src/hotspot/share/runtime/vm_version.cpp

rev 52689 : 8213224: Move code related to GC threads calculation out of AdaptiveSizePolicy
Summary: Consolidate code related to GC threads calculation into a single class

*** 79,90 ****
  int Abstract_VM_Version::_vm_major_version = VERSION_FEATURE;
  int Abstract_VM_Version::_vm_minor_version = VERSION_INTERIM;
  int Abstract_VM_Version::_vm_security_version = VERSION_UPDATE;
  int Abstract_VM_Version::_vm_patch_version = VERSION_PATCH;
  int Abstract_VM_Version::_vm_build_number = VERSION_BUILD;
- unsigned int Abstract_VM_Version::_parallel_worker_threads = 0;
- bool Abstract_VM_Version::_parallel_worker_threads_initialized = false;
  
  #if defined(_LP64)
    #define VMLP "64-Bit "
  #else
    #define VMLP ""
--- 79,88 ----
*** 310,366 ****
      ResourceMark rm;
      LogStream ls(Log(os, cpu)::info());
      os::print_cpu_info(&ls, buf, sizeof(buf));
    }
  }
- 
- unsigned int Abstract_VM_Version::nof_parallel_worker_threads(
-                                                       unsigned int num,
-                                                       unsigned int den,
-                                                       unsigned int switch_pt) {
-   if (FLAG_IS_DEFAULT(ParallelGCThreads)) {
-     assert(ParallelGCThreads == 0, "Default ParallelGCThreads is not 0");
-     unsigned int threads;
-     // For very large machines, there are diminishing returns
-     // for large numbers of worker threads.  Instead of
-     // hogging the whole system, use a fraction of the workers for every
-     // processor after the first 8.  For example, on a 72 cpu machine
-     // and a chosen fraction of 5/8
-     // use 8 + (72 - 8) * (5/8) == 48 worker threads.
-     unsigned int ncpus = (unsigned int) os::initial_active_processor_count();
-     threads = (ncpus <= switch_pt) ?
-              ncpus :
-              (switch_pt + ((ncpus - switch_pt) * num) / den);
- #ifndef _LP64
-     // On 32-bit binaries the virtual address space available to the JVM
-     // is usually limited to 2-3 GB (depends on the platform).
-     // Do not use up address space with too many threads (stacks and per-thread
-     // data). Note that x86 apps running on Win64 have 2 stacks per thread.
-     // GC may more generally scale down threads by max heap size (etc), but the
-     // consequences of over-provisioning threads are higher on 32-bit JVMS,
-     // so add hard limit here:
-     threads = MIN2(threads, (2*switch_pt));
- #endif
-     return threads;
-   } else {
-     return ParallelGCThreads;
-   }
- }
- 
- unsigned int Abstract_VM_Version::calc_parallel_worker_threads() {
-   return nof_parallel_worker_threads(5, 8, 8);
- }
- 
- 
- // Does not set the _initialized flag since it is
- // a global flag.
- unsigned int Abstract_VM_Version::parallel_worker_threads() {
-   if (!_parallel_worker_threads_initialized) {
-     if (FLAG_IS_DEFAULT(ParallelGCThreads)) {
-       _parallel_worker_threads = VM_Version::calc_parallel_worker_threads();
-     } else {
-       _parallel_worker_threads = ParallelGCThreads;
-     }
-     _parallel_worker_threads_initialized = true;
-   }
-   return _parallel_worker_threads;
- }
--- 308,312 ----