Commit 7fbfe22c authored by Arnaldo Carvalho de Melo's avatar Arnaldo Carvalho de Melo
Browse files

perf trace: Filter own pid to avoid a feedback look in 'perf trace record -a' 



When doing a system wide 'perf trace record' we need, just like in 'perf
trace' live mode, to filter out perf trace's own pid, so set up a
tracepoint filter for the raw_syscalls tracepoints right after adding
them to the argv array that is set up to then call cmd_record().

Reported-by: default avatarAndi Kleen <ak@linux.intel.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-uysx5w8f2y5ndoln5cq370tv@git.kernel.org


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent da949f50

tools/perf/builtin-trace.c

+16 −8
Original line number Diff line number Diff line
@@ -2796,21 +2796,23 @@ static int trace__record(struct trace *trace, int argc, const char **argv) 
		"-m", "1024",

		"-c", "1",

	};



	pid_t pid = getpid();

	char *filter = asprintf__tp_filter_pids(1, &pid);

	const char * const sc_args[] = { "-e", };

	unsigned int sc_args_nr = ARRAY_SIZE(sc_args);

	const char * const majpf_args[] = { "-e", "major-faults" };

	unsigned int majpf_args_nr = ARRAY_SIZE(majpf_args);

	const char * const minpf_args[] = { "-e", "minor-faults" };

	unsigned int minpf_args_nr = ARRAY_SIZE(minpf_args);

	int err = -1;



	/* +1 is for the event string below */

	rec_argc = ARRAY_SIZE(record_args) + sc_args_nr + 1 +

	/* +3 is for the event string below and the pid filter */

	rec_argc = ARRAY_SIZE(record_args) + sc_args_nr + 3 +

		majpf_args_nr + minpf_args_nr + argc;

	rec_argv = calloc(rec_argc + 1, sizeof(char *));



	if (rec_argv == NULL)

		return -ENOMEM;

	if (rec_argv == NULL || filter == NULL)

		goto out_free;



	j = 0;

	for (i = 0; i < ARRAY_SIZE(record_args); i++)
@@ -2827,11 +2829,13 @@ static int trace__record(struct trace *trace, int argc, const char **argv) 
			rec_argv[j++] = "syscalls:sys_enter,syscalls:sys_exit";

		else {

			pr_err("Neither raw_syscalls nor syscalls events exist.\n");

			free(rec_argv);

			return -1;

			goto out_free;

		}

	}



	rec_argv[j++] = "--filter";

	rec_argv[j++] = filter;



	if (trace->trace_pgfaults & TRACE_PFMAJ)

		for (i = 0; i < majpf_args_nr; i++)

			rec_argv[j++] = majpf_args[i];
@@ -2843,7 +2847,11 @@ static int trace__record(struct trace *trace, int argc, const char **argv) 
	for (i = 0; i < (unsigned int)argc; i++)

		rec_argv[j++] = argv[i];



	return cmd_record(j, rec_argv);

	err = cmd_record(j, rec_argv);

out_free:

	free(filter);

	free(rec_argv);

	return err;

}



static size_t trace__fprintf_thread_summary(struct trace *trace, FILE *fp);

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