Re: Specifying some processes to record using perf

From: David Ahern
Date: Sat Feb 04 2012 - 18:20:06 EST

On 02/02/2012 09:33 AM, David Ahern wrote:
>
> On 02/02/2012 08:52 AM, Jean-Michel Hautbois wrote:
>> Hi all,
>>
>> I am using perf and I have several process and threads to record.
>> I know that some threads in particular are interesting, and I don't
>> find a way to specify multiple threads in perf record.
>> The "-t" option takes only one thread IIUC.

Found some time on the plane ride home to give this a shot. The attached
applies on top of the perf/core branch in:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git

You can specify multiple threads or multiple processing using a
comma-separated list. e.g., -t tid1,tid2,... or -p pid1,pid2,... (not both).

It still needs more testing, but let me know how it works for what you need.

Arnaldo: would you mind scanning this and see if there are any major
problems/objections with the approach?

David


diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt
index ff9a66e..a5766b4 100644
--- a/tools/perf/Documentation/perf-record.txt
+++ b/tools/perf/Documentation/perf-record.txt
@@ -52,11 +52,11 @@ OPTIONS

-p::
--pid=::
- Record events on existing process ID.
+ Record events on existing process ID (comma separated list).

-t::
--tid=::
- Record events on existing thread ID.
+ Record events on existing thread ID (comma separated list).

-u::
--uid=::
diff --git a/tools/perf/Documentation/perf-stat.txt b/tools/perf/Documentation/perf-stat.txt
index 8966b9a..2fa173b 100644
--- a/tools/perf/Documentation/perf-stat.txt
+++ b/tools/perf/Documentation/perf-stat.txt
@@ -35,11 +35,11 @@ OPTIONS
child tasks do not inherit counters
-p::
--pid=<pid>::
- stat events on existing process id
+ stat events on existing process id (comma separated list)

-t::
--tid=<tid>::
- stat events on existing thread id
+ stat events on existing thread id (comma separated list)


-a::
diff --git a/tools/perf/Documentation/perf-top.txt b/tools/perf/Documentation/perf-top.txt
index ab1454e..4a5680c 100644
--- a/tools/perf/Documentation/perf-top.txt
+++ b/tools/perf/Documentation/perf-top.txt
@@ -72,11 +72,11 @@ Default is to monitor all CPUS.

-p <pid>::
--pid=<pid>::
- Profile events on existing Process ID.
+ Profile events on existing Process ID (comma separated list).

-t <tid>::
--tid=<tid>::
- Profile events on existing thread ID.
+ Profile events on existing thread ID (comma separated list).

-u::
--uid=::
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 32870ee..3c1b6c7 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -655,8 +655,6 @@ static const char * const record_usage[] = {
*/
static struct perf_record record = {
.opts = {
- .target_pid = -1,
- .target_tid = -1,
.mmap_pages = UINT_MAX,
.user_freq = UINT_MAX,
.user_interval = ULLONG_MAX,
@@ -680,9 +678,9 @@ const struct option record_options[] = {
parse_events_option),
OPT_CALLBACK(0, "filter", &record.evlist, "filter",
"event filter", parse_filter),
- OPT_INTEGER('p', "pid", &record.opts.target_pid,
+ OPT_STRING('p', "pid", &record.opts.target_pid, "pid",
"record events on existing process id"),
- OPT_INTEGER('t', "tid", &record.opts.target_tid,
+ OPT_STRING('t', "tid", &record.opts.target_tid, "tid",
"record events on existing thread id"),
OPT_INTEGER('r', "realtime", &record.realtime_prio,
"collect data with this RT SCHED_FIFO priority"),
@@ -749,7 +747,7 @@ int cmd_record(int argc, const char **argv, const char *prefix __used)

argc = parse_options(argc, argv, record_options, record_usage,
PARSE_OPT_STOP_AT_NON_OPTION);
- if (!argc && rec->opts.target_pid == -1 && rec->opts.target_tid == -1 &&
+ if (!argc && !rec->opts.target_pid && !rec->opts.target_tid &&
!rec->opts.system_wide && !rec->opts.cpu_list && !rec->uid_str)
usage_with_options(record_usage, record_options);

@@ -795,7 +793,7 @@ int cmd_record(int argc, const char **argv, const char *prefix __used)
if (rec->uid_str != NULL && rec->opts.uid == UINT_MAX - 1)
goto out_free_fd;

