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8064457: Introduce compressed oops mode disjoint base and improve compressed heap handling

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Introduce compressed oops mode disjoint base and improve compressed heap handling.

Reviewed-by: kvn, coleenp
This commit is contained in:
Goetz Lindenmaier 2015-01-05 12:07:37 -05:00
parent 5b8ee4c102
commit 1c18aef92c
13 changed files with 530 additions and 296 deletions
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197
hotspot/src/share/vm/memory/universe.cpp
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@ -1,5 +1,5 @@
/*
* Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 1997, 2015, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
@ -694,103 +694,6 @@ jint universe_init() {
// NarrowOopHeapBaseMin + heap_size < 32Gb
// HeapBased - Use compressed oops with heap base + encoding.
// 4Gb
static const uint64_t UnscaledOopHeapMax = (uint64_t(max_juint) + 1);
// 32Gb
// OopEncodingHeapMax == UnscaledOopHeapMax << LogMinObjAlignmentInBytes;
char* Universe::preferred_heap_base(size_t heap_size, size_t alignment, NARROW_OOP_MODE mode) {
assert(is_size_aligned((size_t)OopEncodingHeapMax, alignment), "Must be");
assert(is_size_aligned((size_t)UnscaledOopHeapMax, alignment), "Must be");
assert(is_size_aligned(heap_size, alignment), "Must be");
uintx heap_base_min_address_aligned = align_size_up(HeapBaseMinAddress, alignment);
size_t base = 0;
#ifdef _LP64
if (UseCompressedOops) {
assert(mode == UnscaledNarrowOop ||
mode == ZeroBasedNarrowOop ||
mode == HeapBasedNarrowOop, "mode is invalid");
const size_t total_size = heap_size + heap_base_min_address_aligned;
// Return specified base for the first request.
if (!FLAG_IS_DEFAULT(HeapBaseMinAddress) && (mode == UnscaledNarrowOop)) {
base = heap_base_min_address_aligned;
// If the total size is small enough to allow UnscaledNarrowOop then
// just use UnscaledNarrowOop.
} else if ((total_size <= OopEncodingHeapMax) && (mode != HeapBasedNarrowOop)) {
if ((total_size <= UnscaledOopHeapMax) && (mode == UnscaledNarrowOop) &&
(Universe::narrow_oop_shift() == 0)) {
// Use 32-bits oops without encoding and
// place heap's top on the 4Gb boundary
base = (UnscaledOopHeapMax - heap_size);
} else {
// Can't reserve with NarrowOopShift == 0
Universe::set_narrow_oop_shift(LogMinObjAlignmentInBytes);
if (mode == UnscaledNarrowOop ||
mode == ZeroBasedNarrowOop && total_size <= UnscaledOopHeapMax) {
// Use zero based compressed oops with encoding and
// place heap's top on the 32Gb boundary in case
// total_size > 4Gb or failed to reserve below 4Gb.
uint64_t heap_top = OopEncodingHeapMax;
// For small heaps, save some space for compressed class pointer
// space so it can be decoded with no base.
if (UseCompressedClassPointers && !UseSharedSpaces &&
OopEncodingHeapMax <= 32*G) {
uint64_t class_space = align_size_up(CompressedClassSpaceSize, alignment);
assert(is_size_aligned((size_t)OopEncodingHeapMax-class_space,
alignment), "difference must be aligned too");
uint64_t new_top = OopEncodingHeapMax-class_space;
if (total_size <= new_top) {
heap_top = new_top;
}
}
// Align base to the adjusted top of the heap
base = heap_top - heap_size;
}
}
} else {
// UnscaledNarrowOop encoding didn't work, and no base was found for ZeroBasedOops or
// HeapBasedNarrowOop encoding was requested. So, can't reserve below 32Gb.
Universe::set_narrow_oop_shift(LogMinObjAlignmentInBytes);
}
// Set narrow_oop_base and narrow_oop_use_implicit_null_checks
// used in ReservedHeapSpace() constructors.
