5089   // call to exit(3C). There can be only 32 of these functions registered
5090   // and atexit() does not set errno.
5091 
5092   if (PerfAllowAtExitRegistration) {
5093     // only register atexit functions if PerfAllowAtExitRegistration is set.
5094     // atexit functions can be delayed until process exit time, which
5095     // can be problematic for embedded VM situations. Embedded VMs should
5096     // call DestroyJavaVM() to assure that VM resources are released.
5097 
5098     // note: perfMemory_exit_helper atexit function may be removed in
5099     // the future if the appropriate cleanup code can be added to the
5100     // VM_Exit VMOperation's doit method.
5101     if (atexit(perfMemory_exit_helper) != 0) {
5102       warning("os::init_2 atexit(perfMemory_exit_helper) failed");
5103     }
5104   }
5105 
5106   // initialize thread priority policy
5107   prio_init();
5108 
5109   if (!FLAG_IS_DEFAULT(AllocateHeapAt)) {
5110     set_coredump_filter(false /*largepages*/, true /*dax_shared*/);
5111   }
5112   return JNI_OK;
5113 }
5114 
5115 // Mark the polling page as unreadable
5116 void os::make_polling_page_unreadable(void) {
5117   if (!guard_memory((char*)_polling_page, Linux::page_size())) {
5118     fatal("Could not disable polling page");
5119   }
5120 }
5121 
5122 // Mark the polling page as readable
5123 void os::make_polling_page_readable(void) {
5124   if (!linux_mprotect((char *)_polling_page, Linux::page_size(), PROT_READ)) {
5125     fatal("Could not enable polling page");
5126   }
5127 }
5128 
5129 // older glibc versions don't have this macro (which expands to

5089   // call to exit(3C). There can be only 32 of these functions registered
5090   // and atexit() does not set errno.
5091 
5092   if (PerfAllowAtExitRegistration) {
5093     // only register atexit functions if PerfAllowAtExitRegistration is set.
5094     // atexit functions can be delayed until process exit time, which
5095     // can be problematic for embedded VM situations. Embedded VMs should
5096     // call DestroyJavaVM() to assure that VM resources are released.
5097 
5098     // note: perfMemory_exit_helper atexit function may be removed in
5099     // the future if the appropriate cleanup code can be added to the
5100     // VM_Exit VMOperation's doit method.
5101     if (atexit(perfMemory_exit_helper) != 0) {
5102       warning("os::init_2 atexit(perfMemory_exit_helper) failed");
5103     }
5104   }
5105 
5106   // initialize thread priority policy
5107   prio_init();
5108 
5109   if (!FLAG_IS_DEFAULT(AllocateHeapAt) || !FLAG_IS_DEFAULT(AllocateOldGenAt)) {
5110     set_coredump_filter(false /*largepages*/, true /*dax_shared*/);
5111   }
5112   return JNI_OK;
5113 }
5114 
5115 // Mark the polling page as unreadable
5116 void os::make_polling_page_unreadable(void) {
5117   if (!guard_memory((char*)_polling_page, Linux::page_size())) {
5118     fatal("Could not disable polling page");
5119   }
5120 }
5121 
5122 // Mark the polling page as readable
5123 void os::make_polling_page_readable(void) {
5124   if (!linux_mprotect((char *)_polling_page, Linux::page_size(), PROT_READ)) {
5125     fatal("Could not enable polling page");
5126   }
5127 }
5128 
5129 // older glibc versions don't have this macro (which expands to