- if (rec->opts.target_pid != -1)
+ if (rec->opts.target_pid)
rec->opts.target_tid = rec->opts.target_pid;

if (perf_evlist__create_maps(evsel_list, rec->opts.target_pid,
diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 459b862..da9db2c 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -182,8 +182,8 @@ static int run_count = 1;
static bool no_inherit = false;
static bool scale = true;
static bool no_aggr = false;
-static pid_t target_pid = -1;
-static pid_t target_tid = -1;
+static const char *target_pid;
+static const char *target_tid;
static pid_t child_pid = -1;
static bool null_run = false;
static int detailed_run = 0;
@@ -296,7 +296,7 @@ static int create_perf_stat_counter(struct perf_evsel *evsel,
if (system_wide)
return perf_evsel__open_per_cpu(evsel, evsel_list->cpus,
group, group_fd);
- if (target_pid == -1 && target_tid == -1) {
+ if (!target_pid && !target_tid) {
attr->disabled = 1;
attr->enable_on_exec = 1;
}
@@ -446,7 +446,7 @@ static int run_perf_stat(int argc __used, const char **argv)
exit(-1);
}

- if (target_tid == -1 && target_pid == -1 && !system_wide)
+ if (!target_tid && !target_pid && !system_wide)
evsel_list->threads->map[0] = child_pid;

/*
@@ -960,14 +960,14 @@ static void print_stat(int argc, const char **argv)
if (!csv_output) {
fprintf(output, "\n");
fprintf(output, " Performance counter stats for ");
- if(target_pid == -1 && target_tid == -1) {
+ if (!target_pid && !target_tid) {
fprintf(output, "\'%s", argv[0]);
for (i = 1; i < argc; i++)
fprintf(output, " %s", argv[i]);
- } else if (target_pid != -1)
- fprintf(output, "process id \'%d", target_pid);
+ } else if (target_pid)
+ fprintf(output, "process id \'%s", target_pid);
else
- fprintf(output, "thread id \'%d", target_tid);
+ fprintf(output, "thread id \'%s", target_tid);

fprintf(output, "\'");
if (run_count > 1)
@@ -1041,10 +1041,10 @@ static const struct option options[] = {
"event filter", parse_filter),
OPT_BOOLEAN('i', "no-inherit", &no_inherit,
"child tasks do not inherit counters"),
- OPT_INTEGER('p', "pid", &target_pid,
- "stat events on existing process id"),
- OPT_INTEGER('t', "tid", &target_tid,
- "stat events on existing thread id"),
+ OPT_STRING('p', "pid", &target_pid, "pid",
+ "stat events on existing process id"),
+ OPT_STRING('t', "tid", &target_tid, "tid",
+ "stat events on existing thread id"),
OPT_BOOLEAN('a', "all-cpus", &system_wide,
"system-wide collection from all CPUs"),
OPT_BOOLEAN('g', "group", &group,
@@ -1182,7 +1182,7 @@ int cmd_stat(int argc, const char **argv, const char *prefix __used)
} else if (big_num_opt == 0) /* User passed --no-big-num */
big_num = false;

- if (!argc && target_pid == -1 && target_tid == -1)
+ if (!argc && !target_pid && !target_tid)
usage_with_options(stat_usage, options);
if (run_count <= 0)
usage_with_options(stat_usage, options);
@@ -1198,7 +1198,7 @@ int cmd_stat(int argc, const char **argv, const char *prefix __used)
if (add_default_attributes())
goto out;

- if (target_pid != -1)
+ if (target_pid)
target_tid = target_pid;

evsel_list->threads = thread_map__new(target_pid, target_tid, UINT_MAX);
diff --git a/tools/perf/builtin-test.c b/tools/perf/builtin-test.c
index 70c4eb2..23ac482 100644
--- a/tools/perf/builtin-test.c
+++ b/tools/perf/builtin-test.c
@@ -264,6 +264,20 @@ static int trace_event__id(const char *evname)
return err;
}

