perf list: Add output file option

Add an option to write the 'perf list' output to a specific file. This
can avoid issues with debug output being written into the output stream.

Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Ross Zwisler <zwisler@chromium.org>
Cc: Shirisha G <shirisha@linux.ibm.com>
Link: https://lore.kernel.org/r/20240124043015.1388867-3-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/Documentation/perf-list.txt b/tools/perf/Documentation/perf-list.txt
index 1b90575ee3c84eb206f9291e8fd05d43c70b2f9c..3b12595193c9f49a78a490b888f22d615b92dc43 100644 (file)
--- a/tools/perf/Documentation/perf-list.txt
+++ b/tools/perf/Documentation/perf-list.txt
@@ -47,6 +47,10 @@ Print PMU events and metrics limited to the specific PMU name.
 --json::
 Output in JSON format.
 
+-o::
+--output=::
+       Output file name. By default output is written to stdout.
+
 [[EVENT_MODIFIERS]]
 EVENT MODIFIERS
 ---------------

diff --git a/tools/perf/builtin-list.c b/tools/perf/builtin-list.c
index 61c2c96cc0701b886d7c1daecd92cfa25581d1f7..e27a1b1288c29ffe96ce871bc5bab76c8a67c8b7 100644 (file)
--- a/tools/perf/builtin-list.c
+++ b/tools/perf/builtin-list.c
@@ -30,6 +30,8 @@
  * functions.
  */
 struct print_state {
+       /** @fp: File to write output to. */
+       FILE *fp;
        /**
         * @pmu_glob: Optionally restrict PMU and metric matching to PMU or
         * debugfs subsystem name.
@@ -66,13 +68,15 @@ static void default_print_start(void *ps)
 {
        struct print_state *print_state = ps;
 
-       if (!print_state->name_only && pager_in_use())
-               printf("\nList of pre-defined events (to be used in -e or -M):\n\n");
+       if (!print_state->name_only && pager_in_use()) {
+               fprintf(print_state->fp,
+                       "\nList of pre-defined events (to be used in -e or -M):\n\n");
+       }
 }
 
 static void default_print_end(void *print_state __maybe_unused) {}
 
-static void wordwrap(const char *s, int start, int max, int corr)
+static void wordwrap(FILE *fp, const char *s, int start, int max, int corr)
 {
        int column = start;
        int n;
@@ -82,10 +86,10 @@ static void wordwrap(const char *s, int start, int max, int corr)
                int wlen = strcspn(s, " \t\n");
 
                if ((column + wlen >= max && column > start) || saw_newline) {
-                       printf("\n%*s", start, "");
+                       fprintf(fp, "\n%*s", start, "");
                        column = start + corr;
                }
-               n = printf("%s%.*s", column > start ? " " : "", wlen, s);
+               n = fprintf(fp, "%s%.*s", column > start ? " " : "", wlen, s);
                if (n <= 0)
                        break;
                saw_newline = s[wlen] == '\n';
@@ -104,6 +108,7 @@ static void default_print_event(void *ps, const char *pmu_name, const char *topi
 {
        struct print_state *print_state = ps;
        int pos;
+       FILE *fp = print_state->fp;
 
        if (deprecated && !print_state->deprecated)
                return;
@@ -119,30 +124,30 @@ static void default_print_event(void *ps, const char *pmu_name, const char *topi
 
        if (print_state->name_only) {
                if (event_alias && strlen(event_alias))
-                       printf("%s ", event_alias);
+                       fprintf(fp, "%s ", event_alias);
                else
-                       printf("%s ", event_name);
+                       fprintf(fp, "%s ", event_name);
                return;
        }
 
        if (strcmp(print_state->last_topic, topic ?: "")) {
                if (topic)
-                       printf("\n%s:\n", topic);
+                       fprintf(fp, "\n%s:\n", topic);
                zfree(&print_state->last_topic);
                print_state->last_topic = strdup(topic ?: "");
        }
 
        if (event_alias && strlen(event_alias))
-               pos = printf("  %s OR %s", event_name, event_alias);
+               pos = fprintf(fp, "  %s OR %s", event_name, event_alias);
        else
-               pos = printf("  %s", event_name);
+               pos = fprintf(fp, "  %s", event_name);
 
