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src/hotspot/share/gc/z/zPhysicalMemory.cpp
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@@ -25,106 +25,230 @@
#include "gc/z/zAddress.inline.hpp"
#include "gc/z/zGlobals.hpp"
#include "gc/z/zLargePages.inline.hpp"
#include "gc/z/zNUMA.inline.hpp"
#include "gc/z/zPhysicalMemory.inline.hpp"
+#include "logging/log.hpp"
+#include "runtime/globals.hpp"
#include "runtime/init.hpp"
#include "runtime/os.hpp"
#include "services/memTracker.hpp"
#include "utilities/align.hpp"
#include "utilities/debug.hpp"
#include "utilities/globalDefinitions.hpp"
+#include "utilities/powerOfTwo.hpp"
ZPhysicalMemory::ZPhysicalMemory() :
+ _nsegments_max(0),
_nsegments(0),
_segments(NULL) {}
ZPhysicalMemory::ZPhysicalMemory(const ZPhysicalMemorySegment& segment) :
+ _nsegments_max(0),
_nsegments(0),
_segments(NULL) {
add_segment(segment);
}
ZPhysicalMemory::ZPhysicalMemory(const ZPhysicalMemory& pmem) :
+ _nsegments_max(0),
_nsegments(0),
_segments(NULL) {
-
- // Copy segments
- for (size_t i = 0; i < pmem.nsegments(); i++) {
- add_segment(pmem.segment(i));
- }
+ add_segments(pmem);
}
const ZPhysicalMemory& ZPhysicalMemory::operator=(const ZPhysicalMemory& pmem) {
// Free segments
delete [] _segments;
_segments = NULL;
+ _nsegments_max = 0;
_nsegments = 0;
// Copy segments
- for (size_t i = 0; i < pmem.nsegments(); i++) {
- add_segment(pmem.segment(i));
- }
+ add_segments(pmem);
return *this;
}
ZPhysicalMemory::~ZPhysicalMemory() {
delete [] _segments;
- _segments = NULL;
- _nsegments = 0;
}
size_t ZPhysicalMemory::size() const {
size_t size = 0;
- for (size_t i = 0; i < _nsegments; i++) {
+ for (uint32_t i = 0; i < _nsegments; i++) {
size += _segments[i].size();
}
return size;
}
+void ZPhysicalMemory::insert_segment(uint32_t index, uintptr_t start, size_t size, bool committed) {
+ assert(index <= _nsegments, "Invalid index");
+
+ ZPhysicalMemorySegment* const from_segments = _segments;
+
+ if (_nsegments + 1 > _nsegments_max) {
+ // Resize array
+ _nsegments_max = round_up_power_of_2(_nsegments_max + 1);
+ _segments = new ZPhysicalMemorySegment[_nsegments_max];
+
+ // Copy segments before index
+ for (uint32_t i = 0; i < index; i++) {
+ _segments[i] = from_segments[i];
+ }
+ }
+
+ // Copy/Move segments after index
+ for (uint32_t i = _nsegments; i > index; i--) {
+ _segments[i] = from_segments[i - 1];
+ }
+
+ // Insert new segment
+ _segments[index] = ZPhysicalMemorySegment(start, size, committed);
+ _nsegments++;
+
+ // Delete old array
+ if (from_segments != _segments) {
+ delete [] from_segments;
+ }
+}
+
+void ZPhysicalMemory::replace_segment(uint32_t index, uintptr_t start, size_t size, bool committed) {
+ assert(index < _nsegments, "Invalid index");
+ _segments[index] = ZPhysicalMemorySegment(start, size, committed);;
+}
+
+void ZPhysicalMemory::remove_segment(uint32_t index) {
+ assert(index < _nsegments, "Invalid index");
+
+ // Move segments after index
+ for (uint32_t i = index + 1; i < _nsegments; i++) {
+ _segments[i - 1] = _segments[i];
+ }
+
+ _nsegments--;
+}
+
+void ZPhysicalMemory::add_segments(const ZPhysicalMemory& pmem) {
+ for (uint32_t i = 0; i < pmem.nsegments(); i++) {
+ add_segment(pmem.segment(i));
+ }
+}
+
+void ZPhysicalMemory::transfer_segments(ZPhysicalMemory& pmem) {
+ add_segments(pmem);
+ pmem = ZPhysicalMemory();
+}
+
