--- a/src/hotspot/cpu/aarch64/gc/z/zGlobals_aarch64.cpp Thu Oct 24 16:37:22 2019 +0200
+++ b/src/hotspot/cpu/aarch64/gc/z/zGlobals_aarch64.cpp Thu Oct 24 17:24:58 2019 +0200
@@ -142,8 +142,7 @@
size_t ZPlatformAddressOffsetBits() {
const size_t min_address_offset_bits = 42; // 4TB
const size_t max_address_offset_bits = 44; // 16TB
- const size_t virtual_to_physical_ratio = 7; // 7:1
- const size_t address_offset = ZUtils::round_up_power_of_2(MaxHeapSize * virtual_to_physical_ratio);
+ const size_t address_offset = ZUtils::round_up_power_of_2(MaxHeapSize * ZVirtualToPhysicalRatio);
const size_t address_offset_bits = log2_intptr(address_offset);
return MIN2(MAX2(address_offset_bits, min_address_offset_bits), max_address_offset_bits);
}
--- a/src/hotspot/cpu/aarch64/gc/z/zGlobals_aarch64.hpp Thu Oct 24 16:37:22 2019 +0200
+++ b/src/hotspot/cpu/aarch64/gc/z/zGlobals_aarch64.hpp Thu Oct 24 17:24:58 2019 +0200
@@ -24,23 +24,13 @@
#ifndef CPU_AARCH64_GC_Z_ZGLOBALS_AARCH64_HPP
#define CPU_AARCH64_GC_Z_ZGLOBALS_AARCH64_HPP
-//
-// Page Allocation Tiers
-// ---------------------
-//
-// Page Type Page Size Object Size Limit Object Alignment
-// ------------------------------------------------------------------
-// Small 2M <= 265K <MinObjAlignmentInBytes>
-// Medium 32M <= 4M 4K
-// Large X*M > 4M 2M
-// ------------------------------------------------------------------
-//
const size_t ZPlatformGranuleSizeShift = 21; // 2MB
+const size_t ZPlatformHeapViews = 3;
const size_t ZPlatformNMethodDisarmedOffset = 4;
const size_t ZPlatformCacheLineSize = 64;
-uintptr_t ZPlatformAddressBase();
-size_t ZPlatformAddressOffsetBits();
-size_t ZPlatformAddressMetadataShift();
+uintptr_t ZPlatformAddressBase();
+size_t ZPlatformAddressOffsetBits();
+size_t ZPlatformAddressMetadataShift();
#endif // CPU_AARCH64_GC_Z_ZGLOBALS_AARCH64_HPP
--- a/src/hotspot/cpu/x86/gc/z/zGlobals_x86.cpp Thu Oct 24 16:37:22 2019 +0200
+++ b/src/hotspot/cpu/x86/gc/z/zGlobals_x86.cpp Thu Oct 24 17:24:58 2019 +0200
@@ -142,8 +142,7 @@
size_t ZPlatformAddressOffsetBits() {
const size_t min_address_offset_bits = 42; // 4TB
const size_t max_address_offset_bits = 44; // 16TB
- const size_t virtual_to_physical_ratio = 7; // 7:1
- const size_t address_offset = ZUtils::round_up_power_of_2(MaxHeapSize * virtual_to_physical_ratio);
+ const size_t address_offset = ZUtils::round_up_power_of_2(MaxHeapSize * ZVirtualToPhysicalRatio);
const size_t address_offset_bits = log2_intptr(address_offset);
return MIN2(MAX2(address_offset_bits, min_address_offset_bits), max_address_offset_bits);
}
--- a/src/hotspot/cpu/x86/gc/z/zGlobals_x86.hpp Thu Oct 24 16:37:22 2019 +0200
+++ b/src/hotspot/cpu/x86/gc/z/zGlobals_x86.hpp Thu Oct 24 17:24:58 2019 +0200
@@ -24,23 +24,13 @@
#ifndef CPU_X86_GC_Z_ZGLOBALS_X86_HPP
#define CPU_X86_GC_Z_ZGLOBALS_X86_HPP
-//
-// Page Allocation Tiers
-// ---------------------
-//
-// Page Type Page Size Object Size Limit Object Alignment
-// ------------------------------------------------------------------
-// Small 2M <= 265K <MinObjAlignmentInBytes>
-// Medium 32M <= 4M 4K
-// Large X*M > 4M 2M