+static struct thread_map *test__thread_map(void)
+{
+ struct thread_map *threads;
+ char pidstr[16];
+
+ sprintf(pidstr, "%d", getpid());
+ threads = thread_map__new(NULL, pidstr, UINT_MAX);
+
+ if (threads == NULL)
+ pr_debug("thread_map__new\n");
+
+ return threads;
+}
+
static int test__open_syscall_event(void)
{
int err = -1, fd;
@@ -278,11 +292,9 @@ static int test__open_syscall_event(void)
return -1;
}

- threads = thread_map__new(-1, getpid(), UINT_MAX);
- if (threads == NULL) {
- pr_debug("thread_map__new\n");
+ threads = test__thread_map();
+ if (threads == NULL)
return -1;
- }

memset(&attr, 0, sizeof(attr));
attr.type = PERF_TYPE_TRACEPOINT;
@@ -344,11 +356,9 @@ static int test__open_syscall_event_on_all_cpus(void)
return -1;
}

- threads = thread_map__new(-1, getpid(), UINT_MAX);
- if (threads == NULL) {
- pr_debug("thread_map__new\n");
+ threads = test__thread_map();
+ if (threads == NULL)
return -1;
- }

cpus = cpu_map__new(NULL);
if (cpus == NULL) {
@@ -492,11 +502,9 @@ static int test__basic_mmap(void)
expected_nr_events[i] = random() % 257;
}

- threads = thread_map__new(-1, getpid(), UINT_MAX);
- if (threads == NULL) {
- pr_debug("thread_map__new\n");
+ threads = test__thread_map();
+ if (threads == NULL)
return -1;
- }

cpus = cpu_map__new(NULL);
if (cpus == NULL) {
@@ -1010,8 +1018,6 @@ realloc:
static int test__PERF_RECORD(void)
{
struct perf_record_opts opts = {
- .target_pid = -1,
- .target_tid = -1,
.no_delay = true,
.freq = 10,
.mmap_pages = 256,
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index d869b21..94d55cb 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -965,7 +965,7 @@ static int __cmd_top(struct perf_top *top)
if (ret)
goto out_delete;

- if (top->target_tid != -1 || top->uid != UINT_MAX)
+ if (top->target_tid || top->uid != UINT_MAX)
perf_event__synthesize_thread_map(&top->tool, top->evlist->threads,
perf_event__process,
&top->session->host_machine);
@@ -1103,8 +1103,6 @@ int cmd_top(int argc, const char **argv, const char *prefix __used)
struct perf_top top = {
.count_filter = 5,
.delay_secs = 2,
- .target_pid = -1,
- .target_tid = -1,
.uid = UINT_MAX,
.freq = 1000, /* 1 KHz */
.sample_id_all_avail = true,
@@ -1118,9 +1116,9 @@ int cmd_top(int argc, const char **argv, const char *prefix __used)
parse_events_option),
OPT_INTEGER('c', "count", &top.default_interval,
"event period to sample"),
- OPT_INTEGER('p', "pid", &top.target_pid,
+ OPT_STRING('p', "pid", &top.target_pid, "pid",
"profile events on existing process id"),
- OPT_INTEGER('t', "tid", &top.target_tid,
+ OPT_STRING('t', "tid", &top.target_tid, "tid",
"profile events on existing thread id"),
OPT_BOOLEAN('a', "all-cpus", &top.system_wide,
"system-wide collection from all CPUs"),
@@ -1210,13 +1208,13 @@ int cmd_top(int argc, const char **argv, const char *prefix __used)
goto out_delete_evlist;

/* CPU and PID are mutually exclusive */
- if (top.target_tid > 0 && top.cpu_list) {
+ if (top.target_tid && top.cpu_list) {
printf("WARNING: PID switch overriding CPU\n");
sleep(1);
top.cpu_list = NULL;
}

- if (top.target_pid != -1)
+ if (top.target_pid)
top.target_tid = top.target_pid;

if (perf_evlist__create_maps(top.evlist, top.target_pid,
diff --git a/tools/perf/perf.h b/tools/perf/perf.h
index 92af168..deb17db 100644
--- a/tools/perf/perf.h
+++ b/tools/perf/perf.h
@@ -186,8 +186,8 @@ extern const char perf_version_string[];
void pthread__unblock_sigwinch(void);

struct perf_record_opts {
- pid_t target_pid;
- pid_t target_tid;
+ const char *target_pid;
+ const char *target_tid;
uid_t uid;
bool call_graph;
bool group;
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index a6d50e3..cfe273f 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -593,15 +593,15 @@ int perf_evlist__mmap(struct perf_evlist *evlist, unsigned int pages,
return perf_evlist__mmap_per_cpu(evlist, prot, mask);
}