+static bool is_mergable(const ZPhysicalMemorySegment& before, const ZPhysicalMemorySegment& after) {
+ return before.end() == after.start() && before.is_committed() == after.is_committed();
+}
+
void ZPhysicalMemory::add_segment(const ZPhysicalMemorySegment& segment) {
- // Try merge with last segment
- if (_nsegments > 0) {
- ZPhysicalMemorySegment& last = _segments[_nsegments - 1];
- assert(last.end() <= segment.start(), "Segments added out of order");
- if (last.end() == segment.start()) {
- last = ZPhysicalMemorySegment(last.start(), last.size() + segment.size());
+ // Insert segments in address order, merge segments when possible
+ for (uint32_t i = _nsegments; i > 0; i--) {
+ const uint32_t current = i - 1;
+
+ if (_segments[current].end() <= segment.start()) {
+ if (is_mergable(_segments[current], segment)) {
+ if (current + 1 < _nsegments && is_mergable(segment, _segments[current + 1])) {
+ // Merge with end of current segment and start of next segment
+ const size_t start = _segments[current].start();
+ const size_t size = _segments[current].size() + segment.size() + _segments[current + 1].size();
+ replace_segment(current, start, size, segment.is_committed());
+ remove_segment(current + 1);
+ return;
+ }
+
+ // Merge with end of current segment
+ const size_t start = _segments[current].start();
+ const size_t size = _segments[current].size() + segment.size();
+ replace_segment(current, start, size, segment.is_committed());
+ return;
+ } else if (current + 1 < _nsegments && is_mergable(segment, _segments[current + 1])) {
+ // Merge with start of next segment
+ const size_t start = segment.start();
+ const size_t size = segment.size() + _segments[current + 1].size();
+ replace_segment(current + 1, start, size, segment.is_committed());
+ return;
+ }
+
+ // Insert after current segment
+ insert_segment(current + 1, segment.start(), segment.size(), segment.is_committed());
return;
}
}
- // Resize array
- ZPhysicalMemorySegment* const old_segments = _segments;
- _segments = new ZPhysicalMemorySegment[_nsegments + 1];
- for (size_t i = 0; i < _nsegments; i++) {
- _segments[i] = old_segments[i];
+ if (_nsegments > 0 && is_mergable(segment, _segments[0])) {
+ // Merge with start of first segment
+ const size_t start = segment.start();
+ const size_t size = segment.size() + _segments[0].size();
+ replace_segment(0, start, size, segment.is_committed());
+ return;
}
- delete [] old_segments;
- // Add new segment
- _segments[_nsegments] = segment;
- _nsegments++;
+ // Insert before first segment
+ insert_segment(0, segment.start(), segment.size(), segment.is_committed());
+}
+
+bool ZPhysicalMemory::commit_segment(uint32_t index, size_t size) {
+ assert(index < _nsegments, "Invalid index");
+ assert(size <= _segments[index].size(), "Invalid size");
+ assert(!_segments[index].is_committed(), "Invalid state");
+
+ if (size == _segments[index].size()) {
+ // Completely committed
+ _segments[index].set_committed(true);
+ return true;
+ }
+
+ if (size > 0) {
+ // Partially committed, split segment
+ insert_segment(index + 1, _segments[index].start() + size, _segments[index].size() - size, false /* committed */);
+ replace_segment(index, _segments[index].start(), size, true /* committed */);
+ }
+
+ return false;
+}
+
+bool ZPhysicalMemory::uncommit_segment(uint32_t index, size_t size) {
+ assert(index < _nsegments, "Invalid index");
