Re: [PATCH v1 2/3] perf parse-events: Make common term list to strbuf helper

[Ian Rogers]

On Wed, Aug 30, 2023 at 7:15 AM Liang, Kan <kan.liang@xxxxxxxxxxxxxxx> wrote:
>
>
>
> On 2023-08-30 3:07 a.m., Ian Rogers wrote:
> > A term list is turned into a string for debug output and for the str
> > value in the alias. Add a helper to do this based on existing code,
> > but then fix for situations like events being identified. Use strbuf
> > to manage the dynamic memory allocation and remove the 256 byte
> > limit. Use in various places the string of the term list is required.
> >
> > Before:
> > ```
> > $ sudo perf stat -vv -e inst_retired.any true
> > Using CPUID GenuineIntel-6-8D-1
> > intel_pt default config: tsc,mtc,mtc_period=3,psb_period=3,pt,branch
> > Attempting to add event pmu 'cpu' with 'inst_retired.any,' that may result in non-fatal errors
> > After aliases, add event pmu 'cpu' with 'event,period,' that may result in non-fatal errors
> > inst_retired.any -> cpu/inst_retired.any/
> > ...
> > ```
> >
> > After:
> > ```
> > $ sudo perf stat -vv -e inst_retired.any true
> > Using CPUID GenuineIntel-6-8D-1
> > intel_pt default config: tsc,mtc,mtc_period=3,psb_period=3,pt,branch
> > Attempt to add: cpu/inst_retired.any/
> > ..after resolving event: cpu/event=0xc0,period=0x1e8483/
> > inst_retired.any -> cpu/event=0xc0,period=0x1e8483/
> > ...
> > ```
> >
> > Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
> > ---
> >  tools/perf/util/parse-events.c | 101 ++++++++++++++++++++++++---------
> >  tools/perf/util/parse-events.h |   2 +
> >  tools/perf/util/pmu.c          |  19 ++-----
> >  3 files changed, 81 insertions(+), 41 deletions(-)
>
> Which branch should I use to apply the patch?
> I tried the perf-tools-next branch, but there is some conflict.
> I'd like to do some tests on a hybrid machine.

I was working on tmp.perf-tools-next but it is the same as
perf-tools-next currently [1]. I had this 2 line patch in place:
https://lore.kernel.org/lkml/20230830000545.1638964-1-irogers@xxxxxxxxxx/
so that may be the conflict.

Thanks,
Ian

[1] https://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools-next.git/log/?h=tmp.perf-tools-next