-// ------------------------------------------------------------------
-//
const size_t ZPlatformGranuleSizeShift = 21; // 2MB
+const size_t ZPlatformHeapViews = 3;
const size_t ZPlatformNMethodDisarmedOffset = 4;
const size_t ZPlatformCacheLineSize = 64;
-uintptr_t ZPlatformAddressBase();
-size_t ZPlatformAddressOffsetBits();
-size_t ZPlatformAddressMetadataShift();
+uintptr_t ZPlatformAddressBase();
+size_t ZPlatformAddressOffsetBits();
+size_t ZPlatformAddressMetadataShift();
#endif // CPU_X86_GC_Z_ZGLOBALS_X86_HPP
--- a/src/hotspot/os/posix/gc/z/zVirtualMemory_posix.cpp Thu Oct 24 16:37:22 2019 +0200
+++ b/src/hotspot/os/posix/gc/z/zVirtualMemory_posix.cpp Thu Oct 24 17:24:58 2019 +0200
@@ -51,7 +51,7 @@
return true;
}
-bool ZVirtualMemoryManager::reserve_platform(uintptr_t start, size_t size) {
+bool ZVirtualMemoryManager::reserve_contiguous_platform(uintptr_t start, size_t size) {
// Reserve address views
const uintptr_t marked0 = ZAddress::marked0(start);
const uintptr_t marked1 = ZAddress::marked1(start);
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/gc/z/zAddressSpaceLimit.cpp Thu Oct 24 17:24:58 2019 +0200
@@ -0,0 +1,51 @@
+/*
+ * Copyright (c) 2019, 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+#include "precompiled.hpp"
+#include "gc/z/zAddressSpaceLimit.hpp"
+#include "gc/z/zGlobals.hpp"
+#include "runtime/os.hpp"
+#include "utilities/align.hpp"
+
+static size_t address_space_limit() {
+ julong limit = 0;
+
+ if (os::has_allocatable_memory_limit(&limit)) {
+ return (size_t)limit;
+ }
+
+ // No limit
+ return SIZE_MAX;
+}
+
+size_t ZAddressSpaceLimit::mark_stack() {
+ // Allow mark stacks to occupy 10% of the address space
+ const size_t limit = address_space_limit() / 10;
+ return align_up(limit, ZMarkStackSpaceExpandSize);
+}
+
+size_t ZAddressSpaceLimit::heap_view() {
+ // Allow all heap views to occupy 50% of the address space
+ const size_t limit = address_space_limit() / 2 / ZHeapViews;
+ return align_up(limit, ZGranuleSize);
+}
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/gc/z/zAddressSpaceLimit.hpp Thu Oct 24 17:24:58 2019 +0200
@@ -0,0 +1,35 @@
+/*
+ * Copyright (c) 2019, 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+#ifndef SHARE_GC_Z_ZADDRESSSPACELIMIT_HPP
+#define SHARE_GC_Z_ZADDRESSSPACELIMIT_HPP
+
+#include "memory/allocation.hpp"
+
+class ZAddressSpaceLimit : public AllStatic {
+public:
+ static size_t mark_stack();
+ static size_t heap_view();
+};
+
+#endif // SHARE_GC_Z_ZADDRESSSPACELIMIT_HPP
--- a/src/hotspot/share/gc/z/zArguments.cpp Thu Oct 24 16:37:22 2019 +0200
+++ b/src/hotspot/share/gc/z/zArguments.cpp Thu Oct 24 17:24:58 2019 +0200
@@ -22,6 +22,7 @@
*/
#include "precompiled.hpp"
+#include "gc/z/zAddressSpaceLimit.hpp"
#include "gc/z/zArguments.hpp"
#include "gc/z/zCollectedHeap.hpp"
#include "gc/z/zWorkers.hpp"
@@ -37,6 +38,15 @@
void ZArguments::initialize() {
GCArguments::initialize();
+ // Check mark stack size
+ const size_t mark_stack_space_limit = ZAddressSpaceLimit::mark_stack();
+ if (ZMarkStackSpaceLimit > mark_stack_space_limit) {
+ if (!FLAG_IS_DEFAULT(ZMarkStackSpaceLimit)) {