+ assert(size <= _segments[index].size(), "Invalid size");
+ assert(_segments[index].is_committed(), "Invalid state");
+
+ if (size == _segments[index].size()) {
+ // Completely uncommitted
+ _segments[index].set_committed(false);
+ return true;
+ }
+
+ if (size > 0) {
+ // Partially uncommitted, split segment
+ insert_segment(index + 1, _segments[index].start() + size, _segments[index].size() - size, true /* committed */);
+ replace_segment(index, _segments[index].start(), size, false /* committed */);
+ }
+
+ return false;
}
ZPhysicalMemory ZPhysicalMemory::split(size_t size) {
ZPhysicalMemory pmem;
- size_t nsegments = 0;
+ uint32_t nsegments = 0;
- for (size_t i = 0; i < _nsegments; i++) {
+ for (uint32_t i = 0; i < _nsegments; i++) {
const ZPhysicalMemorySegment& segment = _segments[i];
if (pmem.size() < size) {
if (pmem.size() + segment.size() <= size) {
// Transfer segment
pmem.add_segment(segment);
} else {
// Split segment
const size_t split_size = size - pmem.size();
- pmem.add_segment(ZPhysicalMemorySegment(segment.start(), split_size));
- _segments[nsegments++] = ZPhysicalMemorySegment(segment.start() + split_size, segment.size() - split_size);
+ pmem.add_segment(ZPhysicalMemorySegment(segment.start(), split_size, segment.is_committed()));
+ _segments[nsegments++] = ZPhysicalMemorySegment(segment.start() + split_size, segment.size() - split_size, segment.is_committed());
}
} else {
// Keep segment
_segments[nsegments++] = segment;
}
@@ -133,29 +257,72 @@
_nsegments = nsegments;
return pmem;
}
+ZPhysicalMemory ZPhysicalMemory::split_committed() {
+ ZPhysicalMemory pmem;
+ uint32_t nsegments = 0;
+
+ for (uint32_t i = 0; i < _nsegments; i++) {
+ const ZPhysicalMemorySegment& segment = _segments[i];
+ if (segment.is_committed()) {
+ // Transfer segment
+ pmem.add_segment(segment);
+ } else {
+ // Keep segment
+ _segments[nsegments++] = segment;
+ }
+ }
+
+ _nsegments = nsegments;
+
+ return pmem;
+}
+
ZPhysicalMemoryManager::ZPhysicalMemoryManager(size_t max_capacity) :
_backing(max_capacity) {
- // Register everything as uncommitted
- _uncommitted.free(0, max_capacity);
+ // Make the whole range free
+ _manager.free(0, max_capacity);
}
bool ZPhysicalMemoryManager::is_initialized() const {
return _backing.is_initialized();
}
-void ZPhysicalMemoryManager::warn_commit_limits(size_t max) const {
- _backing.warn_commit_limits(max);
+void ZPhysicalMemoryManager::warn_commit_limits(size_t max_capacity) const {
+ _backing.warn_commit_limits(max_capacity);
}
-bool ZPhysicalMemoryManager::supports_uncommit() {
+bool ZPhysicalMemoryManager::should_enable_uncommit(size_t min_capacity, size_t max_capacity) {
assert(!is_init_completed(), "Invalid state");
- // Test if uncommit is supported by uncommitting and then re-committing a granule
- return commit(uncommit(ZGranuleSize)) == ZGranuleSize;
+ // If uncommit is not explicitly disabled, max capacity is greater than
+ // min capacity, and uncommit is supported by the platform, then uncommit
+ // will be enabled.
+ if (!ZUncommit) {
+ log_info(gc, init)("Uncommit: Disabled");
+ return false;
+ }
+
+ if (max_capacity == min_capacity) {
+ log_info(gc, init)("Uncommit: Implicitly Disabled (-Xms equals -Xmx)");
+ return false;
+ }
+
+ // Test if uncommit is supported by the operating system by committing
+ // and then uncommitting the a granule.
