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-rw-r--r--tools/perf/util/record.c43
1 files changed, 38 insertions, 5 deletions
diff --git a/tools/perf/util/record.c b/tools/perf/util/record.c
index 6f09e4962dad..9cfc7bf16531 100644
--- a/tools/perf/util/record.c
+++ b/tools/perf/util/record.c
@@ -5,6 +5,7 @@
#include "parse-events.h"
#include <errno.h>
#include <api/fs/fs.h>
+#include <subcmd/parse-options.h>
#include "util.h"
#include "cloexec.h"
@@ -219,11 +220,21 @@ static int record_opts__config_freq(struct record_opts *opts)
* User specified frequency is over current maximum.
*/
if (user_freq && (max_rate < opts->freq)) {
- pr_err("Maximum frequency rate (%u) reached.\n"
- "Please use -F freq option with lower value or consider\n"
- "tweaking /proc/sys/kernel/perf_event_max_sample_rate.\n",
- max_rate);
- return -1;
+ if (opts->strict_freq) {
+ pr_err("error: Maximum frequency rate (%'u Hz) exceeded.\n"
+ " Please use -F freq option with a lower value or consider\n"
+ " tweaking /proc/sys/kernel/perf_event_max_sample_rate.\n",
+ max_rate);
+ return -1;
+ } else {
+ pr_warning("warning: Maximum frequency rate (%'u Hz) exceeded, throttling from %'u Hz to %'u Hz.\n"
+ " The limit can be raised via /proc/sys/kernel/perf_event_max_sample_rate.\n"
+ " The kernel will lower it when perf's interrupts take too long.\n"
+ " Use --strict-freq to disable this throttling, refusing to record.\n",
+ max_rate, opts->freq, max_rate);
+
+ opts->freq = max_rate;
+ }
}
/*
@@ -291,3 +302,25 @@ out_delete:
perf_evlist__delete(temp_evlist);
return ret;
}
+
+int record__parse_freq(const struct option *opt, const char *str, int unset __maybe_unused)
+{
+ unsigned int freq;
+ struct record_opts *opts = opt->value;
+
+ if (!str)
+ return -EINVAL;
+
+ if (strcasecmp(str, "max") == 0) {
+ if (get_max_rate(&freq)) {
+ pr_err("couldn't read /proc/sys/kernel/perf_event_max_sample_rate\n");
+ return -1;
+ }
+ pr_info("info: Using a maximum frequency rate of %'d Hz\n", freq);
+ } else {
+ freq = atoi(str);
+ }
+
+ opts->user_freq = freq;
+ return 0;
+}