[PATCH v7 1/4] tools/perf: support parsing parameterized events

From: Sukadev Bhattiprolu
Date: Wed Jan 07 2015 - 20:15:41 EST


From: Cody P Schafer <cody@xxxxxxxxxxxxxxxxxx>

Enable event specification like:

pmu/event_name,param1=0x1,param2=0x4/

Assuming that

/sys/bus/event_source/devices/pmu/events/event_name

Contains something like

param2=?,bar=1,param1=?

CC: Haren Myneni <hbabu@xxxxxxxxxx>
CC: Cody P Schafer <dev@xxxxxxxxxx>
Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Signed-off-by: Sukadev Bhattiprolu <sukadev@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Cody P Schafer <cody@xxxxxxxxxxxxxxxxxx>
---
Changelog[v6]:
[Jiri Olsa] Add a check to make sure that sysfs entries have with
parameters exactly match '=?'.

Changelog[v4]:
[Jiri Olsa] Merge to recent perf-core and fix a small conflict.

Changelog[v3]:
[Jiri Olsa] If the sysfs event file specifies 'param=val', make the
usage 'hv_24x7/event,param=123/' rather than 'hv_24x7/event,val=123/'.

tools/perf/util/parse-events.h | 1 +
tools/perf/util/pmu.c | 74 +++++++++++++++++++++++++++++++++++-------
2 files changed, 64 insertions(+), 11 deletions(-)

diff --git a/tools/perf/util/parse-events.h b/tools/perf/util/parse-events.h
index db2cf78..ca226ce 100644
--- a/tools/perf/util/parse-events.h
+++ b/tools/perf/util/parse-events.h
@@ -71,6 +71,7 @@ struct parse_events_term {
int type_val;
int type_term;
struct list_head list;
+ bool used;
};

struct parse_events_evlist {
diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index 5c9c494..bfbecf7 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -551,31 +551,68 @@ static void pmu_format_value(unsigned long *format, __u64 value, __u64 *v,
}

/*
+ * Term is a string term, and might be a param-term. Try to look up it's value
+ * in the remaining terms.
+ * - We have a term like "base-or-format-term=param-term",
+ * - We need to find the value supplied for "param-term" (with param-term named
+ * in a config string) later on in the term list.
+ */
+static int pmu_resolve_param_term(struct parse_events_term *term,
+ struct list_head *head_terms,
+ __u64 *value)
+{
+ struct parse_events_term *t;
+
+ list_for_each_entry(t, head_terms, list) {
+ if (t->type_val == PARSE_EVENTS__TERM_TYPE_NUM) {
+ if (!strcmp(t->config, term->config)) {
+ t->used = true;
+ *value = t->val.num;
+ return 0;
+ }
+ }
+ }
+
+ if (verbose)
+ printf("Required parameter '%s' not specified\n", term->config);
+
+ return -1;
+}
+
+/*
* Setup one of config[12] attr members based on the
* user input data - term parameter.
*/
static int pmu_config_term(struct list_head *formats,
struct perf_event_attr *attr,
struct parse_events_term *term,
+ struct list_head *head_terms,
bool zero)
{
struct perf_pmu_format *format;
__u64 *vp;
+ __u64 val;
+
+ /*
+ * If this is a parameter we've already used for parameterized-eval,
+ * skip it in normal eval.
+ */
+ if (term->used)
+ return 0;

/*
- * Support only for hardcoded and numnerial terms.
* Hardcoded terms should be already in, so nothing
* to be done for them.
*/
if (parse_events__is_hardcoded_term(term))
return 0;

- if (term->type_val != PARSE_EVENTS__TERM_TYPE_NUM)
- return -EINVAL;
-
format = pmu_find_format(formats, term->config);
- if (!format)
+ if (!format) {
+ if (verbose)
+ printf("Invalid event/parameter '%s'\n", term->config);
return -EINVAL;
+ }

switch (format->value) {
case PERF_PMU_FORMAT_VALUE_CONFIG:
@@ -592,11 +629,25 @@ static int pmu_config_term(struct list_head *formats,
}

/*
- * XXX If we ever decide to go with string values for
- * non-hardcoded terms, here's the place to translate
- * them into value.
+ * Either directly use a numeric term, or try to translate string terms
+ * using event parameters.
*/
- pmu_format_value(format->bits, term->val.num, vp, zero);
+ if (term->type_val == PARSE_EVENTS__TERM_TYPE_NUM)
+ val = term->val.num;
+ else if (term->type_val == PARSE_EVENTS__TERM_TYPE_STR) {
+ if (strcmp(term->val.str, "?")) {
+ if (verbose)
+ pr_info("Invalid sysfs entry %s=%s\n",
+ term->config, term->val.str);
+ return -EINVAL;
+ }
+
+ if (pmu_resolve_param_term(term, head_terms, &val))
+ return -EINVAL;
+ } else
+ return -EINVAL;
+
+ pmu_format_value(format->bits, val, vp, zero);
return 0;
}

@@ -607,9 +658,10 @@ int perf_pmu__config_terms(struct list_head *formats,
{
struct parse_events_term *term;

- list_for_each_entry(term, head_terms, list)
- if (pmu_config_term(formats, attr, term, zero))
+ list_for_each_entry(term, head_terms, list) {
+ if (pmu_config_term(formats, attr, term, head_terms, zero))
return -EINVAL;
+ }

return 0;
}
--
1.8.3.1

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