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-rw-r--r--tools/perf/builtin-record.c2
-rw-r--r--tools/perf/builtin-stat.c38
-rw-r--r--tools/perf/builtin-top.c6
3 files changed, 29 insertions, 17 deletions
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 93bd2ff001fb..d9dd47885218 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -326,7 +326,7 @@ try_again:
goto try_again;
}
printf("\n");
- error("perfcounter syscall returned with %d (%s)\n",
+ error("sys_perf_event_open() syscall returned with %d (%s). /bin/dmesg may provide additional information.\n",
fd[nr_cpu][counter][thread_index], strerror(err));
#if defined(__i386__) || defined(__x86_64__)
diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index b3e568ffad27..970a7f2a083d 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -153,9 +153,9 @@ struct stats walltime_nsecs_stats;
attrs[counter].config == PERF_COUNT_##c)
#define ERR_PERF_OPEN \
-"Error: counter %d, sys_perf_event_open() syscall returned with %d (%s)\n"
+"counter %d, sys_perf_event_open() syscall returned with %d (%s). /bin/dmesg may provide additional information."
-static int create_perf_stat_counter(int counter)
+static int create_perf_stat_counter(int counter, bool *perm_err)
{
struct perf_event_attr *attr = attrs + counter;
int thread;
@@ -171,11 +171,14 @@ static int create_perf_stat_counter(int counter)
for (cpu = 0; cpu < nr_cpus; cpu++) {
fd[cpu][counter][0] = sys_perf_event_open(attr,
-1, cpumap[cpu], -1, 0);
- if (fd[cpu][counter][0] < 0)
- pr_debug(ERR_PERF_OPEN, counter,
+ if (fd[cpu][counter][0] < 0) {
+ if (errno == EPERM || errno == EACCES)
+ *perm_err = true;
+ error(ERR_PERF_OPEN, counter,
fd[cpu][counter][0], strerror(errno));
- else
+ } else {
++ncreated;
+ }
}
} else {
attr->inherit = !no_inherit;
@@ -186,12 +189,15 @@ static int create_perf_stat_counter(int counter)
for (thread = 0; thread < thread_num; thread++) {
fd[0][counter][thread] = sys_perf_event_open(attr,
all_tids[thread], -1, -1, 0);
- if (fd[0][counter][thread] < 0)
- pr_debug(ERR_PERF_OPEN, counter,
+ if (fd[0][counter][thread] < 0) {
+ if (errno == EPERM || errno == EACCES)
+ *perm_err = true;
+ error(ERR_PERF_OPEN, counter,
fd[0][counter][thread],
strerror(errno));
- else
+ } else {
++ncreated;
+ }
}
}
@@ -332,6 +338,7 @@ static int run_perf_stat(int argc __used, const char **argv)
int status = 0;
int counter, ncreated = 0;
int child_ready_pipe[2], go_pipe[2];
+ bool perm_err = false;
const bool forks = (argc > 0);
char buf;
@@ -390,12 +397,15 @@ static int run_perf_stat(int argc __used, const char **argv)
}
for (counter = 0; counter < nr_counters; counter++)
- ncreated += create_perf_stat_counter(counter);
-
- if (ncreated == 0) {
- pr_err("No permission to collect %sstats.\n"
- "Consider tweaking /proc/sys/kernel/perf_event_paranoid.\n",
- system_wide ? "system-wide " : "");
+ ncreated += create_perf_stat_counter(counter, &perm_err);
+
+ if (ncreated < nr_counters) {
+ if (perm_err)
+ error("You may not have permission to collect %sstats.\n"
+ "\t Consider tweaking"
+ " /proc/sys/kernel/perf_event_paranoid or running as root.",
+ system_wide ? "system-wide " : "");
+ die("Not all events could be opened.\n");
if (child_pid != -1)
kill(child_pid, SIGTERM);
return -1;
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index dd625808c2a5..3d2b47d5121a 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -1214,7 +1214,9 @@ try_again:
int err = errno;
if (err == EPERM || err == EACCES)
- die("No permission - are you root?\n");
+ die("Permission error - are you root?\n"
+ "\t Consider tweaking"
+ " /proc/sys/kernel/perf_event_paranoid.\n");
/*
* If it's cycles then fall back to hrtimer
* based cpu-clock-tick sw counter, which
@@ -1231,7 +1233,7 @@ try_again:
goto try_again;
}
printf("\n");
- error("perfcounter syscall returned with %d (%s)\n",
+ error("sys_perf_event_open() syscall returned with %d (%s). /bin/dmesg may provide additional information.\n",
fd[i][counter][thread_index], strerror(err));
die("No CONFIG_PERF_EVENTS=y kernel support configured?\n");
exit(-1);
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