simpleperf: avoid warning for default freq.

When max_freq = 1800, and run `simpleperf record -e cpu-cycles -f 1000`,
it prints warning for default freq:
  Sample frequency 4000 is out of range [1, 1800], adjust it to 1800

This patch removes the unproper warning.
Also remove AdjustSampleFrequency() because the freq will
be adjusted in event_fd.cpp.

Bug: http://b/29574526
Test: run `simpleperf record -e cpu-cycles -f 1000`.
Test: run simpleperf_unit_test.
Change-Id: Ieed106fb539b7deb9fee3208f00228c6e0520acb

4 files changed, 8 insertions, 22 deletions

diff --git a/simpleperf/cmd_record.cpp b/simpleperf/cmd_record.cpp
index 7152ab5f..902d2bcb 100644
--- a/simpleperf/cmd_record.cpp
+++ b/simpleperf/cmd_record.cpp
@@ -467,7 +467,7 @@ bool RecordCommand::ParseOptions(const std::vector<std::string>& args,
       if (args[i-1] == "-c") {
         sample_speed_.reset(new SampleSpeed(0, value));
       } else {
-        sample_speed_.reset(new SampleSpeed(AdjustSampleFrequency(value), 0));
+        sample_speed_.reset(new SampleSpeed(value, 0));
       }
       for (auto group_id : wait_setting_speed_event_groups_) {
         event_selection_set_.SetSampleSpeed(group_id, *sample_speed_);
diff --git a/simpleperf/environment.cpp b/simpleperf/environment.cpp
index c244b468..49d3514c 100644
--- a/simpleperf/environment.cpp
+++ b/simpleperf/environment.cpp
@@ -432,24 +432,6 @@ bool GetMaxSampleFrequency(uint64_t* max_sample_freq) {
   return true;
 }
 
-uint64_t AdjustSampleFrequency(uint64_t sample_freq) {
-  if (sample_freq == 0) {
-    LOG(WARNING) << "Sample frequency can't be zero, adjust it to 1";
-    return 1u;
-  }
-  uint64_t max_sample_freq;
-  if (!GetMaxSampleFrequency(&max_sample_freq)) {
-    // Omit the check if can't read perf_event_max_sample_rate.
-    return sample_freq;
-  }
-  if (sample_freq > max_sample_freq) {
-    LOG(WARNING) << "Sample frequency " << sample_freq << " is out of range [1, "
-        << max_sample_freq << "], adjust it to " << max_sample_freq;
-    return max_sample_freq;
-  }
-  return sample_freq;
-}
-
 bool CheckKernelSymbolAddresses() {
   const std::string kptr_restrict_file = "/proc/sys/kernel/kptr_restrict";
   std::string s;
diff --git a/simpleperf/environment.h b/simpleperf/environment.h
index 0f121465..f49e8abb 100644
--- a/simpleperf/environment.h
+++ b/simpleperf/environment.h
@@ -70,7 +70,6 @@ bool GetValidThreadsFromThreadString(const std::string& tid_str, std::set<pid_t>
 
 bool CheckPerfEventLimit();
 bool GetMaxSampleFrequency(uint64_t* max_sample_freq);
-uint64_t AdjustSampleFrequency(uint64_t sample_freq);
 bool CheckKernelSymbolAddresses();
 bool CanRecordRawData();
 
diff --git a/simpleperf/event_selection_set.cpp b/simpleperf/event_selection_set.cpp
index 75cb9063..646de404 100644
--- a/simpleperf/event_selection_set.cpp
+++ b/simpleperf/event_selection_set.cpp
@@ -16,6 +16,7 @@
 
 #include "event_selection_set.h"
 
+#include <algorithm>
 #include <atomic>
 #include <thread>
 
@@ -147,8 +148,12 @@ bool EventSelectionSet::BuildAndCheckEventSelection(
       selection->event_attr.sample_period = DEFAULT_SAMPLE_PERIOD_FOR_TRACEPOINT_EVENT;
     } else {
       selection->event_attr.freq = 1;
-      selection->event_attr.sample_freq =
-          AdjustSampleFrequency(DEFAULT_SAMPLE_FREQ_FOR_NONTRACEPOINT_EVENT);
+      uint64_t freq = DEFAULT_SAMPLE_FREQ_FOR_NONTRACEPOINT_EVENT;
+      uint64_t max_freq;
+      if (GetMaxSampleFrequency(&max_freq)) {
+        freq = std::min(freq, max_freq);
+      }
+      selection->event_attr.sample_freq = freq;
     }
   }
   if (!IsEventAttrSupported(selection->event_attr)) {