Messages in this thread | | | From | Stephane Eranian <> | Date | Fri, 23 Jul 2021 09:07:35 -0700 | Subject | Re: [PATCH 2/2] perf record: Add --synth option |
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On Thu, Jul 22, 2021 at 7:40 PM Namhyung Kim <namhyung@kernel.org> wrote: > > Add an option to control synthesize behavior. > > --synth <no|all|task|mmap|cgroup> > Fine-tune event synthesis: default=all > > This can be useful when we know it doesn't need some synthesis like > in a specific usecase and/or when using pipe: > > $ perf record -a --all-cgroups --synth cgroup -o- sleep 1 | \ > > perf report -i- -s cgroup > > Signed-off-by: Namhyung Kim <namhyung@kernel.org> > --- > tools/perf/Documentation/perf-record.txt | 4 ++ > tools/perf/builtin-record.c | 48 +++++++++++++++++++----- > tools/perf/util/record.h | 1 + > tools/perf/util/synthetic-events.c | 28 ++++++++++++++ > tools/perf/util/synthetic-events.h | 12 ++++++ > 5 files changed, 84 insertions(+), 9 deletions(-) > > diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt > index d71bac847936..421a7b93c4b5 100644 > --- a/tools/perf/Documentation/perf-record.txt > +++ b/tools/perf/Documentation/perf-record.txt > @@ -596,6 +596,10 @@ options. > 'perf record --dry-run -e' can act as a BPF script compiler if llvm.dump-obj > in config file is set to true. > > +--synth=TYPE:: > +Collect and synthesize given type of events. Available types are: > +task, mmap, cgroup, all, no > +
I would explain what each option disables in the synthesis. It is not clear in your description or your explain in the commit msg.
> > --tail-synthesize:: > Instead of collecting non-sample events (for example, fork, comm, mmap) at > the beginning of record, collect them during finalizing an output file. > diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c > index 535da4dfd8d3..caaada3594ce 100644 > --- a/tools/perf/builtin-record.c > +++ b/tools/perf/builtin-record.c > @@ -1254,6 +1254,7 @@ static int record__synthesize_workload(struct record *rec, bool tail) > { > int err; > struct perf_thread_map *thread_map; > + bool needs_mmap = rec->opts.synth & PERF_SYNTH_MMAP; > > if (rec->opts.tail_synthesize != tail) > return 0; > @@ -1265,7 +1266,7 @@ static int record__synthesize_workload(struct record *rec, bool tail) > err = perf_event__synthesize_thread_map(&rec->tool, thread_map, > process_synthesized_event, > &rec->session->machines.host, > - true, > + needs_mmap, > rec->opts.sample_address); > perf_thread_map__put(thread_map); > return err; > @@ -1500,20 +1501,26 @@ static int record__synthesize(struct record *rec, bool tail) > if (err < 0) > pr_warning("Couldn't synthesize bpf events.\n"); > > - err = perf_event__synthesize_cgroups(tool, process_synthesized_event, > - machine); > - if (err < 0) > - pr_warning("Couldn't synthesize cgroup events.\n"); > + if (rec->opts.synth & PERF_SYNTH_CGROUP) { > + err = perf_event__synthesize_cgroups(tool, process_synthesized_event, > + machine); > + if (err < 0) > + pr_warning("Couldn't synthesize cgroup events.