> Thanks,
> Kan
> >
> > diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
> > index 4c812fbe0cf9..0b941b58bdc0 100644
> > --- a/tools/perf/util/parse-events.c
> > +++ b/tools/perf/util/parse-events.c
> > @@ -13,7 +13,7 @@
> >  #include <subcmd/parse-options.h>
> >  #include "parse-events.h"
> >  #include "string2.h"
> > -#include "strlist.h"
> > +#include "strbuf.h"
> >  #include "debug.h"
> >  #include <api/fs/tracing_path.h>
> >  #include <perf/cpumap.h>
> > @@ -1303,19 +1303,6 @@ int parse_events_add_pmu(struct parse_events_state *parse_state,
> >
> >       pmu = parse_state->fake_pmu ?: perf_pmus__find(name);
> >
> > -     if (verbose > 1 && !(pmu && pmu->selectable)) {
> > -             fprintf(stderr, "Attempting to add event pmu '%s' with '",
> > -                     name);
> > -             if (head_config) {
> > -                     struct parse_events_term *term;
> > -
> > -                     list_for_each_entry(term, head_config, list) {
> > -                             fprintf(stderr, "%s,", term->config);
> > -                     }
> > -             }
> > -             fprintf(stderr, "' that may result in non-fatal errors\n");
> > -     }
> > -
> >       if (!pmu) {
> >               char *err_str;
> >
> > @@ -1325,6 +1312,21 @@ int parse_events_add_pmu(struct parse_events_state *parse_state,
> >                       parse_events_error__handle(err, loc->first_column, err_str, NULL);
> >               return -EINVAL;
> >       }
> > +
> > +     if (verbose > 1) {
> > +             struct strbuf sb;
> > +
> > +             strbuf_init(&sb, /*hint=*/ 0);
> > +             if (pmu->selectable && !head_config) {
> > +                     strbuf_addf(&sb, "%s//", name);
> > +             } else {
> > +                     strbuf_addf(&sb, "%s/", name);
> > +                     parse_events_term__to_strbuf(head_config, &sb);
> > +                     strbuf_addch(&sb, '/');
> > +             }
> > +             fprintf(stderr, "Attempt to add: %s\n", sb.buf);
> > +             strbuf_release(&sb);
> > +     }
> >       if (head_config)
> >               fix_raw(head_config, pmu);
> >
> > @@ -1349,16 +1351,12 @@ int parse_events_add_pmu(struct parse_events_state *parse_state,
> >               return -EINVAL;
> >
> >       if (verbose > 1) {
> > -             fprintf(stderr, "After aliases, add event pmu '%s' with '",
> > -                     name);
> > -             if (head_config) {
> > -                     struct parse_events_term *term;
> > +             struct strbuf sb;
> >
> > -                     list_for_each_entry(term, head_config, list) {
> > -                             fprintf(stderr, "%s,", term->config);
> > -                     }
> > -             }
> > -             fprintf(stderr, "' that may result in non-fatal errors\n");
> > +             strbuf_init(&sb, /*hint=*/ 0);
> > +             parse_events_term__to_strbuf(head_config, &sb);
> > +             fprintf(stderr, "..after resolving event: %s/%s/\n", name, sb.buf);
> > +             strbuf_release(&sb);
> >       }
> >
> >       /*
> > @@ -1460,7 +1458,12 @@ int parse_events_multi_pmu_add(struct parse_events_state *parse_state,
> >               parse_events_copy_term_list(head, &orig_head);
> >               if (!parse_events_add_pmu(parse_state, list, pmu->name,
> >                                         orig_head, auto_merge_stats, loc)) {
> > -                     pr_debug("%s -> %s/%s/\n", str, pmu->name, str);
> > +                     struct strbuf sb;
> > +
> > +                     strbuf_init(&sb, /*hint=*/ 0);
> > +                     parse_events_term__to_strbuf(orig_head, &sb);
> > +                     pr_debug("%s -> %s/%s/\n", str, pmu->name, sb.buf);
> > +                     strbuf_release(&sb);
> >                       ok++;
> >               }
> >               parse_events_terms__delete(orig_head);
> > @@ -1469,7 +1472,12 @@ int parse_events_multi_pmu_add(struct parse_events_state *parse_state,
> >       if (parse_state->fake_pmu) {
> >               if (!parse_events_add_pmu(parse_state, list, str, head,
> >                                         /*auto_merge_stats=*/true, loc)) {
> > -                     pr_debug("%s -> %s/%s/\n", str, "fake_pmu", str);
> > +                     struct strbuf sb;
> > +
> > +                     strbuf_init(&sb, /*hint=*/ 0);
> > +                     parse_events_term__to_strbuf(head, &sb);
> > +                     pr_debug("%s -> %s/%s/\n", str, "fake_pmu", sb.buf);
> > +                     strbuf_release(&sb);
> >                       ok++;
> >               }
> >       }
> > @@ -2085,7 +2093,7 @@ void parse_events_error__handle(struct parse_events_error *err, int idx,
> >               break;
> >       default:
> >               pr_debug("Multiple errors dropping message: %s (%s)\n",
> > -                     err->str, err->help);
> > +                     err->str, err->help ?: "<no help>");
> >               free(err->str);
> >               err->str = str;