        if (!topic && event_type_desc) {
                for (; pos < 53; pos++)
-                       putchar(' ');
-               printf("[%s]\n", event_type_desc);
+                       fputc(' ', fp);
+               fprintf(fp, "[%s]\n", event_type_desc);
        } else
-               putchar('\n');
+               fputc('\n', fp);
 
        if (desc && print_state->desc) {
                char *desc_with_unit = NULL;
@@ -155,22 +160,22 @@ static void default_print_event(void *ps, const char *pmu_name, const char *topi
                                              ? "%s. Unit: %s" : "%s Unit: %s",
                                            desc, pmu_name);
                }
-               printf("%*s", 8, "[");
-               wordwrap(desc_len > 0 ? desc_with_unit : desc, 8, pager_get_columns(), 0);
-               printf("]\n");
+               fprintf(fp, "%*s", 8, "[");
+               wordwrap(fp, desc_len > 0 ? desc_with_unit : desc, 8, pager_get_columns(), 0);
+               fprintf(fp, "]\n");
                free(desc_with_unit);
        }
        long_desc = long_desc ?: desc;
        if (long_desc && print_state->long_desc) {
-               printf("%*s", 8, "[");
-               wordwrap(long_desc, 8, pager_get_columns(), 0);
-               printf("]\n");
+               fprintf(fp, "%*s", 8, "[");
+               wordwrap(fp, long_desc, 8, pager_get_columns(), 0);
+               fprintf(fp, "]\n");
        }
 
        if (print_state->detailed && encoding_desc) {
-               printf("%*s", 8, "");
-               wordwrap(encoding_desc, 8, pager_get_columns(), 0);
-               putchar('\n');
+               fprintf(fp, "%*s", 8, "");
+               wordwrap(fp, encoding_desc, 8, pager_get_columns(), 0);
+               fputc('\n', fp);
        }
 }
 
@@ -184,6 +189,7 @@ static void default_print_metric(void *ps,
                                const char *unit __maybe_unused)
 {
        struct print_state *print_state = ps;
+       FILE *fp = print_state->fp;
 
        if (print_state->event_glob &&
            (!print_state->metrics || !name || !strglobmatch(name, print_state->event_glob)) &&
@@ -192,27 +198,27 @@ static void default_print_metric(void *ps,
 
        if (!print_state->name_only && !print_state->last_metricgroups) {
                if (print_state->metricgroups) {
-                       printf("\nMetric Groups:\n");
+                       fprintf(fp, "\nMetric Groups:\n");
                        if (!print_state->metrics)
-                               putchar('\n');
+                               fputc('\n', fp);
                } else {
-                       printf("\nMetrics:\n\n");
+                       fprintf(fp, "\nMetrics:\n\n");
                }
        }
        if (!print_state->last_metricgroups ||
            strcmp(print_state->last_metricgroups, group ?: "")) {
                if (group && print_state->metricgroups) {
                        if (print_state->name_only)
-                               printf("%s ", group);
+                               fprintf(fp, "%s ", group);
                        else if (print_state->metrics) {
                                const char *gdesc = describe_metricgroup(group);
 
                                if (gdesc)
-                                       printf("\n%s: [%s]\n", group, gdesc);
+                                       fprintf(fp, "\n%s: [%s]\n", group, gdesc);
                                else
-                                       printf("\n%s:\n", group);
+                                       fprintf(fp, "\n%s:\n", group);
                        } else
-                               printf("%s\n", group);
+                               fprintf(fp, "%s\n", group);
                }
                zfree(&print_state->last_metricgroups);
                print_state->last_metricgroups = strdup(group ?: "");
@@ -223,53 +229,59 @@ static void default_print_metric(void *ps,
        if (print_state->name_only) {
                if (print_state->metrics &&
                    !strlist__has_entry(print_state->visited_metrics, name)) {
-                       printf("%s ", name);
+                       fprintf(fp, "%s ", name);
                        strlist__add(print_state->visited_metrics, name);
                }
                return;
        }
-       printf("  %s\n", name);
+       fprintf(fp, "  %s\n", name);
 