-int perf_evlist__create_maps(struct perf_evlist *evlist, pid_t target_pid,
- pid_t target_tid, uid_t uid, const char *cpu_list)
+int perf_evlist__create_maps(struct perf_evlist *evlist, const char *target_pid,
+ const char *target_tid, uid_t uid, const char *cpu_list)
{
evlist->threads = thread_map__new(target_pid, target_tid, uid);

if (evlist->threads == NULL)
return -1;

- if (uid != UINT_MAX || (cpu_list == NULL && target_tid != -1))
+ if (uid != UINT_MAX || (cpu_list == NULL && target_tid))
evlist->cpus = cpu_map__dummy_new();
else
evlist->cpus = cpu_map__new(cpu_list);
@@ -820,7 +820,7 @@ int perf_evlist__prepare_workload(struct perf_evlist *evlist,
exit(-1);
}

- if (!opts->system_wide && opts->target_tid == -1 && opts->target_pid == -1)
+ if (!opts->system_wide && !opts->target_tid && !opts->target_pid)
evlist->threads->map[0] = evlist->workload.pid;

close(child_ready_pipe[1]);
diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
index 9c51660..666745a 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -106,8 +106,8 @@ static inline void perf_evlist__set_maps(struct perf_evlist *evlist,
evlist->threads = threads;
}

-int perf_evlist__create_maps(struct perf_evlist *evlist, pid_t target_pid,
- pid_t tid, uid_t uid, const char *cpu_list);
+int perf_evlist__create_maps(struct perf_evlist *evlist, const char *target_pid,
+ const char *tid, uid_t uid, const char *cpu_list);
void perf_evlist__delete_maps(struct perf_evlist *evlist);
int perf_evlist__set_filters(struct perf_evlist *evlist);

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index dcfefab..6c568d2 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -130,7 +130,7 @@ void perf_evsel__config(struct perf_evsel *evsel, struct perf_record_opts *opts)
attr->mmap = track;
attr->comm = track;

- if (opts->target_pid == -1 && opts->target_tid == -1 && !opts->system_wide) {
+ if (!opts->target_pid && !opts->target_tid && !opts->system_wide) {
attr->disabled = 1;
attr->enable_on_exec = 1;
}
diff --git a/tools/perf/util/python.c b/tools/perf/util/python.c
index e03b58a..867948f 100644
--- a/tools/perf/util/python.c
+++ b/tools/perf/util/python.c
@@ -426,9 +426,10 @@ static int pyrf_thread_map__init(struct pyrf_thread_map *pthreads,
PyObject *args, PyObject *kwargs)
{
static char *kwlist[] = { "pid", "tid", "uid", NULL };
- int pid = -1, tid = -1, uid = UINT_MAX;
+ char *pid = NULL, *tid = NULL;
+ int uid = UINT_MAX;

- if (!PyArg_ParseTupleAndKeywords(args, kwargs, "|iii",
+ if (!PyArg_ParseTupleAndKeywords(args, kwargs, "|ssi",
kwlist, &pid, &tid, &uid))
return -1;

diff --git a/tools/perf/util/thread_map.c b/tools/perf/util/thread_map.c
index 3d4b6c5..e629df2 100644
--- a/tools/perf/util/thread_map.c
+++ b/tools/perf/util/thread_map.c
@@ -6,7 +6,10 @@
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
+#include <ctype.h>
+#include <string.h>
#include "thread_map.h"
+#include "debug.h"

/* Skip "." and ".." directories */
static int filter(const struct dirent *dir)
@@ -17,46 +20,134 @@ static int filter(const struct dirent *dir)
return 1;
}