+ ZPhysicalMemory pmem(ZPhysicalMemorySegment(0, ZGranuleSize, false /* committed */));
+ if (!commit(pmem) || !uncommit(pmem)) {
+ log_info(gc, init)("Uncommit: Implicitly Disabled (Not supported by operating system)");
+ return false;
+ }
+
+ log_info(gc, init)("Uncommit: Enabled");
+ log_info(gc, init)("Uncommit Delay: " UINTX_FORMAT "s", ZUncommitDelay);
+
+ return true;
}
void ZPhysicalMemoryManager::nmt_commit(const ZPhysicalMemory& pmem, uintptr_t offset) const {
// From an NMT point of view we treat the first heap view (marked0) as committed
const uintptr_t addr = ZAddress::marked0(offset);
@@ -170,115 +337,106 @@
Tracker tracker(Tracker::uncommit);
tracker.record((address)addr, size);
}
}
-size_t ZPhysicalMemoryManager::commit(size_t size) {
- size_t committed = 0;
+void ZPhysicalMemoryManager::alloc(ZPhysicalMemory& pmem, size_t size) {
+ assert(is_aligned(size, ZGranuleSize), "Invalid size");
- // Fill holes in the backing memory
- while (committed < size) {
+ // Allocate segments
+ while (size > 0) {
size_t allocated = 0;
- const size_t remaining = size - committed;
- const uintptr_t start = _uncommitted.alloc_from_front_at_most(remaining, &allocated);
- if (start == UINTPTR_MAX) {
- // No holes to commit
- break;
- }
-
- // Try commit hole
- const size_t filled = _backing.commit(start, allocated);
- if (filled > 0) {
- // Successful or partialy successful
- _committed.free(start, filled);
- committed += filled;
- }
- if (filled < allocated) {
- // Failed or partialy failed
- _uncommitted.free(start + filled, allocated - filled);
- return committed;
- }
+ const uintptr_t start = _manager.alloc_from_front_at_most(size, &allocated);
+ assert(start != UINTPTR_MAX, "Allocation should never fail");
+ pmem.add_segment(ZPhysicalMemorySegment(start, allocated, false /* committed */));
+ size -= allocated;
}
-
- return committed;
}
-size_t ZPhysicalMemoryManager::uncommit(size_t size) {
- size_t uncommitted = 0;
-
- // Punch holes in backing memory
- while (uncommitted < size) {
- size_t allocated = 0;
- const size_t remaining = size - uncommitted;
- const uintptr_t start = _committed.alloc_from_back_at_most(remaining, &allocated);
- assert(start != UINTPTR_MAX, "Allocation should never fail");
-
- // Try punch hole
- const size_t punched = _backing.uncommit(start, allocated);
- if (punched > 0) {
- // Successful or partialy successful
- _uncommitted.free(start, punched);
- uncommitted += punched;
- }
- if (punched < allocated) {
- // Failed or partialy failed
- _committed.free(start + punched, allocated - punched);
- return uncommitted;
- }
+void ZPhysicalMemoryManager::free(const ZPhysicalMemory& pmem) {
+ // Free segments
+ for (uint32_t i = 0; i < pmem.nsegments(); i++) {
+ const ZPhysicalMemorySegment& segment = pmem.segment(i);
+ _manager.free(segment.start(), segment.size());
}
-
- return uncommitted;
}
-ZPhysicalMemory ZPhysicalMemoryManager::alloc(size_t size) {
- assert(is_aligned(size, ZGranuleSize), "Invalid size");
-
- ZPhysicalMemory pmem;
+bool ZPhysicalMemoryManager::commit(ZPhysicalMemory& pmem) {
+ // Commit segments
+ for (uint32_t i = 0; i < pmem.nsegments(); i++) {
+ const ZPhysicalMemorySegment& segment = pmem.segment(i);
+ if (segment.is_committed()) {
+ // Segment already committed
+ continue;
+ }
- // Allocate segments
- for (size_t allocated = 0; allocated < size; allocated += ZGranuleSize) {
- const uintptr_t start = _committed.alloc_from_front(ZGranuleSize);
- assert(start != UINTPTR_MAX, "Allocation should never fail");
- pmem.add_segment(ZPhysicalMemorySegment(start, ZGranuleSize));
+ // Commit segment
+ const size_t committed = _backing.commit(segment.start(), segment.size());
+ if (!pmem.commit_segment(i, committed)) {
+ // Failed or partially failed
+ return false;
+ }
}
- return pmem;
+ // Success
+ return true;
}
