X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=tests%2Fperf%2Ffind_event.c;h=aa1c964c399180ce95dc769ce5f1cfa404bc7536;hp=38ac6c139c2edd6a163069e68974f0acc2cd809c;hb=90aa04a116a8be510b9d256b47de6bbb4144fb8b;hpb=9d16b343fb9e781fc8d8fa3c448a3f382306dd33

diff --git a/tests/perf/find_event.c b/tests/perf/find_event.c
index 38ac6c139..aa1c964c3 100644
--- a/tests/perf/find_event.c
+++ b/tests/perf/find_event.c
@@ -5,69 +5,106 @@
  *
  */
 
+#include <errno.h>
 #include <stdio.h>
-#include <perfmon/pfmlib.h>
 #include <string.h>
 
+#include <linux/perf_event.h>
+#include <perfmon/perf_event.h>
+#include <perfmon/pfmlib_perf_event.h>
+
 int main(int argc, char **argv)
 {
-	int ret, i;
-	unsigned int j;
-	pfm_pmu_info_t pinfo;
+	int ret, fd;
+
+	/* pfm query objects */
+	pfm_perf_encode_arg_t pencoder;
+	pfm_event_info_t info;
+
+	/* Perf event object to be populated by libpfm */
+	struct perf_event_attr attr;
 
 	if (argc != 2) {
 		fprintf(stderr, "Usage: %s <pmu counter to find>\n"
 				"ex: %s UNHALTED_REFERENCE_CYCLES\n"
-				"Returns the first occurence it finds with "
+				"Returns the event raw number if found and actionable with"
 				"return code 0.\n"
-				"If not found returns 1, on error returns -1\n",
+				"If not found returns 1,"
+				"If not actionable return 2,"
+				"on error returns 255\n",
 				argv[0], argv[0]);
 		ret = -1;
 		goto end;
 	}
 
-	memset(&pinfo, 0, sizeof(pinfo));
-	pinfo.size = sizeof(pinfo);
+	/* Initialize perf_event_attr. */
+	memset(&attr, 0, sizeof(struct perf_event_attr));
+
+	/* Initialize libpfm encoder structure. */
+	memset(&pencoder, 0, sizeof(pencoder));
+	pencoder.size = sizeof(pfm_perf_encode_arg_t);
+
+	/* Initialize libpfm event info structure. */
+	memset(&info, 0, sizeof(info));
+	info.size = sizeof(info);
+
+	/* Prepare the encoder for query. */
+	pencoder.attr = &attr; /* Set the perf_event_attr pointer. */
+	pencoder.fstr = NULL; /* Not interested by the fully qualified event string. */
 
 	ret = pfm_initialize();
 	if (ret != PFM_SUCCESS) {
 		fprintf(stderr, "Failed to initialise libpfm: %s",
 				pfm_strerror(ret));
-		ret = -1;
+		ret = 255;
+		goto end;
+	}
+
+	ret = pfm_get_os_event_encoding(argv[1],
+			PFM_PLM0 | PFM_PLM1 | PFM_PLM2 | PFM_PLM3,
+			PFM_OS_PERF_EVENT, &pencoder);
+	if (ret != PFM_SUCCESS) {
+		fprintf(stderr, "libpfm: error pfm_get_os_event_encoding: %s\n",
+				pfm_strerror(ret));
+		ret = 1;
+		goto end;
+	}
+
+	/*
+	 * Query the raw code for later use. Do it now to simplify error
+	 * management.
+	 */
+	ret = pfm_get_event_info(pencoder.idx, PFM_OS_NONE, &info);
+	if (ret != PFM_SUCCESS) {
+		fprintf(stderr, "libpfm: error pfm_get_event_info: %s\n", pfm_strerror(ret));
+		ret = 1;
 		goto end;
 	}
 
-	pfm_for_all_pmus(j) {
-		ret = pfm_get_pmu_info(j, &pinfo);
-		if (ret != PFM_SUCCESS) {
-			continue;
-		}
-
-		for (i = pinfo.first_event; i != -1; i = pfm_get_event_next(i)) {
-			pfm_event_info_t info =
-					{ .size = sizeof(pfm_event_info_t) };
-
-			ret = pfm_get_event_info(i, PFM_OS_NONE, &info);
-			if (ret != PFM_SUCCESS) {
-				fprintf(stderr, "Cannot get event info: %s\n",
-						pfm_strerror(ret));
-				ret = -1;
-				goto end;
-			}
-
-			if (info.pmu != j) {
-				continue;
-			}
-
-			if (strcmp(info.name, argv[1]) == 0) {
-				fprintf(stdout, "r%" PRIx64 "\n", info.code);
-				ret = 0;
-				goto end;
-			}
-		}
+	/*
+	 * Now that the event is found, try to use it to validate that
+	 * the current user has access to it and that it can be used on that
+	 * host.
+	 */
+
+	/* Set the event to disabled to prevent unnecessary side effects. */
+	pencoder.attr->disabled = 1;
+
+	/* perf_event_open is provided by perfmon/perf_event.h. */
+	fd = perf_event_open(pencoder.attr, 0, -1, -1, 0);
+	if (fd == -1) {
+		fprintf(stderr, "perf: error perf_event_open: %d: %s\n", errno,
+				strerror(errno));
+		ret = 2;
+		goto end;
 	}
 
-	ret = 1;
+	/* We close the fd immediately since the event is actionable. */
+	close(fd);
+
+	/* Output the raw code for the event */
+	fprintf(stdout, "r%" PRIx64 "\n", info.code);
+	ret = 0;
 
 end:
 	return ret;