8085865: hs_err improvement: Printing /proc/cpuinfo makes too long hs_err files

Summarize information from linux-x86; it's too long and redundant

Reviewed-by: gtriantafill, dholmes, mgerdin, dcubed

hotspot/src/os/aix/vm/os_aix.cpp

@@ -1653,7 +1653,7 @@ void os::print_memory_info(outputStream* st) {
   }
 }
 
-void os::pd_print_cpu_info(outputStream* st) {
+void os::pd_print_cpu_info(outputStream* st, char* buf, size_t buflen) {
   // cpu
   st->print("CPU:");
   st->print("total %d", os::processor_count());

hotspot/src/os/bsd/vm/os_bsd.cpp

@@ -1706,7 +1706,7 @@ void os::print_os_info(outputStream* st) {
   os::Posix::print_load_average(st);
 }
 
-void os::pd_print_cpu_info(outputStream* st) {
+void os::pd_print_cpu_info(outputStream* st, char* buf, size_t buflen) {
   // Nothing to do for now.
 }
 

hotspot/src/os/linux/vm/os_linux.cpp

@@ -2215,12 +2215,52 @@ void os::print_memory_info(outputStream* st) {
   st->cr();
 }
 
-void os::pd_print_cpu_info(outputStream* st) {
-  st->print("\n/proc/cpuinfo:\n");
-  if (!_print_ascii_file("/proc/cpuinfo", st)) {
-    st->print("  <Not Available>");
+// Print the first "model name" line and the first "flags" line
+// that we find and nothing more. We assume "model name" comes
+// before "flags" so if we find a second "model name", then the
+// "flags" field is considered missing.
+static bool print_model_name_and_flags(outputStream* st, char* buf, size_t buflen) {
+#if defined(IA32) || defined(AMD64)
+  // Other platforms have less repetitive cpuinfo files
+  FILE *fp = fopen("/proc/cpuinfo", "r");
+  if (fp) {
+    while (!feof(fp)) {
+      if (fgets(buf, buflen, fp)) {
+        // Assume model name comes before flags
+        bool model_name_printed = false;
+        if (strstr(buf, "model name") != NULL) {
+          if (!model_name_printed) {
+            st->print_raw("\nCPU Model and flags from /proc/cpuinfo:\n");
+            st->print_raw(buf);
+            model_name_printed = true;
+          } else {
+            // model name printed but not flags?  Odd, just return
+            fclose(fp);
+            return true;
+          }
+        }
+        // print the flags line too
+        if (strstr(buf, "flags") != NULL) {
+          st->print_raw(buf);
+          fclose(fp);
+          return true;
+        }
+      }
+    }
+    fclose(fp);
+  }
+#endif // x86 platforms
+  return false;
+}
+
+void os::pd_print_cpu_info(outputStream* st, char* buf, size_t buflen) {
+  // Only print the model name if the platform provides this as a summary
+  if (!print_model_name_and_flags(st, buf, buflen)) {
+    st->print("\n/proc/cpuinfo:\n");
+    if (!_print_ascii_file("/proc/cpuinfo", st)) {
+      st->print_cr("  <Not Available>");
+    }
   }
-  st->cr();
 }
 
 void os::print_siginfo(outputStream* st, void* siginfo) {

hotspot/src/os/solaris/vm/os_solaris.cpp

@@ -1996,7 +1996,7 @@ static bool check_addr0(outputStream* st) {
   return status;
 }
 
-void os::pd_print_cpu_info(outputStream* st) {
+void os::pd_print_cpu_info(outputStream* st, char* buf, size_t buflen) {
   // Nothing to do for now.
 }
 

hotspot/src/os/windows/vm/os_windows.cpp

@@ -1732,7 +1732,7 @@ void os::win32::print_windows_version(outputStream* st) {
   st->cr();
 }
 
-void os::pd_print_cpu_info(outputStream* st) {
+void os::pd_print_cpu_info(outputStream* st, char* buf, size_t buflen) {
   // Nothing to do for now.
 }
 

hotspot/src/share/vm/runtime/os.cpp

@@ -832,7 +832,7 @@ void os::print_environment_variables(outputStream* st, const char** env_list) {
   }
 }
 
-void os::print_cpu_info(outputStream* st) {
+void os::print_cpu_info(outputStream* st, char* buf, size_t buflen) {
   // cpu
   st->print("CPU:");
   st->print("total %d", os::processor_count());
@@ -840,7 +840,7 @@ void os::print_cpu_info(outputStream* st) {
   // st->print("(active %d)", os::active_processor_count());
   st->print(" %s", VM_Version::cpu_features());
   st->cr();
-  pd_print_cpu_info(st);
+  pd_print_cpu_info(st, buf, buflen);
 }
 
 void os::print_date_and_time(outputStream *st, char* buf, size_t buflen) {

hotspot/src/share/vm/runtime/os.hpp

@@ -587,8 +587,8 @@ class os: AllStatic {
   // Output format may be different on different platforms.
   static void print_os_info(outputStream* st);
   static void print_os_info_brief(outputStream* st);
-  static void print_cpu_info(outputStream* st);
-  static void pd_print_cpu_info(outputStream* st);
+  static void print_cpu_info(outputStream* st, char* buf, size_t buflen);
+  static void pd_print_cpu_info(outputStream* st, char* buf, size_t buflen);
   static void print_memory_info(outputStream* st);
   static void print_dll_info(outputStream* st);
   static void print_environment_variables(outputStream* st, const char** env_list);

hotspot/src/share/vm/runtime/vm_version.cpp

@@ -280,7 +280,8 @@ void VM_Version_init() {
 
 #ifndef PRODUCT
   if (PrintMiscellaneous && Verbose) {
-    os::print_cpu_info(tty);
+    char buf[512];
+    os::print_cpu_info(tty, buf, sizeof(buf));
   }
 #endif
 }

hotspot/src/share/vm/utilities/vmError.cpp

@@ -816,7 +816,7 @@ void VMError::report(outputStream* st) {
 
   STEP(250, "(printing CPU info)" )
      if (_verbose) {
-       os::print_cpu_info(st);
+       os::print_cpu_info(st, buf, sizeof(buf));
        st->cr();
      }