+ vm_exit_during_initialization("ZMarkStackSpaceLimit too large for limited address space");
+ }
+ FLAG_SET_DEFAULT(ZMarkStackSpaceLimit, mark_stack_space_limit);
+ }
+
// Enable NUMA by default
if (FLAG_IS_DEFAULT(UseNUMA)) {
FLAG_SET_DEFAULT(UseNUMA, true);
--- a/src/hotspot/share/gc/z/zGlobals.hpp Thu Oct 24 16:37:22 2019 +0200
+++ b/src/hotspot/share/gc/z/zGlobals.hpp Thu Oct 24 17:24:58 2019 +0200
@@ -44,6 +44,23 @@
const size_t ZGranuleSizeShift = ZPlatformGranuleSizeShift;
const size_t ZGranuleSize = (size_t)1 << ZGranuleSizeShift;
+// Number of heap views
+const size_t ZHeapViews = ZPlatformHeapViews;
+
+// Virtual memory to physical memory ratio
+const size_t ZVirtualToPhysicalRatio = 16; // 16:1
+
+//
+// Page Tiers (assuming ZGranuleSize=2M)
+// -------------------------------------
+//
+// Page Size Object Size Object Alignment
+// --------------------------------------------------
+// Small 2M <= 265K MinObjAlignmentInBytes
+// Medium 32M <= 4M 4K
+// Large N x 2M > 4M 2M
+//
+
// Page types
const uint8_t ZPageTypeSmall = 0;
const uint8_t ZPageTypeMedium = 1;
--- a/src/hotspot/share/gc/z/zVirtualMemory.cpp Thu Oct 24 16:37:22 2019 +0200
+++ b/src/hotspot/share/gc/z/zVirtualMemory.cpp Thu Oct 24 17:24:58 2019 +0200
@@ -22,10 +22,13 @@
*/
#include "precompiled.hpp"
+#include "gc/z/zAddressSpaceLimit.hpp"
#include "gc/z/zGlobals.hpp"
#include "gc/z/zVirtualMemory.inline.hpp"
#include "logging/log.hpp"
#include "services/memTracker.hpp"
+#include "utilities/debug.hpp"
+#include "utilities/align.hpp"
ZVirtualMemoryManager::ZVirtualMemoryManager(size_t max_capacity) :
_manager(),
@@ -38,11 +41,9 @@
return;
}
- log_info(gc, init)("Address Space: " SIZE_FORMAT "T", ZAddressOffsetMax / K / G);
-
// Reserve address space
- if (reserve(0, ZAddressOffsetMax) < max_capacity) {
- log_error(gc)("Failed to reserve address space for Java heap");
+ if (!reserve(max_capacity)) {
+ log_error(gc)("Failed to reserve enough address space for Java heap");
return;
}
@@ -50,21 +51,92 @@
_initialized = true;
}
-size_t ZVirtualMemoryManager::reserve(uintptr_t start, size_t size) {
- if (size < ZGranuleSize) {
+size_t ZVirtualMemoryManager::reserve_discontiguous(uintptr_t start, size_t size, size_t min_range) {
+ if (size < min_range) {
+ // Too small
+ return 0;
+ }
+
+ assert(is_aligned(size, ZGranuleSize), "Misaligned");
+
+ if (reserve_contiguous_platform(start, size)) {
+ // Make the address range free
+ _manager.free(start, size);
+ return size;
+ }
+
+ const size_t half = size / 2;
+ if (half < min_range) {
// Too small
return 0;
}
- if (!reserve_platform(start, size)) {
- const size_t half = size / 2;
- return reserve(start, half) + reserve(start + half, half);
+ // Divide and conquer
+ const size_t first_part = align_down(half, ZGranuleSize);
+ const size_t second_part = size - first_part;
+ return reserve_discontiguous(start, first_part, min_range) +
+ reserve_discontiguous(start + first_part, second_part, min_range);
+}
+
+size_t ZVirtualMemoryManager::reserve_discontiguous(size_t size) {
+ // Don't try to reserve address ranges smaller than 1% of the requested size.
