821 #else
822
823 if (bytes < 2 * G) {
824 return true;
825 }
826
827 char* addr = reserve_memory(bytes, NULL);
828
829 if (addr != NULL) {
830 release_memory(addr, bytes);
831 }
832
833 return addr != NULL;
834 #endif // AMD64
835 }
836
837 ////////////////////////////////////////////////////////////////////////////////
838 // thread stack
839
840 #ifdef AMD64
841 size_t os::Bsd::min_stack_allowed = 64 * K;
842 #else
843 size_t os::Bsd::min_stack_allowed = (48 DEBUG_ONLY(+4))*K;
844
845 #ifdef __GNUC__
846 #define GET_GS() ({int gs; __asm__ volatile("movw %%gs, %w0":"=q"(gs)); gs&0xffff;})
847 #endif
848
849 #endif // AMD64
850
851 // return default stack size for thr_type
852 size_t os::Bsd::default_stack_size(os::ThreadType thr_type) {
853 // default stack size (compiler thread needs larger stack)
854 #ifdef AMD64
855 size_t s = (thr_type == os::compiler_thread ? 4 * M : 1 * M);
856 #else
857 size_t s = (thr_type == os::compiler_thread ? 2 * M : 512 * K);
858 #endif // AMD64
859 return s;
860 }
861
862 size_t os::Bsd::default_guard_size(os::ThreadType thr_type) {
863 // Creating guard page is very expensive. Java thread has HotSpot
864 // guard page, only enable glibc guard page for non-Java threads.
865 return (thr_type == java_thread ? 0 : page_size());
866 }
867
868 // Java thread:
869 //
870 // Low memory addresses
871 // +------------------------+
872 // | |\ JavaThread created by VM does not have glibc
873 // | glibc guard page | - guard, attached Java thread usually has
874 // | |/ 1 page glibc guard.
875 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size()
876 // | |\
877 // | HotSpot Guard Pages | - red and yellow pages
878 // | |/
879 // +------------------------+ JavaThread::stack_yellow_zone_base()
880 // | |\
881 // | Normal Stack | -
882 // | |/
883 // P2 +------------------------+ Thread::stack_base()
884 //
885 // Non-Java thread:
886 //
|
821 #else
822
823 if (bytes < 2 * G) {
824 return true;
825 }
826
827 char* addr = reserve_memory(bytes, NULL);
828
829 if (addr != NULL) {
830 release_memory(addr, bytes);
831 }
832
833 return addr != NULL;
834 #endif // AMD64
835 }
836
837 ////////////////////////////////////////////////////////////////////////////////
838 // thread stack
839
840 #ifdef AMD64
841 size_t os::Posix::_compiler_thread_min_stack_allowed = 64 * K;
842 size_t os::Posix::_java_thread_min_stack_allowed = 64 * K;
843 size_t os::Posix::_vm_internal_thread_min_stack_allowed = 64 * K;
844 #else
845 size_t os::Posix::_compiler_thread_min_stack_allowed = (48 DEBUG_ONLY(+ 4)) * K;
846 size_t os::Posix::_java_thread_min_stack_allowed = (48 DEBUG_ONLY(+ 4)) * K;
847 size_t os::Posix::_vm_internal_thread_min_stack_allowed = (48 DEBUG_ONLY(+ 4)) * K;
848
849 #ifdef __GNUC__
850 #define GET_GS() ({int gs; __asm__ volatile("movw %%gs, %w0":"=q"(gs)); gs&0xffff;})
851 #endif
852
853 #endif // AMD64
854
855 // return default stack size for thr_type
856 size_t os::Posix::default_stack_size(os::ThreadType thr_type) {
857 // default stack size (compiler thread needs larger stack)
858 #ifdef AMD64
859 size_t s = (thr_type == os::compiler_thread ? 4 * M : 1 * M);
860 #else
861 size_t s = (thr_type == os::compiler_thread ? 2 * M : 512 * K);
862 #endif // AMD64
863 return s;
864 }
865
866
867 // Java thread:
868 //
869 // Low memory addresses
870 // +------------------------+
871 // | |\ JavaThread created by VM does not have glibc
872 // | glibc guard page | - guard, attached Java thread usually has
873 // | |/ 1 page glibc guard.
874 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size()
875 // | |\
876 // | HotSpot Guard Pages | - red and yellow pages
877 // | |/
878 // +------------------------+ JavaThread::stack_yellow_zone_base()
879 // | |\
880 // | Normal Stack | -
881 // | |/
882 // P2 +------------------------+ Thread::stack_base()
883 //
884 // Non-Java thread:
885 //
|