ruby: eliminate non-determinism from ruby.stats output

Get rid of non-deterministic "stats" in ruby.stats output
such as time & date of run, elapsed & CPU time used,
and memory usage.  These values cause spurious
miscomparisons when looking at output diffs (though
they don't affect regressions, since the regressions
pass/fail status currently ignores ruby.stats entirely).

Most of this information is already captured in other
places (time & date in stdout, elapsed time & mem usage
in stats.txt), where the regression script is smart
enough to filter it out.  It seems easier to get rid of
the redundant output rather than teaching the
regression tester to ignore the same information in
two different places.

src/mem/ruby/profiler/Profiler.cc

@@ -42,9 +42,6 @@
    ----------------------------------------------------------------------
 */
 
-// Allows use of times() library call, which determines virtual runtime
-#include <sys/resource.h>
-#include <sys/times.h>
 #include <sys/types.h>
 #include <unistd.h>
 
@@ -64,9 +61,6 @@
 using namespace std;
 using m5::stl_helpers::operator<<;
 
-static double process_memory_total();
-static double process_memory_resident();
-
 Profiler::Profiler(const Params *p)
     : SimObject(p)
 {
@@ -385,49 +379,13 @@ Profiler::printStats(ostream& out, bool short_stats)
     out << "Profiler Stats" << endl;
     out << "--------------" << endl;
 
-    time_t real_time_current = time(NULL);
-    double seconds = difftime(real_time_current, m_real_time_start_time);
-    double minutes = seconds / 60.0;
-    double hours = minutes / 60.0;
-    double days = hours / 24.0;
     Cycles ruby_cycles = g_system_ptr->curCycle()-m_ruby_start;
 
-    if (!short_stats) {
-        out << "Elapsed_time_in_seconds: " << seconds << endl;
-        out << "Elapsed_time_in_minutes: " << minutes << endl;
-        out << "Elapsed_time_in_hours: " << hours << endl;
-        out << "Elapsed_time_in_days: " << days << endl;
-        out << endl;
-    }
-
-    // print the virtual runtimes as well
-    struct tms vtime;
-    times(&vtime);
-    seconds = (vtime.tms_utime + vtime.tms_stime) / 100.0;
-    minutes = seconds / 60.0;
-    hours = minutes / 60.0;
-    days = hours / 24.0;
-    out << "Virtual_time_in_seconds: " << seconds << endl;
-    out << "Virtual_time_in_minutes: " << minutes << endl;
-    out << "Virtual_time_in_hours:   " << hours << endl;
-    out << "Virtual_time_in_days:    " << days << endl;
-    out << endl;
-
     out << "Ruby_current_time: " << g_system_ptr->curCycle() << endl;
     out << "Ruby_start_time: " << m_ruby_start << endl;
     out << "Ruby_cycles: " << ruby_cycles << endl;
     out << endl;
 
-    if (!short_stats) {
-        out << "mbytes_resident: " << process_memory_resident() << endl;
-        out << "mbytes_total: " << process_memory_total() << endl;
-        if (process_memory_total() > 0) {
-            out << "resident_ratio: "
-                << process_memory_resident()/process_memory_total() << endl;
-        }
-        out << endl;
-    }
-
     if (!short_stats) {
         out << "Busy Controller Counts:" << endl;
         for (uint32_t i = 0; i < MachineType_NUM; i++) {
@@ -571,35 +529,6 @@ Profiler::bankBusy()
     m_busyBankCount++;
 }
 
-// Helper function
-static double
-process_memory_total()
-{
-    // 4kB page size, 1024*1024 bytes per MB,
-    const double MULTIPLIER = 4096.0 / (1024.0 * 1024.0);
-    ifstream proc_file;
-    proc_file.open("/proc/self/statm");
-    int total_size_in_pages = 0;
-    int res_size_in_pages = 0;
-    proc_file >> total_size_in_pages;
-    proc_file >> res_size_in_pages;
-    return double(total_size_in_pages) * MULTIPLIER; // size in megabytes
-}
-
-static double
-process_memory_resident()
-{
-    // 4kB page size, 1024*1024 bytes per MB,
-    const double MULTIPLIER = 4096.0 / (1024.0 * 1024.0);
-    ifstream proc_file;
-    proc_file.open("/proc/self/statm");
-    int total_size_in_pages = 0;
-    int res_size_in_pages = 0;
-    proc_file >> total_size_in_pages;
-    proc_file >> res_size_in_pages;
-    return double(res_size_in_pages) * MULTIPLIER; // size in megabytes
-}
-
 void
 Profiler::rubyWatch(int id)
 {

src/mem/ruby/system/System.cc

@@ -136,12 +136,6 @@ RubySystem::~RubySystem()
 void
 RubySystem::printStats(ostream& out)
 {
-    const time_t T = time(NULL);
-    tm *localTime = localtime(&T);
-    char buf[100];
-    strftime(buf, 100, "%b/%d/%Y %H:%M:%S", localTime);
-    out << "Real time: " << buf << endl;
-
     m_profiler_ptr->printStats(out);
 }