diff options
Diffstat (limited to 'tools/perf/builtin-top.c')
| -rw-r--r-- | tools/perf/builtin-top.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c index 6da30a140e8..1f8c97d5c32 100644 --- a/tools/perf/builtin-top.c +++ b/tools/perf/builtin-top.c @@ -65,6 +65,7 @@ static int group = 0; static unsigned int page_size; static unsigned int mmap_pages = 16; static int freq = 0; +static int verbose = 0; static char *sym_filter; static unsigned long filter_start; @@ -550,11 +551,12 @@ try_again: if (fd[i][counter] < 0) { int err = errno; - error("sys_perf_counter_open() syscall returned with %d (%s)\n", - fd[i][counter], strerror(err)); + if (verbose) + error("sys_perf_counter_open() syscall returned with %d (%s)\n", + fd[i][counter], strerror(err)); if (err == EPERM) - die(" No permission - are you root?\n"); + die("No permission - are you root?\n"); /* * If it's cycles then fall back to hrtimer * based cpu-clock-tick sw counter, which @@ -563,7 +565,9 @@ try_again: if (attr->type == PERF_TYPE_HARDWARE && attr->config == PERF_COUNT_CPU_CYCLES) { - warning(" ... trying to fall back to cpu-clock-ticks\n"); + if (verbose) + warning(" ... trying to fall back to cpu-clock-ticks\n"); + attr->type = PERF_TYPE_SOFTWARE; attr->config = PERF_COUNT_CPU_CLOCK; goto try_again; @@ -673,6 +677,8 @@ static const struct option options[] = { "profile at this frequency"), OPT_INTEGER('E', "entries", &print_entries, "display this many functions"), + OPT_BOOLEAN('v', "verbose", &verbose, + "be more verbose (show counter open errors, etc)"), OPT_END() }; |