        if (desc && print_state->desc) {
-               printf("%*s", 8, "[");
-               wordwrap(desc, 8, pager_get_columns(), 0);
-               printf("]\n");
+               fprintf(fp, "%*s", 8, "[");
+               wordwrap(fp, desc, 8, pager_get_columns(), 0);
+               fprintf(fp, "]\n");
        }
        if (long_desc && print_state->long_desc) {
-               printf("%*s", 8, "[");
-               wordwrap(long_desc, 8, pager_get_columns(), 0);
-               printf("]\n");
+               fprintf(fp, "%*s", 8, "[");
+               wordwrap(fp, long_desc, 8, pager_get_columns(), 0);
+               fprintf(fp, "]\n");
        }
        if (expr && print_state->detailed) {
-               printf("%*s", 8, "[");
-               wordwrap(expr, 8, pager_get_columns(), 0);
-               printf("]\n");
+               fprintf(fp, "%*s", 8, "[");
+               wordwrap(fp, expr, 8, pager_get_columns(), 0);
+               fprintf(fp, "]\n");
        }
        if (threshold && print_state->detailed) {
-               printf("%*s", 8, "[");
-               wordwrap(threshold, 8, pager_get_columns(), 0);
-               printf("]\n");
+               fprintf(fp, "%*s", 8, "[");
+               wordwrap(fp, threshold, 8, pager_get_columns(), 0);
+               fprintf(fp, "]\n");
        }
 }
 
 struct json_print_state {
+       /** @fp: File to write output to. */
+       FILE *fp;
        /** Should a separator be printed prior to the next item? */
        bool need_sep;
 };
 
-static void json_print_start(void *print_state __maybe_unused)
+static void json_print_start(void *ps)
 {
-       printf("[\n");
+       struct json_print_state *print_state = ps;
+       FILE *fp = print_state->fp;
+
+       fprintf(fp, "[\n");
 }
 
 static void json_print_end(void *ps)
 {
        struct json_print_state *print_state = ps;
+       FILE *fp = print_state->fp;
 
-       printf("%s]\n", print_state->need_sep ? "\n" : "");
+       fprintf(fp, "%s]\n", print_state->need_sep ? "\n" : "");
 }
 
-static void fix_escape_printf(struct strbuf *buf, const char *fmt, ...)
+static void fix_escape_fprintf(FILE *fp, struct strbuf *buf, const char *fmt, ...)
 {
        va_list args;
 
@@ -318,7 +330,7 @@ static void fix_escape_printf(struct strbuf *buf, const char *fmt, ...)
                }
        }
        va_end(args);
-       fputs(buf->buf, stdout);
+       fputs(buf->buf, fp);
 }
 
 static void json_print_event(void *ps, const char *pmu_name, const char *topic,
@@ -330,60 +342,71 @@ static void json_print_event(void *ps, const char *pmu_name, const char *topic,
 {
        struct json_print_state *print_state = ps;
        bool need_sep = false;
+       FILE *fp = print_state->fp;
        struct strbuf buf;
 