// The final values will be set in initialize_heap() below.
if ((base != 0) && ((base + heap_size) <= OopEncodingHeapMax)) {
// Use zero based compressed oops
Universe::set_narrow_oop_base(NULL);
// Don't need guard page for implicit checks in indexed
// addressing mode with zero based Compressed Oops.
Universe::set_narrow_oop_use_implicit_null_checks(true);
} else {
// Set to a non-NULL value so the ReservedSpace ctor computes
// the correct no-access prefix.
// The final value will be set in initialize_heap() below.
Universe::set_narrow_oop_base((address)UnscaledOopHeapMax);
#if defined(_WIN64) || defined(AIX)
if (UseLargePages) {
// Cannot allocate guard pages for implicit checks in indexed
// addressing mode when large pages are specified on windows.
Universe::set_narrow_oop_use_implicit_null_checks(false);
}
#endif // _WIN64
}
}
#endif
assert(is_ptr_aligned((char*)base, alignment), "Must be");
return (char*)base; // also return NULL (don't care) for 32-bit VM
}
jint Universe::initialize_heap() {
if (UseParallelGC) {
@ -844,30 +747,13 @@ jint Universe::initialize_heap() {
// See needs_explicit_null_check.
// Only set the heap base for compressed oops because it indicates
// compressed oops for pstack code.
if (((uint64_t)Universe::heap()->reserved_region().end() > OopEncodingHeapMax)) {
// Can't reserve heap below 32Gb.
// keep the Universe::narrow_oop_base() set in Universe::reserve_heap()
if ((uint64_t)Universe::heap()->reserved_region().end() > UnscaledOopHeapMax) {
// Didn't reserve heap below 4Gb. Must shift.
Universe::set_narrow_oop_shift(LogMinObjAlignmentInBytes);
#ifdef AIX
// There is no protected page before the heap. This assures all oops
// are decoded so that NULL is preserved, so this page will not be accessed.
Universe::set_narrow_oop_use_implicit_null_checks(false);
#endif
} else {
}
if ((uint64_t)Universe::heap()->reserved_region().end() <= OopEncodingHeapMax) {
// Did reserve heap below 32Gb. Can use base == 0;
Universe::set_narrow_oop_base(0);
#ifdef _WIN64
if (!Universe::narrow_oop_use_implicit_null_checks()) {
// Don't need guard page for implicit checks in indexed addressing
// mode with zero based Compressed Oops.
Universe::set_narrow_oop_use_implicit_null_checks(true);
}
#endif // _WIN64
if((uint64_t)Universe::heap()->reserved_region().end() > UnscaledOopHeapMax) {
// Can't reserve heap below 4Gb.
Universe::set_narrow_oop_shift(LogMinObjAlignmentInBytes);
} else {
Universe::set_narrow_oop_shift(0);
}
}
Universe::set_narrow_ptrs_base(Universe::narrow_oop_base());
@ -875,6 +761,11 @@ jint Universe::initialize_heap() {
if (PrintCompressedOopsMode || (PrintMiscellaneous && Verbose)) {
Universe::print_compressed_oops_mode();
}
// Tell tests in which mode we run.
Arguments::PropertyList_add(new SystemProperty("java.vm.compressedOopsMode",
narrow_oop_mode_to_string(narrow_oop_mode()),
false));
}
// Universe::narrow_oop_base() is one page below the heap.
assert((intptr_t)Universe::narrow_oop_base() <= (intptr_t)(Universe::heap()->base() -
@ -903,22 +794,27 @@ void Universe::print_compressed_oops_mode() {
tty->print(", Compressed Oops mode: %s", narrow_oop_mode_to_string(narrow_oop_mode()));
if (Universe::narrow_oop_base() != 0) {
tty->print(":" PTR_FORMAT, Universe::narrow_oop_base());
tty->print(": " PTR_FORMAT, Universe::narrow_oop_base());
}
if (Universe::narrow_oop_shift() != 0) {
tty->print(", Oop shift amount: %d", Universe::narrow_oop_shift());
}
if (!Universe::narrow_oop_use_implicit_null_checks()) {
tty->print(", no protected page in front of the heap");
}
tty->cr();
tty->cr();
}
// Reserve the Java heap, which is now the same for all GCs.