-void ZPhysicalMemoryManager::free(const ZPhysicalMemory& pmem) {
- const size_t nsegments = pmem.nsegments();
-
- // Free segments
- for (size_t i = 0; i < nsegments; i++) {
+bool ZPhysicalMemoryManager::uncommit(ZPhysicalMemory& pmem) {
+ // Commit segments
+ for (uint32_t i = 0; i < pmem.nsegments(); i++) {
const ZPhysicalMemorySegment& segment = pmem.segment(i);
- _committed.free(segment.start(), segment.size());
+ if (!segment.is_committed()) {
+ // Segment already uncommitted
+ continue;
+ }
+
+ // Uncommit segment
+ const size_t uncommitted = _backing.uncommit(segment.start(), segment.size());
+ if (!pmem.uncommit_segment(i, uncommitted)) {
+ // Failed or partially failed
+ return false;
+ }
}
+
+ // Success
+ return true;
}
void ZPhysicalMemoryManager::pretouch_view(uintptr_t addr, size_t size) const {
const size_t page_size = ZLargePages::is_explicit() ? ZGranuleSize : os::vm_page_size();
os::pretouch_memory((void*)addr, (void*)(addr + size), page_size);
}
-void ZPhysicalMemoryManager::map_view(const ZPhysicalMemory& pmem, uintptr_t addr) const {
- const size_t nsegments = pmem.nsegments();
+bool ZPhysicalMemoryManager::map_view(const ZPhysicalMemory& pmem, uintptr_t addr) const {
size_t size = 0;
// Map segments
- for (size_t i = 0; i < nsegments; i++) {
+ for (uint32_t i = 0; i < pmem.nsegments(); i++) {
const ZPhysicalMemorySegment& segment = pmem.segment(i);
- _backing.map(addr + size, segment.size(), segment.start());
+ if (!_backing.map(addr + size, segment.size(), segment.start())) {
+ // Failed to map segment
+ if (size > 0) {
+ // Unmap successfully mapped segments
+ _backing.unmap(addr, size);
+ }
+
+ return false;
+ }
size += segment.size();
}
// Setup NUMA interleaving for large pages
if (ZNUMA::is_enabled() && ZLargePages::is_explicit()) {
// To get granule-level NUMA interleaving when using large pages,
// we simply let the kernel interleave the memory for us at page
// fault time.
os::numa_make_global((char*)addr, size);
}
+
+ // Success
+ return true;
}
void ZPhysicalMemoryManager::unmap_view(const ZPhysicalMemory& pmem, uintptr_t addr) const {
_backing.unmap(addr, pmem.size());
}
@@ -293,22 +451,36 @@
pretouch_view(ZAddress::marked1(offset), size);
pretouch_view(ZAddress::remapped(offset), size);
}
}
-void ZPhysicalMemoryManager::map(const ZPhysicalMemory& pmem, uintptr_t offset) const {
+bool ZPhysicalMemoryManager::map(const ZPhysicalMemory& pmem, uintptr_t offset) const {
if (ZVerifyViews) {
// Map good view
- map_view(pmem, ZAddress::good(offset));
+ if (!map_view(pmem, ZAddress::good(offset))) {
+ fatal("Failed to map memory");
+ }
} else {
// Map all views
- map_view(pmem, ZAddress::marked0(offset));
- map_view(pmem, ZAddress::marked1(offset));
- map_view(pmem, ZAddress::remapped(offset));
+ if (!map_view(pmem, ZAddress::marked0(offset))) {
+ return false;
+ }
+ if (!map_view(pmem, ZAddress::marked1(offset))) {
+ unmap_view(pmem, ZAddress::marked0(offset));
+ return false;
+ }
+ if (!map_view(pmem, ZAddress::remapped(offset))) {
+ unmap_view(pmem, ZAddress::marked1(offset));
+ unmap_view(pmem, ZAddress::marked0(offset));
+ return false;
+ }
}
nmt_commit(pmem, offset);
+
+ // Success
+ return true;
}
void ZPhysicalMemoryManager::unmap(const ZPhysicalMemory& pmem, uintptr_t offset) const {
nmt_uncommit(pmem, offset);
@@ -324,11 +496,13 @@
}
void ZPhysicalMemoryManager::debug_map(const ZPhysicalMemory& pmem, uintptr_t offset) const {
// Map good view
assert(ZVerifyViews, "Should be enabled");
- map_view(pmem, ZAddress::good(offset));
+ if (!map_view(pmem, ZAddress::good(offset))) {
+ fatal("Failed to map memory");
+ }
}
void ZPhysicalMemoryManager::debug_unmap(const ZPhysicalMemory& pmem, uintptr_t offset) const {
// Unmap good view
assert(ZVerifyViews, "Should be enabled");
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