        strbuf_init(&buf, 0);
-       printf("%s{\n", print_state->need_sep ? ",\n" : "");
+       fprintf(fp, "%s{\n", print_state->need_sep ? ",\n" : "");
        print_state->need_sep = true;
        if (pmu_name) {
-               fix_escape_printf(&buf, "\t\"Unit\": \"%S\"", pmu_name);
+               fix_escape_fprintf(fp, &buf, "\t\"Unit\": \"%S\"", pmu_name);
                need_sep = true;
        }
        if (topic) {
-               fix_escape_printf(&buf, "%s\t\"Topic\": \"%S\"", need_sep ? ",\n" : "", topic);
+               fix_escape_fprintf(fp, &buf, "%s\t\"Topic\": \"%S\"",
+                                  need_sep ? ",\n" : "",
+                                  topic);
                need_sep = true;
        }
        if (event_name) {
-               fix_escape_printf(&buf, "%s\t\"EventName\": \"%S\"", need_sep ? ",\n" : "",
-                                 event_name);
+               fix_escape_fprintf(fp, &buf, "%s\t\"EventName\": \"%S\"",
+                                  need_sep ? ",\n" : "",
+                                  event_name);
                need_sep = true;
        }
        if (event_alias && strlen(event_alias)) {
-               fix_escape_printf(&buf, "%s\t\"EventAlias\": \"%S\"", need_sep ? ",\n" : "",
-                                 event_alias);
+               fix_escape_fprintf(fp, &buf, "%s\t\"EventAlias\": \"%S\"",
+                                  need_sep ? ",\n" : "",
+                                  event_alias);
                need_sep = true;
        }
        if (scale_unit && strlen(scale_unit)) {
-               fix_escape_printf(&buf, "%s\t\"ScaleUnit\": \"%S\"", need_sep ? ",\n" : "",
-                                 scale_unit);
+               fix_escape_fprintf(fp, &buf, "%s\t\"ScaleUnit\": \"%S\"",
+                                  need_sep ? ",\n" : "",
+                                  scale_unit);
                need_sep = true;
        }
        if (event_type_desc) {
-               fix_escape_printf(&buf, "%s\t\"EventType\": \"%S\"", need_sep ? ",\n" : "",
-                                 event_type_desc);
+               fix_escape_fprintf(fp, &buf, "%s\t\"EventType\": \"%S\"",
+                                  need_sep ? ",\n" : "",
+                                  event_type_desc);
                need_sep = true;
        }
        if (deprecated) {
-               fix_escape_printf(&buf, "%s\t\"Deprecated\": \"%S\"", need_sep ? ",\n" : "",
-                                 deprecated ? "1" : "0");
+               fix_escape_fprintf(fp, &buf, "%s\t\"Deprecated\": \"%S\"",
+                                  need_sep ? ",\n" : "",
+                                  deprecated ? "1" : "0");
                need_sep = true;
        }
        if (desc) {
-               fix_escape_printf(&buf, "%s\t\"BriefDescription\": \"%S\"", need_sep ? ",\n" : "",
-                                 desc);
+               fix_escape_fprintf(fp, &buf, "%s\t\"BriefDescription\": \"%S\"",
+                                  need_sep ? ",\n" : "",
+                                  desc);
                need_sep = true;
        }
        if (long_desc) {
-               fix_escape_printf(&buf, "%s\t\"PublicDescription\": \"%S\"", need_sep ? ",\n" : "",
-                                 long_desc);
+               fix_escape_fprintf(fp, &buf, "%s\t\"PublicDescription\": \"%S\"",
+                                  need_sep ? ",\n" : "",
+                                  long_desc);
                need_sep = true;
        }
        if (encoding_desc) {
-               fix_escape_printf(&buf, "%s\t\"Encoding\": \"%S\"", need_sep ? ",\n" : "",
-                                 encoding_desc);
+               fix_escape_fprintf(fp, &buf, "%s\t\"Encoding\": \"%S\"",
+                                  need_sep ? ",\n" : "",
+                                  encoding_desc);
                need_sep = true;
        }
-       printf("%s}", need_sep ? "\n" : "");
+       fprintf(fp, "%s}", need_sep ? "\n" : "");
        strbuf_release(&buf);
 }
 
@@ -394,43 +417,53 @@ static void json_print_metric(void *ps __maybe_unused, const char *group,
 {
        struct json_print_state *print_state = ps;
        bool need_sep = false;
+       FILE *fp = print_state->fp;
        struct strbuf buf;
 