\n"); > + } > > if (rec->opts.nr_threads_synthesize > 1) { > perf_set_multithreaded(); > f = process_locked_synthesized_event; > } > > - err = __machine__synthesize_threads(machine, tool, &opts->target, > - rec->evlist->core.threads, > - f, true, opts->sample_address, > - rec->opts.nr_threads_synthesize); > + if (rec->opts.synth & PERF_SYNTH_TASK) { > + bool needs_mmap = rec->opts.synth & PERF_SYNTH_MMAP; > + > + err = __machine__synthesize_threads(machine, tool, &opts->target, > + rec->evlist->core.threads, > + f, needs_mmap, opts->sample_address, > + rec->opts.nr_threads_synthesize); > + } > > if (rec->opts.nr_threads_synthesize > 1) > perf_set_singlethreaded(); > @@ -2422,6 +2429,26 @@ static int process_timestamp_boundary(struct perf_tool *tool, > return 0; > } > > +static int parse_record_synth_option(const struct option *opt, > + const char *str, > + int unset __maybe_unused) > +{ > + struct record_opts *opts = opt->value; > + char *p = strdup(str); > + > + if (p == NULL) > + return -1; > + > + opts->synth = parse_synth_opt(p); > + free(p); > + > + if (opts->synth < 0) { > + pr_err("Invalid synth option: %s\n", str); > + return -1; > + } > + return 0; > +} > + > /* > * XXX Ideally would be local to cmd_record() and passed to a record__new > * because we need to have access to it in record__exit, that is called > @@ -2447,6 +2474,7 @@ static struct record record = { > .nr_threads_synthesize = 1, > .ctl_fd = -1, > .ctl_fd_ack = -1, > + .synth = PERF_SYNTH_ALL, > }, > .tool = { > .sample = process_sample_event, > @@ -2662,6 +2690,8 @@ static struct option __record_options[] = { > "\t\t\t Optionally send control command completion ('ack\\n') to ack-fd descriptor.\n" > "\t\t\t Alternatively, ctl-fifo / ack-fifo will be opened and used as ctl-fd / ack-fd.", > parse_control_option), > + OPT_CALLBACK(0, "synth", &record.opts, "no|all|task|mmap|cgroup", > + "Fine-tune event synthesis: default=all", parse_record_synth_option), > OPT_END() > }; > > diff --git a/tools/perf/util/record.h b/tools/perf/util/record.h > index 68f471d9a88b..ef6c2715fdd9 100644 > --- a/tools/perf/util/record.h > +++ b/tools/perf/util/record.h > @@ -77,6 +77,7 @@ struct record_opts { > int ctl_fd; > int ctl_fd_ack; > bool ctl_fd_close; > + int synth; > }; > > extern const char * const *record_usage; > diff --git a/tools/perf/util/synthetic-events.c b/tools/perf/util/synthetic-events.c > index 566e0859fcfb..9485d0532b9c 100644 > --- a/tools/perf/util/synthetic-events.c > +++ b/tools/perf/util/synthetic-events.c > @@ -2186,3 +2186,31 @@ int perf_event__synthesize_features(struct perf_tool *tool, struct perf_session > free(ff.buf); > return ret; > } > + > +int parse_synth_opt(char *synth) > +{ > + char *p, *q; > + int ret = 0; > + > + if (synth == NULL) > + return -1; > + > + for (q = synth; (p = strsep(&q, ",")); p = q) { > + if (!strcasecmp(p, "no") || !strcasecmp(p, "none")) > + return 0; > + > + if (!strcasecmp(p, "all")) > + return PERF_SYNTH_ALL; > + > + if (!strcasecmp(p, "task")) > + ret |= PERF_SYNTH_TASK; > + else if (!strcasecmp(p, "mmap")) > + ret |= PERF_SYNTH_TASK | PERF_SYNTH_MMAP; > + else if (!strcasecmp(p, "cgroup")) > + ret |= PERF_SYNTH_CGROUP; > + else > + return -1; > + } > + > + return ret; > +} > diff --git a/tools/perf/util/synthetic-events.h b/tools/perf/util/synthetic-events.h > index 61bbdb3b64df..913803506345 100644 > --- a/tools/perf/util/synthetic-events.h > +++ b/tools/perf/util/synthetic-events.h > @@ -26,6 +26,18 @@ struct target; > > union perf_event; > > +enum perf_record_synth { > + PERF_SYNTH_TASK = 1 << 0, > + PERF_SYNTH_MMAP = 1 << 1, > + PERF_SYNTH_CGROUP = 1 << 2, > + > + /* last element */ > + PERF_SYNTH_MAX = 1 << 3, > +}; > +#define PERF_SYNTH_ALL (PERF_SYNTH_MAX - 1) > + > +int parse_synth_opt(char *str); > + > typedef int (*perf_event__handler_t)(struct perf_tool *tool, union perf_event *event, > struct perf_sample *sample, struct machine *machine); > > -- > 2.32.0.432.gabb21c7263-goog >
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