perf tools: Show better error message in case we fail to open counters due to EBUSY error (63914aca) · Commits · 戴 / test

Showing better error message in case we fail to open counters due to the EBUSY error. If we detect oprofile daemon process running, we now display following message for EBUSY error: $ perf record ls Error: The PMU counters are busy/taken by another profiler. We found oprofile daemon running, please stop it and try again. In case oprofiled was not detected the current error message stays: $ perf record ls Error: The sys_perf_event_open() syscall returned with 16 (Device or resource busy) for event (cycles). /bin/dmesg may provide additional information. No CONFIG_PERF_EVENTS=y kernel support configured? Also changing PERF_FLAG_FD_CLOEXEC detection code not to display error in case of EBUSY error, as it currently does: $ perf record ls Error: perf_event_open(..., PERF_FLAG_FD_CLOEXEC) failed with unexpected error 16 (Device or resource busy) perf_event_open(..., 0) failed unexpectedly with error 16 (Device or resource busy) The PMU counters are busy/taken by another profiler. We found oprofile daemon running, please stop it and try again. Signed-off-by:

Jiri Olsa <jolsa@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Namhyung Kim <namhyung@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: William Cohen <wcohen@redhat.com> Cc: Yann Droneaud <ydroneaud@opteya.com> Link: http://lkml.kernel.org/r/1406908014-8312-1-git-send-email-jolsa@kernel.org Signed-off-by:

Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/cloexec.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -25,7 +25,7 @@ static int perf_flag_probe(void)
		return 1;
		}

		WARN_ONCE(err != EINVAL,
		WARN_ONCE(err != EINVAL && err != EBUSY,
		"perf_event_open(..., PERF_FLAG_FD_CLOEXEC) failed with unexpected error %d (%s)\n",
		err, strerror(err));

		@@ -33,7 +33,7 @@ static int perf_flag_probe(void)
		fd = sys_perf_event_open(&attr, 0, -1, -1, 0);
		err = errno;

		if (WARN_ONCE(fd < 0,
		if (WARN_ONCE(fd < 0 && err != EBUSY,
		"perf_event_open(..., 0) failed unexpectedly with error %d (%s)\n",
		err, strerror(err)))
		return -1;

tools/perf/util/evsel.c

+6 −0

Original line number	Diff line number	Diff line
		@@ -2039,6 +2039,12 @@ int perf_evsel__open_strerror(struct perf_evsel evsel, struct target target,
		"No APIC? If so then you can boot the kernel with the \"lapic\" boot parameter to force-enable it.");
		#endif
		break;
		case EBUSY:
		if (find_process("oprofiled"))
		return scnprintf(msg, size,
		"The PMU counters are busy/taken by another profiler.\n"
		"We found oprofile daemon running, please stop it and try again.");
		break;
		default:
		break;
		}

tools/perf/util/util.c

+36 −0

Original line number	Diff line number	Diff line
		@@ -536,3 +536,39 @@ void mem_bswap_64(void *src, int byte_size)
		++m;
		}
		}

		bool find_process(const char *name)
		{
		size_t len = strlen(name);
		DIR *dir;
		struct dirent *d;
		int ret = -1;

		dir = opendir(procfs__mountpoint());
		if (!dir)
		return -1;

		/* Walk through the directory. */
		while (ret && (d = readdir(dir)) != NULL) {
		char path[PATH_MAX];
		char *data;
		size_t size;

		if ((d->d_type != DT_DIR) \|\|
		!strcmp(".", d->d_name) \|\|
		!strcmp("..", d->d_name))
		continue;

		scnprintf(path, sizeof(path), "%s/%s/comm",
		procfs__mountpoint(), d->d_name);

		if (filename__read_str(path, &data, &size))
		continue;

		ret = strncmp(name, data, len);
		free(data);
		}

		closedir(dir);
		return ret ? false : true;
		}

tools/perf/util/util.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -346,4 +346,5 @@ void mem_bswap_64(void *src, int byte_size);
		void mem_bswap_32(void *src, int byte_size);

		const char *get_filename_for_perf_kvm(void);
		bool find_process(const char *name);
		#endif /* GIT_COMPAT_UTIL_H */

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