8354811: clock_tics_per_sec code duplication between os_linux and os_posix

Reviewed-by: lucy, clanger, asteiner

Author: MBaesken

src/hotspot/os/aix/os_perf_aix.cpp

@@ -118,7 +118,6 @@ static OSReturn get_lcpu_ticks(perfstat_id_t* lcpu_name, cpu_tick_store_t* ptick
  * Return CPU load caused by the currently executing process (the jvm).
  */
 static OSReturn get_jvm_load(double* jvm_uload, double* jvm_sload) {
-  static clock_t ticks_per_sec = sysconf(_SC_CLK_TCK);
   static u_longlong_t last_timebase = 0;
 
   perfstat_process_t jvm_stats;
@@ -204,8 +203,6 @@ static bool populate_lcpu_names(int ncpus, perfstat_id_t* lcpu_names) {
  * (Context Switches / Tick) * (Tick / s) = Context Switches per second
  */
 static OSReturn perf_context_switch_rate(double* rate) {
-  static clock_t ticks_per_sec = sysconf(_SC_CLK_TCK);
-
   u_longlong_t ticks;
   perfstat_cpu_total_t cpu_stats;
 
@@ -214,7 +211,7 @@ static OSReturn perf_context_switch_rate(double* rate) {
    }
 
    ticks = cpu_stats.user + cpu_stats.sys + cpu_stats.idle + cpu_stats.wait;
-   *rate = (cpu_stats.pswitch / ticks) * ticks_per_sec;
+   *rate = (cpu_stats.pswitch / ticks) * os::Posix::clock_tics_per_second();
 
    return OS_OK;
 }

src/hotspot/os/linux/os_linux.cpp

@@ -210,8 +210,6 @@ typedef int (*malloc_info_func_t)(int options, FILE *stream);
 static malloc_info_func_t g_malloc_info = nullptr;
 #endif // __GLIBC__
 
-static int clock_tics_per_sec = 100;
-
 // If the VM might have been created on the primordial thread, we need to resolve the
 // primordial thread stack bounds and check if the current thread might be the
 // primordial thread in places. If we know that the primordial thread is never used,
@@ -4378,8 +4376,6 @@ static void check_pax(void) {
 // this is called _before_ most of the global arguments have been parsed
 void os::init(void) {
   char dummy;   // used to get a guess on initial stack address
-
-  clock_tics_per_sec = checked_cast<int>(sysconf(_SC_CLK_TCK));
   int sys_pg_size = checked_cast<int>(sysconf(_SC_PAGESIZE));
   if (sys_pg_size < 0) {
     fatal("os_linux.cpp: os::init: sysconf failed (%s)",
@@ -5132,9 +5128,9 @@ static jlong slow_thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
                  &user_time, &sys_time);
   if (count != 13) return -1;
   if (user_sys_cpu_time) {
-    return ((jlong)sys_time + (jlong)user_time) * (1000000000 / clock_tics_per_sec);
+    return ((jlong)sys_time + (jlong)user_time) * (1000000000 / os::Posix::clock_tics_per_second());
   } else {
-    return (jlong)user_time * (1000000000 / clock_tics_per_sec);
+    return (jlong)user_time * (1000000000 / os::Posix::clock_tics_per_second());
   }
 }
 

src/hotspot/os/posix/os_posix.cpp

@@ -1326,6 +1326,10 @@ void os::Posix::init_2(void) {
                _use_clock_monotonic_condattr ? "CLOCK_MONOTONIC" : "the default clock");
 }
 
+int os::Posix::clock_tics_per_second() {
+  return clock_tics_per_sec;
+}
+
 // Utility to convert the given timeout to an absolute timespec
 // (based on the appropriate clock) to use with pthread_cond_timewait,
 // and sem_timedwait().

src/hotspot/os/posix/os_posix.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999, 2024, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2025, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -91,6 +91,9 @@ class os::Posix {
 
   static void to_RTC_abstime(timespec* abstime, int64_t millis);
 
+  // clock ticks per second of the system
+  static int clock_tics_per_second();
+
   static bool handle_stack_overflow(JavaThread* thread, address addr, address pc,
                                     const void* ucVoid,
                                     address* stub);