> >               free(err->help);
> > @@ -2502,6 +2510,47 @@ void parse_events_terms__delete(struct list_head *terms)
> >       free(terms);
> >  }
> >
> > +int parse_events_term__to_strbuf(struct list_head *term_list, struct strbuf *sb)
> > +{
> > +     struct parse_events_term *term;
> > +     bool first = true;
> > +
> > +     if (!term_list)
> > +             return 0;
> > +
> > +     list_for_each_entry(term, term_list, list) {
> > +             int ret;
> > +
> > +             if (!first) {
> > +                     ret = strbuf_addch(sb, ',');
> > +                     if (ret < 0)
> > +                             return ret;
> > +             }
> > +             first = false;
> > +
> > +             if (term->type_val == PARSE_EVENTS__TERM_TYPE_NUM)
> > +                     if (term->type_term == PARSE_EVENTS__TERM_TYPE_USER && term->val.num == 1)
> > +                             ret = strbuf_addf(sb, "%s", term->config);
> > +                     else
> > +                             ret = strbuf_addf(sb, "%s=%#"PRIx64, term->config, term->val.num);
> > +             else if (term->type_val == PARSE_EVENTS__TERM_TYPE_STR) {
> > +                     if (term->config) {
> > +                             ret = strbuf_addf(sb, "%s=", term->config);
> > +                             if (ret < 0)
> > +                                     return ret;
> > +                     } else if (term->type_term < __PARSE_EVENTS__TERM_TYPE_NR) {
> > +                             ret = strbuf_addf(sb, "%s=", config_term_names[term->type_term]);
> > +                             if (ret < 0)
> > +                                     return ret;
> > +                     }
> > +                     ret = strbuf_addf(sb, "%s", term->val.str);
> > +             }
> > +             if (ret < 0)
> > +                     return ret;
> > +     }
> > +     return 0;
> > +}
> > +
> >  void parse_events_evlist_error(struct parse_events_state *parse_state,
> >                              int idx, const char *str)
> >  {
> > diff --git a/tools/perf/util/parse-events.h b/tools/perf/util/parse-events.h
> > index 6d75d853ce00..20bdc35d6112 100644
> > --- a/tools/perf/util/parse-events.h
> > +++ b/tools/perf/util/parse-events.h
> > @@ -18,6 +18,7 @@ struct parse_events_error;
> >
> >  struct option;
> >  struct perf_pmu;
> > +struct strbuf;
> >
> >  const char *event_type(int type);
> >
> > @@ -152,6 +153,7 @@ int parse_events_term__clone(struct parse_events_term **new,
> >  void parse_events_term__delete(struct parse_events_term *term);
> >  void parse_events_terms__delete(struct list_head *terms);
> >  void parse_events_terms__purge(struct list_head *terms);
> > +int parse_events_term__to_strbuf(struct list_head *term_list, struct strbuf *sb);
> >  int parse_events__modifier_event(struct list_head *list, char *str, bool add);
> >  int parse_events__modifier_group(struct list_head *list, char *event_mod);
> >  int parse_events_name(struct list_head *list, const char *name);
> > diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
> > index b3f8f3f1e900..8dbb7008877e 100644
> > --- a/tools/perf/util/pmu.c
> > +++ b/tools/perf/util/pmu.c
> > @@ -507,12 +507,11 @@ static int perf_pmu__new_alias(struct perf_pmu *pmu, const char *name,
> >                               const char *desc, const char *val, FILE *val_fd,
> >                               const struct pmu_event *pe)
> >  {
> > -     struct parse_events_term *term;
> >       struct perf_pmu_alias *alias;
> >       int ret;
> > -     char newval[256];
> >       const char *long_desc = NULL, *topic = NULL, *unit = NULL, *pmu_name = NULL;
> >       bool deprecated = false, perpkg = false;
> > +     struct strbuf sb;
> >
> >       if (perf_pmu__find_alias(pmu, name, /*load=*/ false)) {
> >               /* Alias was already created/loaded. */
> > @@ -582,20 +581,10 @@ static int perf_pmu__new_alias(struct perf_pmu *pmu, const char *name,
> >        *
> >        * Rebuild string to make alias->str member comparable.
> >        */
> > -     ret = 0;
> > -     list_for_each_entry(term, &alias->terms, list) {
> > -             if (ret)
> > -                     ret += scnprintf(newval + ret, sizeof(newval) - ret,
> > -                                      ",");
> > -             if (term->type_val == PARSE_EVENTS__TERM_TYPE_NUM)
> > -                     ret += scnprintf(newval + ret, sizeof(newval) - ret,
> > -                                      "%s=%#x", term->config, term->val.num);
> > -             else if (term->type_val == PARSE_EVENTS__TERM_TYPE_STR)
> > -                     ret += scnprintf(newval + ret, sizeof(newval) - ret,
> > -                                      "%s=%s", term->config, term->val.str);
> > -     }
> >       zfree(&alias->str);
> > -     alias->str = strdup(newval);
> > +     strbuf_init(&sb, /*hint=*/ 0);
> > +     parse_events_term__to_strbuf(&alias->terms, &sb);
> > +     alias->str = strbuf_detach(&sb, /*sz=*/ NULL);
> >       if (!pe)
> >               pmu->sysfs_aliases++;
> >       else