{
>>>> + struct perf_evsel *counter;
>>>> +
>>>> + args->evlist = perf_evlist__new();
>>>> +
>>>> + if (args->evlist == NULL)
>>>> + return -1;
>>>> +
>>>> + if (perf_evlist__create_maps(args->evlist, args->target))
>>> goto out_delete_evlist;
>>>> +
>>>> + if (perf_evlist__add_bpf_tracker(args->evlist))
>>> goto out_delete_evlist;
>>>> +
>>>> + evlist__for_each_entry(args->evlist, counter) {
>>>> + if (perf_evsel__open(counter, args->evlist->cpus,
>>>> + args->evlist->threads) < 0)
>>> goto out_delete_evlist;
>>>> + }
>>>> +
>>>> + if (perf_evlist__mmap(args->evlist, UINT_MAX))
>>> goto out_delete_evlist;
>>>> +
>>>> + evlist__for_each_entry(args->evlist, counter) {
>>>> + if (perf_evsel__enable(counter))
>>> goto out_delete_evlist;
>>>> + }
>>>> +
>>>> + if (pthread_create(&poll_thread, NULL, bpf_poll_thread, args))
>>> goto out_delete_evlist;
>>>> +
>>>> + return 0;
>>> out_delete_evlist:
>>> perf_evlist__delete(args->evlist);
>>> args->evlist = NULL;
>
> Have you seen the error handling suggestion above?
Yes! I will include these changes, as always. :)
>
>>>> +int perf_evlist__add_bpf_tracker(struct perf_evlist *evlist)
>>>> +{
>>>> + struct perf_event_attr attr = {
>>>> + .type = PERF_TYPE_SOFTWARE,
>>>> + .config = PERF_COUNT_SW_DUMMY,
>>>> + .watermark = 1,
>>>> + .bpf_event = 1,
>>>> + .wakeup_watermark = 1,
>>>> + .size = sizeof(attr), /* to capture ABI version */
>>>> + };
>>>> + struct perf_evsel *evsel = perf_evsel__new_idx(&attr,
>>>> + evlist->nr_entries);
>>>> +
>>>> + if (evsel == NULL)
>>>> + return -ENOMEM;
>>>> +
>>>> + perf_evlist__add(evlist, evsel);
>
>>> You could use:
>
>>> struct perf_evlist *evlist = perf_evlist__new_dummy();
>>> if (evlist != NULL) {
>>> struct perf_evsel *evsel == perf_evlist__first(evlist);
>>> evsel->attr.bpf_event = evsel->attr.watermark = evsel->attr.wakeup_watermark = 1;
>>> return 0;
>>> }
>>> return -1;
>
>> This looks cleaner. Let me fix in next version.
>
>>> Because in this case all you'll have in this evlist is the bpf tracker,
>>> right? The add_bpf_tracker would be handy if we would want to have a
>>> pre-existing evlist with some other events and wanted to add a bpf
>>> tracker, no?
>
>> I think all we need is a side-band evlist instead of the main evlist. May
>> be we should call it side-band evlist, and make it more generic?
>
> Sure, you could for instance have something like:
>
> struct perf_event_attr attr = {
> .watermark = 1,
> .bpf_event = 1,
> .wakeup_watermark = 1,
> }
> struct perf_evlist *evlist = perf_evlist__new_side_band(&attr);
>
>
> And the other details will be set by it, i.e. the .config
>
> .type = PERF_TYPE_SOFTWARE,
> .config = PERF_COUNT_SW_DUMMY,
> .size = sizeof(attr), /* to capture ABI version */
>
> And the idx arg.
>
> - Arnaldo
This looks good. Let me revise the patch in that direction.
Thanks,
Song
prev parent reply other threads:[~2019-02-15 18:14 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-14 23:56 [PATCH v2 perf,bpf 00/11] perf annotation of BPF programs Song Liu
2019-02-14 23:58 ` [PATCH v2 perf,bpf 01/11] perf, bpf: consider events with attr.bpf_event as side-band events Song Liu
2019-02-15 14:14 ` Arnaldo Carvalho de Melo
2019-02-15 17:02 ` Song Liu
2019-02-15 18:04 ` Arnaldo Carvalho de Melo
2019-02-15 0:00 ` [PATCH v2 perf,bpf 02/11] bpf: libbpf: introduce bpf_program__get_prog_info_linear() Song Liu
2019-02-15 0:00 ` [PATCH v2 perf,bpf 03/11] bpf: bpftool: use bpf_program__get_prog_info_linear() in prog.c:do_dump() Song Liu
2019-02-15 0:00 ` [PATCH v2 perf,bpf 04/11] perf, bpf: synthesize bpf events with bpf_program__get_prog_info_linear() Song Liu
2019-02-15 0:00 ` [PATCH v2 perf,bpf 05/11] perf, bpf: save bpf_prog_info in a rbtree in perf_env Song Liu
2019-02-15 14:21 ` Arnaldo Carvalho de Melo
2019-02-15 17:04 ` Song Liu
2019-02-15 0:00 ` [PATCH v2 perf,bpf 06/11] perf, bpf: save bpf_prog_info information as headers to perf.data Song Liu
2019-02-15 0:00 ` [PATCH v2 perf,bpf 07/11] perf, bpf: save btf in a rbtree in perf_env Song Liu
2019-02-15 14:30 ` Arnaldo Carvalho de Melo
2019-02-15 0:00 ` [PATCH v2 perf,bpf 08/11] perf, bpf: save btf information as headers to perf.data Song Liu
2019-02-15 14:26 ` Arnaldo Carvalho de Melo
2019-02-15 17:25 ` Song Liu
2019-02-15 17:40 ` Arnaldo Carvalho de Melo
2019-02-15 17:47 ` Song Liu
2019-02-15 18:20 ` Arnaldo Carvalho de Melo
2019-02-15 18:59 ` Song Liu
2019-02-15 0:00 ` [PATCH v2 perf,bpf 09/11] perf-top: add option --bpf-event Song Liu
2019-02-15 14:27 ` Arnaldo Carvalho de Melo
2019-02-15 17:06 ` Song Liu
2019-02-15 18:05 ` Arnaldo Carvalho de Melo
2019-02-15 0:00 ` [PATCH v2 perf,bpf 10/11] perf, bpf: enable annotation of bpf program Song Liu
2019-02-15 0:00 ` [PATCH v2 perf,bpf 11/11] perf, bpf: save information about short living bpf programs Song Liu
2019-02-15 14:41 ` Arnaldo Carvalho de Melo
2019-02-15 17:13 ` Song Liu
2019-02-15 18:09 ` Arnaldo Carvalho de Melo
2019-02-15 18:13 ` Song Liu [this message]
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