        strbuf_init(&buf, 0);
-       printf("%s{\n", print_state->need_sep ? ",\n" : "");
+       fprintf(fp, "%s{\n", print_state->need_sep ? ",\n" : "");
        print_state->need_sep = true;
        if (group) {
-               fix_escape_printf(&buf, "\t\"MetricGroup\": \"%S\"", group);
+               fix_escape_fprintf(fp, &buf, "\t\"MetricGroup\": \"%S\"", group);
                need_sep = true;
        }
        if (name) {
-               fix_escape_printf(&buf, "%s\t\"MetricName\": \"%S\"", need_sep ? ",\n" : "", name);
+               fix_escape_fprintf(fp, &buf, "%s\t\"MetricName\": \"%S\"",
+                                  need_sep ? ",\n" : "",
+                                  name);
                need_sep = true;
        }
        if (expr) {
-               fix_escape_printf(&buf, "%s\t\"MetricExpr\": \"%S\"", need_sep ? ",\n" : "", expr);
+               fix_escape_fprintf(fp, &buf, "%s\t\"MetricExpr\": \"%S\"",
+                                  need_sep ? ",\n" : "",
+                                  expr);
                need_sep = true;
        }
        if (threshold) {
-               fix_escape_printf(&buf, "%s\t\"MetricThreshold\": \"%S\"", need_sep ? ",\n" : "",
-                                 threshold);
+               fix_escape_fprintf(fp, &buf, "%s\t\"MetricThreshold\": \"%S\"",
+                                  need_sep ? ",\n" : "",
+                                  threshold);
                need_sep = true;
        }
        if (unit) {
-               fix_escape_printf(&buf, "%s\t\"ScaleUnit\": \"%S\"", need_sep ? ",\n" : "", unit);
+               fix_escape_fprintf(fp, &buf, "%s\t\"ScaleUnit\": \"%S\"",
+                                  need_sep ? ",\n" : "",
+                                  unit);
                need_sep = true;
        }
        if (desc) {
-               fix_escape_printf(&buf, "%s\t\"BriefDescription\": \"%S\"", need_sep ? ",\n" : "",
-                                 desc);
+               fix_escape_fprintf(fp, &buf, "%s\t\"BriefDescription\": \"%S\"",
+                                  need_sep ? ",\n" : "",
+                                  desc);
                need_sep = true;
        }
        if (long_desc) {
-               fix_escape_printf(&buf, "%s\t\"PublicDescription\": \"%S\"", need_sep ? ",\n" : "",
-                                 long_desc);
+               fix_escape_fprintf(fp, &buf, "%s\t\"PublicDescription\": \"%S\"",
+                                  need_sep ? ",\n" : "",
+                                  long_desc);
                need_sep = true;
        }
-       printf("%s}", need_sep ? "\n" : "");
+       fprintf(fp, "%s}", need_sep ? "\n" : "");
        strbuf_release(&buf);
 }
 
@@ -449,8 +482,12 @@ static bool default_skip_duplicate_pmus(void *ps)
 int cmd_list(int argc, const char **argv)
 {
        int i, ret = 0;
-       struct print_state default_ps = {};
-       struct print_state json_ps = {};
+       struct print_state default_ps = {
+               .fp = stdout,
+       };
+       struct print_state json_ps = {
+               .fp = stdout,
+       };
        void *ps = &default_ps;
        struct print_callbacks print_cb = {
                .print_start = default_print_start,
@@ -461,6 +498,7 @@ int cmd_list(int argc, const char **argv)
        };
        const char *cputype = NULL;
        const char *unit_name = NULL;
+       const char *output_path = NULL;
        bool json = false;
        struct option list_options[] = {
                OPT_BOOLEAN(0, "raw-dump", &default_ps.name_only, "Dump raw events"),
@@ -471,6 +509,7 @@ int cmd_list(int argc, const char **argv)
                            "Print longer event descriptions."),
                OPT_BOOLEAN(0, "details", &default_ps.detailed,
                            "Print information on the perf event names and expressions used internally by events."),
+               OPT_STRING('o', "output", &output_path, "file", "output file name"),
                OPT_BOOLEAN(0, "deprecated", &default_ps.deprecated,
                            "Print deprecated events."),
                OPT_STRING(0, "cputype", &cputype, "cpu type",
@@ -497,6 +536,11 @@ int cmd_list(int argc, const char **argv)
        argc = parse_options(argc, argv, list_options, list_usage,
                             PARSE_OPT_STOP_AT_NON_OPTION);
 
+       if (output_path) {
+               default_ps.fp = fopen(output_path, "w");
+               json_ps.fp = default_ps.fp;
+       }
+
        setup_pager();
 
        if (!default_ps.name_only)
@@ -618,5 +662,8 @@ out:
        free(default_ps.last_topic);
        free(default_ps.last_metricgroups);
        strlist__delete(default_ps.visited_metrics);
+       if (output_path)
+               fclose(default_ps.fp);
+
        return ret;
 }