+ // This avoids an explosion of reservation attempts in case large parts of the
+ // address space is already occupied.
+ const size_t min_range = align_up(size / 100, ZGranuleSize);
+ size_t start = 0;
+ size_t reserved = 0;
+
+ // Reserve size somewhere between [0, ZAddressOffsetMax)
+ while (reserved < size && start < ZAddressOffsetMax) {
+ const size_t remaining = MIN2(size - reserved, ZAddressOffsetMax - start);
+ reserved += reserve_discontiguous(start, remaining, min_range);
+ start += remaining;
}
- // Make the address range free
- _manager.free(start, size);
+ return reserved;
+}
+
+bool ZVirtualMemoryManager::reserve_contiguous(size_t size) {
+ // Allow at most 8192 attempts spread evenly across [0, ZAddressOffsetMax)
+ const size_t end = ZAddressOffsetMax - size;
+ const size_t increment = align_up(end / 8192, ZGranuleSize);
+
+ for (size_t start = 0; start <= end; start += increment) {
+ if (reserve_contiguous_platform(start, size)) {
+ // Make the address range free
+ _manager.free(start, size);
+
+ // Success
+ return true;
+ }
+ }
+
+ // Failed
+ return false;
+}
- return size;
+bool ZVirtualMemoryManager::reserve(size_t max_capacity) {
+ const size_t limit = MIN2(ZAddressOffsetMax, ZAddressSpaceLimit::heap_view());
+ const size_t size = MIN2(max_capacity * ZVirtualToPhysicalRatio, limit);
+
+ size_t reserved = size;
+ bool contiguous = true;
+
+ // Prefer a contiguous address space
+ if (!reserve_contiguous(size)) {
+ // Fall back to a discontiguous address space
+ reserved = reserve_discontiguous(size);
+ contiguous = false;
+ }
+
+ log_info(gc, init)("Address Space Type: %s/%s/%s",
+ (contiguous ? "Contiguous" : "Discontiguous"),
+ (limit == ZAddressOffsetMax ? "Unrestricted" : "Restricted"),
+ (reserved == size ? "Complete" : "Degraded"));
+ log_info(gc, init)("Address Space Size: " SIZE_FORMAT "M x " SIZE_FORMAT " = " SIZE_FORMAT "M",
+ reserved / M, ZHeapViews, (reserved * ZHeapViews) / M);
+
+ return reserved >= max_capacity;
}
void ZVirtualMemoryManager::nmt_reserve(uintptr_t start, size_t size) {
--- a/src/hotspot/share/gc/z/zVirtualMemory.hpp Thu Oct 24 16:37:22 2019 +0200
+++ b/src/hotspot/share/gc/z/zVirtualMemory.hpp Thu Oct 24 17:24:58 2019 +0200
@@ -50,8 +50,12 @@
ZMemoryManager _manager;
bool _initialized;
- bool reserve_platform(uintptr_t start, size_t size);
- size_t reserve(uintptr_t start, size_t size);
+ bool reserve_contiguous_platform(uintptr_t start, size_t size);
+ bool reserve_contiguous(size_t size);
+ size_t reserve_discontiguous(uintptr_t start, size_t size, size_t min_range);
+ size_t reserve_discontiguous(size_t size);
+ bool reserve(size_t max_capacity);
+
void nmt_reserve(uintptr_t start, size_t size);
public:
--- a/test/hotspot/jtreg/vmTestbase/nsk/jvmti/Allocate/alloc001/TestDescription.java Thu Oct 24 16:37:22 2019 +0200
+++ b/test/hotspot/jtreg/vmTestbase/nsk/jvmti/Allocate/alloc001/TestDescription.java Thu Oct 24 17:24:58 2019 +0200
@@ -42,8 +42,6 @@
* @library /vmTestbase
* /test/lib
* @requires os.family != "aix"
- * @comment Test is incompatible with ZGC, due to ZGC's address space requirements.
- * @requires vm.gc != "Z"
* @run driver jdk.test.lib.FileInstaller . .
* @build nsk.jvmti.Allocate.alloc001
* @run shell alloc001.sh