-struct thread_map *thread_map__new_by_pid(pid_t pid)
+static pid_t get_next_task_id(char **str)
{
- struct thread_map *threads;
+ char *p, *pend;
+ pid_t ret = -1;
+
+ pend = p = *str;
+
+ /* only expecting digits separated by commas */
+ while (isdigit(*pend))
+ ++pend;
+
+ if (*pend == ',') {
+ *pend = '\0';
+ pend++;
+
+ /* catch strings ending in a comma - like '1234,' */
+ if (*pend == '\0') {
+ ui__error("task id strings should not end in a comma\n");
+ goto out;
+ }
+ }
+
+ /* only convert if all characters are valid */
+ if (*pend == '\0') {
+ ret = atoi(p);
+ *str = pend;
+ }
+
+out:
+ return ret;
+}
+
+static struct thread_map *thread_map__new_by_pid(const char *pid_str)
+{
+ struct thread_map *threads = NULL;
char name[256];
- int items;
+ int items, total_tasks = 0;
struct dirent **namelist = NULL;
- int i;
+ int i, j = 0;
+ char *ostr, *str;
+ pid_t pid;

- sprintf(name, "/proc/%d/task", pid);
- items = scandir(name, &namelist, filter, NULL);
- if (items <= 0)
+ ostr = strdup(pid_str);
+ if (!ostr)
return NULL;
+ str = ostr;
+
+ while(*str) {
+ pid = get_next_task_id(&str);
+ if (pid < 0) {
+ free(threads);
+ threads = NULL;
+ break;
+ }

- threads = malloc(sizeof(*threads) + sizeof(pid_t) * items);
- if (threads != NULL) {
- for (i = 0; i < items; i++)
- threads->map[i] = atoi(namelist[i]->d_name);
- threads->nr = items;
+ sprintf(name, "/proc/%d/task", pid);
+ items = scandir(name, &namelist, filter, NULL);
+ if (items <= 0)
+ break;
+
+ total_tasks += items;
+ if (threads)
+ threads = realloc(threads, sizeof(*threads) + sizeof(pid_t) * total_tasks);
+ else
+ threads = malloc(sizeof(*threads) + sizeof(pid_t) * items);
+
+ if (threads != NULL) {
+ for (i = 0; i < items; i++)
+ threads->map[j++] = atoi(namelist[i]->d_name);
+ threads->nr = total_tasks;
+ }
+
+ for (i=0; i<items; i++)
+ free(namelist[i]);
+ free(namelist);
+
+ if (!threads)
+ break;
}

- for (i=0; i<items; i++)
- free(namelist[i]);
- free(namelist);
+ free(ostr);

return threads;
}

-struct thread_map *thread_map__new_by_tid(pid_t tid)
+static struct thread_map *thread_map__new_by_tid(const char *tid_str)
{
- struct thread_map *threads = malloc(sizeof(*threads) + sizeof(pid_t));
-
- if (threads != NULL) {
- threads->map[0] = tid;
+ struct thread_map *threads = NULL;
+ char *str;
+ int ntasks = 0;
+ pid_t tid;
+
+ if (!tid_str) {
+ threads = malloc(sizeof(*threads) + sizeof(pid_t));
+ threads->map[1] = -1;
threads->nr = 1;
+ return threads;
+ }
+
+ str = strdup(tid_str);
+ if (!str)
+ return NULL;
+
+ while(*str) {
+ tid = get_next_task_id(&str);
+ if (tid < 0) {
+ free(threads);
+ threads = NULL;
+ break;
+ }
+
+ ntasks++;
+ if (threads)
+ threads = realloc(threads, sizeof(*threads) + sizeof(pid_t) * ntasks);
+ else
+ threads = malloc(sizeof(*threads) + sizeof(pid_t));
+
+ if (threads == NULL)
+ break;
+
+ threads->map[ntasks-1] = tid;
+ threads->nr = ntasks;
}

return threads;
}

-struct thread_map *thread_map__new_by_uid(uid_t uid)
+static struct thread_map *thread_map__new_by_uid(uid_t uid)
{
DIR *proc;
int max_threads = 32, items, i;
@@ -141,12 +232,12 @@ out_free_closedir:
goto out_closedir;
}

-struct thread_map *thread_map__new(pid_t pid, pid_t tid, uid_t uid)
+struct thread_map *thread_map__new(const char *pid, const char *tid, uid_t uid)
{
- if (pid != -1)
+ if (pid)
return thread_map__new_by_pid(pid);

- if (tid == -1 && uid != UINT_MAX)
+ if (!tid && uid != UINT_MAX)
return thread_map__new_by_uid(uid);

return thread_map__new_by_tid(tid);
diff --git a/tools/perf/util/thread_map.h b/tools/perf/util/thread_map.h
index c75ddba..b067114 100644
--- a/tools/perf/util/thread_map.h
+++ b/tools/perf/util/thread_map.h
@@ -9,10 +9,7 @@ struct thread_map {
int map[];
};