ReservedSpace Universe::reserve_heap(size_t heap_size, size_t alignment) {
assert(alignment <= Arguments::conservative_max_heap_alignment(),
err_msg("actual alignment "SIZE_FORMAT" must be within maximum heap alignment "SIZE_FORMAT,
alignment, Arguments::conservative_max_heap_alignment()));
size_t total_reserved = align_size_up(heap_size, alignment);
assert(!UseCompressedOops || (total_reserved <= (OopEncodingHeapMax - os::vm_page_size())),
"heap size is too big for compressed oops");
@ -928,46 +824,31 @@ ReservedSpace Universe::reserve_heap(size_t heap_size, size_t alignment) {
|| UseParallelGC
|| use_large_pages, "Wrong alignment to use large pages");
char* addr = Universe::preferred_heap_base(total_reserved, alignment, Universe::UnscaledNarrowOop);
// Now create the space.
ReservedHeapSpace total_rs(total_reserved, alignment, use_large_pages);
ReservedHeapSpace total_rs(total_reserved, alignment, use_large_pages, addr);
if (total_rs.is_reserved()) {
assert((total_reserved == total_rs.size()) && ((uintptr_t)total_rs.base() % alignment == 0),
"must be exactly of required size and alignment");
// We are good.
if (UseCompressedOops) {
if (addr != NULL && !total_rs.is_reserved()) {
// Failed to reserve at specified address - the requested memory
// region is taken already, for example, by 'java' launcher.
// Try again to reserver heap higher.
addr = Universe::preferred_heap_base(total_reserved, alignment, Universe::ZeroBasedNarrowOop);
ReservedHeapSpace total_rs0(total_reserved, alignment,
use_large_pages, addr);
if (addr != NULL && !total_rs0.is_reserved()) {
// Failed to reserve at specified address again - give up.
addr = Universe::preferred_heap_base(total_reserved, alignment, Universe::HeapBasedNarrowOop);
assert(addr == NULL, "");
ReservedHeapSpace total_rs1(total_reserved, alignment,
use_large_pages, addr);
total_rs = total_rs1;
} else {
total_rs = total_rs0;
}
if (UseCompressedOops) {
// Universe::initialize_heap() will reset this to NULL if unscaled
// or zero-based narrow oops are actually used.
// Else heap start and base MUST differ, so that NULL can be encoded nonambigous.
Universe::set_narrow_oop_base((address)total_rs.compressed_oop_base());
}
}
if (!total_rs.is_reserved()) {
vm_exit_during_initialization(err_msg("Could not reserve enough space for " SIZE_FORMAT "KB object heap", total_reserved/K));
return total_rs;
}
if (UseCompressedOops) {
// Universe::initialize_heap() will reset this to NULL if unscaled
// or zero-based narrow oops are actually used.
address base = (address)(total_rs.base() - os::vm_page_size());
Universe::set_narrow_oop_base(base);
}
return total_rs;
vm_exit_during_initialization(
err_msg("Could not reserve enough space for " SIZE_FORMAT "KB object heap",
total_reserved/K));
// satisfy compiler
ShouldNotReachHere();
return ReservedHeapSpace(0, 0, false);
}
@ -985,6 +866,8 @@ const char* Universe::narrow_oop_mode_to_string(Universe::NARROW_OOP_MODE mode)
return "32-bit";
case ZeroBasedNarrowOop:
return "Zero based";
case DisjointBaseNarrowOop:
return "Non-zero disjoint base";
case HeapBasedNarrowOop:
return "Non-zero based";
}
@ -995,6 +878,10 @@ const char* Universe::narrow_oop_mode_to_string(Universe::NARROW_OOP_MODE mode)
Universe::NARROW_OOP_MODE Universe::narrow_oop_mode() {
if (narrow_oop_base_disjoint()) {
return DisjointBaseNarrowOop;
}
if (narrow_oop_base() != 0) {
return HeapBasedNarrowOop;
}