src/os/linux/vm/os_linux.cpp

*** 4769,4778 ****
--- 4769,4797 ----
    if (!linux_mprotect((char *)_polling_page, Linux::page_size(), PROT_READ)) {
      fatal("Could not enable polling page");
    }
  }
  
+ // older glibc versions don't have this macro (which expands to
+ // an optimized bit-counting function) so we have to roll our own
+ #ifndef CPU_COUNT
+ 
+ static int _cpu_count(const cpu_set_t* cpus) {
+   int count = 0;
+   // only look up to the number of configured processors
+   for (int i = 0; i < os::processor_count(); i++) {
+     if (CPU_ISSET(i, cpus)) {
+       count++;
+     }
+   } 
+   return count;
+ }
+ 
+ #define CPU_COUNT(cpus) _cpu_count(cpus)
+ 
+ #endif // CPU_COUNT
+ 
  // Get the current number of available processors for this process.
  // This value can change at any time during a process's lifetime.
  // sched_getaffinity gives an accurate answer as it accounts for cpusets.
  // If it appears there may be more than 1024 processors then we do a
  // dynamic check - see 6515172 for details.
*** 4784,4793 ****
--- 4803,4815 ----
    int cpus_size = sizeof(cpu_set_t);
  
    int configured_cpus = processor_count();  // upper bound on available cpus
    int cpu_count = 0;
  
+ // old build platforms may not support dynamic cpu sets
+ #ifdef CPU_ALLOC
+ 
    // To enable easy testing of the dynamic path on different platforms we
    // introduce a diagnostic flag: UseCpuAllocPath
    if (configured_cpus >= CPU_SETSIZE || UseCpuAllocPath) {
      // kernel may use a mask bigger than cpu_set_t
      log_trace(os)("active_processor_count: using dynamic path %s"
*** 4812,4821 ****
--- 4834,4851 ----
    }
    else {
      log_trace(os)("active_processor_count: using static path - configured processors: %d",
                    configured_cpus);
    }
+ #else // CPU_ALLOC
+ 
+ #define CPU_COUNT_S(size, cpus) -1
+ #define CPU_FREE(cpus) 
+ 
+   log_trace(os)("active_processor_count: only static path available - configured processors: %d",
+                 configured_cpus);  
+ #endif // CPU_ALLOC
  
    // pid 0 means the current thread - which we have to assume represents the process
    if (sched_getaffinity(0, cpus_size, cpus_p) == 0) {
      if (cpus_p != &cpus) {
        cpu_count = CPU_COUNT_S(cpus_size, cpus_p);