-struct thread_map *thread_map__new_by_pid(pid_t pid);
-struct thread_map *thread_map__new_by_tid(pid_t tid);
-struct thread_map *thread_map__new_by_uid(uid_t uid);
-struct thread_map *thread_map__new(pid_t pid, pid_t tid, uid_t uid);
+struct thread_map *thread_map__new(const char *pid, const char *tid, uid_t uid);
void thread_map__delete(struct thread_map *threads);

size_t thread_map__fprintf(struct thread_map *threads, FILE *fp);
diff --git a/tools/perf/util/top.c b/tools/perf/util/top.c
index e4370ca..09fe579 100644
--- a/tools/perf/util/top.c
+++ b/tools/perf/util/top.c
@@ -69,11 +69,11 @@ size_t perf_top__header_snprintf(struct perf_top *top, char *bf, size_t size)

ret += SNPRINTF(bf + ret, size - ret, "], ");

- if (top->target_pid != -1)
- ret += SNPRINTF(bf + ret, size - ret, " (target_pid: %d",
+ if (top->target_pid)
+ ret += SNPRINTF(bf + ret, size - ret, " (target_pid: %s",
top->target_pid);
- else if (top->target_tid != -1)
- ret += SNPRINTF(bf + ret, size - ret, " (target_tid: %d",
+ else if (top->target_tid)
+ ret += SNPRINTF(bf + ret, size - ret, " (target_tid: %s",
top->target_tid);
else if (top->uid_str != NULL)
ret += SNPRINTF(bf + ret, size - ret, " (uid: %s",
@@ -85,7 +85,7 @@ size_t perf_top__header_snprintf(struct perf_top *top, char *bf, size_t size)
ret += SNPRINTF(bf + ret, size - ret, ", CPU%s: %s)",
top->evlist->cpus->nr > 1 ? "s" : "", top->cpu_list);
else {
- if (top->target_tid != -1)
+ if (top->target_tid)
ret += SNPRINTF(bf + ret, size - ret, ")");
else
ret += SNPRINTF(bf + ret, size - ret, ", %d CPU%s)",
diff --git a/tools/perf/util/top.h b/tools/perf/util/top.h
index def3e53..49eb848 100644
--- a/tools/perf/util/top.h
+++ b/tools/perf/util/top.h
@@ -23,7 +23,7 @@ struct perf_top {
u64 guest_us_samples, guest_kernel_samples;
int print_entries, count_filter, delay_secs;
int freq;
- pid_t target_pid, target_tid;
+ const char *target_pid, *target_tid;
uid_t uid;
bool hide_kernel_symbols, hide_user_symbols, zero;
bool system_wide;
diff --git a/tools/perf/util/usage.c b/tools/perf/util/usage.c
index d0c0139..1240bd6 100644
--- a/tools/perf/util/usage.c
+++ b/tools/perf/util/usage.c
@@ -83,7 +83,7 @@ void warning(const char *warn, ...)
va_end(params);
}

-uid_t parse_target_uid(const char *str, pid_t tid, pid_t pid)
+uid_t parse_target_uid(const char *str, const char *tid, const char *pid)
{
struct passwd pwd, *result;
char buf[1024];
@@ -91,8 +91,8 @@ uid_t parse_target_uid(const char *str, pid_t tid, pid_t pid)
if (str == NULL)
return UINT_MAX;

- /* CPU and PID are mutually exclusive */
- if (tid > 0 || pid > 0) {
+ /* UUID and PID are mutually exclusive */
+ if (tid || pid) {
ui__warning("PID/TID switch overriding UID\n");
sleep(1);
return UINT_MAX;
diff --git a/tools/perf/util/util.h b/tools/perf/util/util.h
index 232d17e..7917b09 100644
--- a/tools/perf/util/util.h
+++ b/tools/perf/util/util.h
@@ -245,7 +245,7 @@ struct perf_event_attr;

void event_attr_init(struct perf_event_attr *attr);

-uid_t parse_target_uid(const char *str, pid_t tid, pid_t pid);
+uid_t parse_target_uid(const char *str, const char *tid, const char *pid);

#define _STR(x) #x
#define STR(x) _STR(x)