Messages in this thread | | | From | "Wang, Weilin" <> | Subject | RE: [RFC PATCH v5 2/6] perf stat: Fork and launch perf record when perf stat needs to get retire latency value for a metric. | Date | Fri, 29 Mar 2024 17:25:15 +0000 |
| |
> -----Original Message----- > From: Namhyung Kim <namhyung@kernel.org> > Sent: Thursday, March 28, 2024 11:43 PM > To: Wang, Weilin <weilin.wang@intel.com> > Cc: Ian Rogers <irogers@google.com>; Arnaldo Carvalho de Melo > <acme@kernel.org>; Peter Zijlstra <peterz@infradead.org>; Ingo Molnar > <mingo@redhat.com>; Alexander Shishkin > <alexander.shishkin@linux.intel.com>; Jiri Olsa <jolsa@kernel.org>; Hunter, > Adrian <adrian.hunter@intel.com>; Kan Liang <kan.liang@linux.intel.com>; > linux-perf-users@vger.kernel.org; linux-kernel@vger.kernel.org; Taylor, Perry > <perry.taylor@intel.com>; Alt, Samantha <samantha.alt@intel.com>; Biggers, > Caleb <caleb.biggers@intel.com> > Subject: Re: [RFC PATCH v5 2/6] perf stat: Fork and launch perf record when > perf stat needs to get retire latency value for a metric. > > On Tue, Mar 26, 2024 at 1:29 PM <weilin.wang@intel.com> wrote: > > > > From: Weilin Wang <weilin.wang@intel.com> > > > > When retire_latency value is used in a metric formula, perf stat would fork a > > perf record process with "-e" and "-W" options. Perf record will collect > > required retire_latency values in parallel while perf stat is collecting > > counting values. > > > > At the point of time that perf stat stops counting, it would send sigterm > signal > > to perf record process and receiving sampling data back from perf record > from a > > pipe. Perf stat will then process the received data to get retire latency data > > and calculate metric result. > > I'm afraid this requirement is too Intel specific. Maybe we need to move > the code to somewhere under the arch directory. > > > > > Signed-off-by: Weilin Wang <weilin.wang@intel.com> > > Reviewed-by: Ian Rogers <irogers@google.com> > > --- > > tools/perf/builtin-stat.c | 165 > +++++++++++++++++++++++++++++++++- > > tools/perf/util/data.c | 3 + > > tools/perf/util/data.h | 5 ++ > > tools/perf/util/metricgroup.h | 8 ++ > > tools/perf/util/stat.h | 2 + > > 5 files changed, 181 insertions(+), 2 deletions(-) > > > > diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c > > index 6291e1e24535..fb08cef42d95 100644 > > --- a/tools/perf/builtin-stat.c > > +++ b/tools/perf/builtin-stat.c > > @@ -94,8 +94,13 @@ > > #include <perf/evlist.h> > > #include <internal/threadmap.h> > > > > +#include "util/sample.h" > > +#include <sys/param.h> > > +#include <subcmd/run-command.h> > > + > > #define DEFAULT_SEPARATOR " " > > #define FREEZE_ON_SMI_PATH "devices/cpu/freeze_on_smi" > > +#define PERF_DATA "-" > > > > static void print_counters(struct timespec *ts, int argc, const char **argv); > > > > @@ -163,6 +168,8 @@ static struct perf_stat_config stat_config = { > > .ctl_fd_ack = -1, > > .iostat_run = false, > > .tpebs_events = LIST_HEAD_INIT(stat_config.tpebs_events), > > + .tpebs_results = LIST_HEAD_INIT(stat_config.tpebs_results), > > + .tpebs_pid = -1, > > }; > > > > static bool cpus_map_matched(struct evsel *a, struct evsel *b) > > @@ -687,12 +694,155 @@ static enum counter_recovery > stat_handle_error(struct evsel *counter) > > return COUNTER_FATAL; > > } > > > > -static int __run_perf_record(void) > > +static int __run_perf_record(const char **record_argv) > > { > > + int i = 0; > > + struct tpebs_event *e; > > + > > pr_debug("Prepare perf record for retire_latency\n"); > > + > > + record_argv[i++] = "perf"; > > + record_argv[i++] = "record"; > > + record_argv[i++] = "-W"; > > + record_argv[i++] = "--synth=no"; > > + > > + if (stat_config.user_requested_cpu_list) { > > + record_argv[i++] = "-C"; > > + record_argv[i++] = stat_config.user_requested_cpu_list; > > + } > > + > > + if (stat_config.system_wide) > > + record_argv[i++] = "-a"; > > What do you want to do if neither of -a nor -C is used? > Maybe you can disable perf record in background. > > > + > > + list_for_each_entry(e, &stat_config.tpebs_events, nd) { > > + record_argv[i++] = "-e"; > > + record_argv[i++] = e->name; > > + } > > + > > + record_argv[i++] = "-o"; > > + record_argv[i++] = PERF_DATA; > > + > > return 0; > > } > > > > +static void prepare_run_command(struct child_process *cmd, > > + const char **argv) > > +{ > > + memset(cmd, 0, sizeof(*cmd)); > > + cmd->argv = argv; > > + cmd->out = -1; > > +} > > + > > +static int prepare_perf_record(struct child_process *cmd) > > +{ > > + const char **record_argv; > > + > > + record_argv = calloc(10 + 2 * stat_config.tpebs_event_size, sizeof(char > *)); > > + if (!record_argv) > > + return -1; > > + __run_perf_record(record_argv); > > + > > + prepare_run_command(cmd, record_argv); > > + return start_command(cmd); > > +} > > + > > +struct perf_script { > > + struct perf_tool tool; > > + struct perf_session *session; > > +}; > > + > > +static void tpebs_data__delete(void) > > +{ > > + struct tpebs_retire_lat *r, *rtmp; > > + struct tpebs_event *e, *etmp; > > A blank line please. > > > + list_for_each_entry_safe(r, rtmp, &stat_config.tpebs_results, event.nd) > { > > + list_del_init(&r->event.nd); > > + free(r); > > + } > > + list_for_each_entry_safe(e, etmp, &stat_config.tpebs_events, nd) { > > + list_del_init(&e->nd); > > + free(e); > > + } > > +} > > + > > +static int process_sample_event(struct perf_tool *tool __maybe_unused, > > + union perf_event *event __maybe_unused, > > + struct perf_sample *sample, > > + struct evsel *evsel, > > + struct machine *machine __maybe_unused) > > +{ > > + int ret = 0; > > + const char *evname; > > + struct tpebs_retire_lat *t; > > + > > + evname = evsel__name(evsel); > > + > > + /* > > + * Need to handle per core results? We are assuming average retire > > + * latency value will be used. Save the number of samples and the sum > of > > + * retire latency value for each event. > > + */ > > + list_for_each_entry(t, &stat_config.tpebs_results, event.nd) { > > + if (!strcmp(evname, t->event.name)) { > > + t->count += 1; > > + t->sum += sample->retire_lat; > > + break; > > + } > > + } > > + > > + return ret; > > +} > > + > > +static int process_feature_event(struct perf_session *session, > > + union perf_event *event) > > +{ > > + if (event->feat.feat_id < HEADER_LAST_FEATURE) > > + return perf_event__process_feature(session, event); > > + return 0; > > +} > > + > > +static int __cmd_script(struct child_process *cmd __maybe_unused) > > +{ > > + int err = 0; > > + struct perf_session *session; > > + struct perf_data data = { > > + .mode = PERF_DATA_MODE_READ, > > + .path = PERF_DATA, > > + .fd = cmd->out, > > I don't like this part as it added the fd field unnecessarily. > I think we need a new session API that can pass a fd directly. > > > > + }; > > + struct perf_script script = { > > + .tool = { > > + .sample = process_sample_event, > > + .ordering_requires_timestamps = true, > > Is this really needed? I don't think it needs ordering. > > > > + .feature = process_feature_event, > > + .attr = perf_event__process_attr, > > + }, > > + }; > > + struct tpebs_event *e; > > + > > + list_for_each_entry(e, &stat_config.tpebs_events, nd) { > > + struct tpebs_retire_lat *new = malloc(sizeof(struct > tpebs_retire_lat)); > > + > > + if (!new) > > + return -1; > > + new->event.name = strdup(e->name); > > + new->event.tpebs_name = strdup(e->tpebs_name); > > + new->count = 0; > > + new->sum = 0; > > + list_add_tail(&new->event.nd, &stat_config.tpebs_results); > > + } > > + > > + kill(cmd->pid, SIGTERM); > > Is this the only place to stop the perf record? > What if perf stat exits before calling this function? > > > > + session = perf_session__new(&data, &script.tool); > > + if (IS_ERR(session)) > > + return PTR_ERR(session); > > + script.session = session; > > + err = perf_session__process_events(session); > > + perf_session__delete(session); > > + > > + return err; > > +} > > + > > static int __run_perf_stat(int argc, const char **argv, int run_idx) > > { > > int interval = stat_config.interval; > > @@ -709,13 +859,15 @@ static int __run_perf_stat(int argc, const char > **argv, int run_idx) > > struct affinity saved_affinity, *affinity = NULL; > > int err; > > bool second_pass = false; > > + struct child_process cmd; > > > > /* Prepare perf record for sampling event retire_latency before fork and > > * prepare workload */ > > if (stat_config.tpebs_event_size > 0) { > > int ret; > > > > - ret = __run_perf_record(); > > + pr_debug("perf stat pid = %d\n", getpid()); > > + ret = prepare_perf_record(&cmd); > > if (ret) > > return ret; > > } > > @@ -925,6 +1077,13 @@ static int __run_perf_stat(int argc, const char > **argv, int run_idx) > > > > t1 = rdclock(); > > > > + if (stat_config.tpebs_event_size > 0) { > > + int ret; > > + > > + ret = __cmd_script(&cmd); > > + close(cmd.out); > > + } > > + > > if (stat_config.walltime_run_table) > > stat_config.walltime_run[run_idx] = t1 - t0; > > > > @@ -2972,5 +3131,7 @@ int cmd_stat(int argc, const char **argv) > > metricgroup__rblist_exit(&stat_config.metric_events); > > evlist__close_control(stat_config.ctl_fd, stat_config.ctl_fd_ack, > &stat_config.ctl_fd_close); > > > > + tpebs_data__delete(); > > + > > return status; > > } > > diff --git a/tools/perf/util/data.c b/tools/perf/util/data.c > > index 08c4bfbd817f..f6cc0ccdec5e 100644 > > --- a/tools/perf/util/data.c > > +++ b/tools/perf/util/data.c > > @@ -185,6 +185,9 @@ static bool check_pipe(struct perf_data *data) > > int fd = perf_data__is_read(data) ? > > STDIN_FILENO : STDOUT_FILENO; > > > > + if (data->fd > 0) > > + fd = data->fd; > > + > > if (!data->path) { > > if (!fstat(fd, &st) && S_ISFIFO(st.st_mode)) > > is_pipe = true; > > diff --git a/tools/perf/util/data.h b/tools/perf/util/data.h > > index 110f3ebde30f..f5e7479f1892 100644 > > --- a/tools/perf/util/data.h > > +++ b/tools/perf/util/data.h > > @@ -28,6 +28,11 @@ struct perf_data_file { > > > > struct perf_data { > > const char *path; > > + /* > > + * When fd is given, use PIPE instead of file, use given fd instead of > > + * STDIN_FILENO or STDOUT_FILENO > > + */ > > + int fd; > > Maybe users can set data.file.fd directly instead of this.
This will require a little code change in function check_pipe() in data.c. Do you want me to update that?
Thanks, Weilin
> > > > struct perf_data_file file; > > bool is_pipe; > > bool is_dir; > > diff --git a/tools/perf/util/metricgroup.h b/tools/perf/util/metricgroup.h > > index 7c24ed768ff3..e5bafb45d4d9 100644 > > --- a/tools/perf/util/metricgroup.h > > +++ b/tools/perf/util/metricgroup.h > > @@ -68,10 +68,18 @@ struct metric_expr { > > > > struct tpebs_event { > > struct list_head nd; > > + /* Event name */ > > const char *name; > > + /* Event name with TPEBS modifier */ > > What is the TPEBS modifier? > > Thanks, > Namhyung > > > > const char *tpebs_name; > > }; > > > > +struct tpebs_retire_lat { > > + struct tpebs_event event; > > + size_t count; > > + int sum; > > +}; > > + > > struct metric_event *metricgroup__lookup(struct rblist *metric_events, > > struct evsel *evsel, > > bool create); > > diff --git a/tools/perf/util/stat.h b/tools/perf/util/stat.h > > index b987960df3c5..0726bdc06681 100644 > > --- a/tools/perf/util/stat.h > > +++ b/tools/perf/util/stat.h > > @@ -111,6 +111,8 @@ struct perf_stat_config { > > struct rblist metric_events; > > struct list_head tpebs_events; > > size_t tpebs_event_size; > > + struct list_head tpebs_results; > > + pid_t tpebs_pid; > > int ctl_fd; > > int ctl_fd_ack; > > bool ctl_fd_close; > > -- > > 2.43.0 > >
| |