src/os/linux/vm/os_linux.cpp

rev 3419 : 7179517: Enable NUMA by default on NUMA hardware
Summary: Enable UseNUMA by default on NUMA hardware
Reviewed-by: jwilhelm

*** 4232,4249 ****
--- 4232,4263 ----
       tty->print_cr("[HotSpot is running with %s, %s(%s)]\n",
            Linux::glibc_version(), Linux::libpthread_version(),
            Linux::is_floating_stack() ? "floating stack" : "fixed stack");
    }
  
+ #ifdef _LP64
+   // For 64 bit numa systems, enable numa features if heap is large enough
+   if (UseNUMA || (FLAG_IS_DEFAULT(UseNUMA) && is_server_class_machine())) {
+ #else
    if (UseNUMA) {
+ #endif
      if (!Linux::libnuma_init()) {
        UseNUMA = false;
      } else {
        if ((Linux::numa_max_node() < 1)) {
          // There's only one node(they start from 0), disable NUMA.
          UseNUMA = false;
        }
+ #ifdef _LP64
+       else {
+         // There is more than 1 node
+         if (FLAG_IS_DEFAULT(UseNUMA) && (MaxHeapSize >= NUMAAutoStartHeapSize)) {
+           UseNUMA = true;
+           UseNUMAInterleaving = true;
+         }
+       }
+ #endif
      }
      // With SHM large pages we cannot uncommit a page, so there's not way
      // we can make the adaptive lgrp chunk resizing work. If the user specified
      // both UseNUMA and UseLargePages (or UseSHM) on the command line - warn and
      // disable adaptive resizing.