tools/perf/util/s390-sample-raw.c

Source file repositories/reference/linux-study-clean/tools/perf/util/s390-sample-raw.c

File Facts

System
Linux kernel
Corpus path
tools/perf/util/s390-sample-raw.c
Extension
.c
Size
10498 bytes
Lines
378
Domain
Support Tooling And Documentation
Bucket
tools
Inferred role
Support Tooling And Documentation: implementation source
Status
source implementation candidate

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

struct get_counter_name_data {
	long wanted;
	const char *result;
};

static int get_counter_name_callback(void *vdata, struct pmu_event_info *info)
{
	struct get_counter_name_data *data = vdata;
	int rc, event_nr;
	const char *event_str;

	if (info->str == NULL)
		return 0;

	event_str = strstr(info->str, "event=");
	if (!event_str)
		return 0;

	rc = sscanf(event_str, "event=%x", &event_nr);
	if (rc == 1 && event_nr == data->wanted) {
		data->result = info->name;
		return 1; /* Terminate the search. */
	}
	return 0;
}

static size_t get_counter_name_hash_fn(long key, void *ctx __maybe_unused)
{
	return key;
}

static bool get_counter_name_hashmap_equal_fn(long key1, long key2, void *ctx __maybe_unused)
{
	return key1 == key2;
}

/* Scan the PMU and extract the logical name of a counter from the event. Input
 * is the counter set and counter number with in the set. Construct the event
 * number and use this as key. If they match return the name of this counter.
 * If no match is found a NULL pointer is returned.
 */
static char *get_counter_name(int set, int nr, struct perf_pmu *pmu)
{
	static struct hashmap *cache;
	static struct perf_pmu *cache_pmu;
	long cache_key = get_counterset_start(set) + nr;
	struct get_counter_name_data data = {
		.wanted = cache_key,
		.result = NULL,
	};
	char *result = NULL;

	if (!pmu)
		return NULL;

	if (cache_pmu == pmu && hashmap__find(cache, cache_key, &result))
		return strdup(result);

	perf_pmu__for_each_event(pmu, /*skip_duplicate_pmus=*/ true,
				 &data, get_counter_name_callback);

	result = strdup(data.result ?: "<unknown>");

	if (cache_pmu == NULL) {
		struct hashmap *tmp = hashmap__new(get_counter_name_hash_fn,
						   get_counter_name_hashmap_equal_fn,
						   /*ctx=*/NULL);

		if (!IS_ERR(tmp)) {
			cache = tmp;
			cache_pmu = pmu;
		}
	}

	if (cache_pmu == pmu && result) {
		char *old_value = NULL, *new_value = strdup(result);

		if (new_value) {
			hashmap__set(cache, cache_key, new_value, /*old_key=*/NULL, &old_value);
			/*
			 * Free in case of a race, but resizing would be broken
			 * in that case.
			 */
			free(old_value);
		}
	}
	return result;
}

static void s390_cpumcfdg_dump(struct perf_pmu *pmu, struct perf_sample *sample)

Annotation

Implementation Notes