diff --git a/src/hotspot/share/nmt/vmatree.cpp b/src/hotspot/share/nmt/vmatree.cpp
index 3795376d476..65a5bdb94ae 100644
--- a/src/hotspot/share/nmt/vmatree.cpp
+++ b/src/hotspot/share/nmt/vmatree.cpp
@@ -24,6 +24,7 @@
*/
#include "precompiled.hpp"
+#include "logging/log.hpp"
#include "nmt/vmatree.hpp"
#include "utilities/growableArray.hpp"
@@ -34,7 +35,9 @@ const char* VMATree::statetype_strings[3] = {
};
VMATree::SummaryDiff VMATree::register_mapping(position A, position B, StateType state,
- const RegionData& metadata) {
+ const RegionData& metadata, bool use_tag_inplace) {
+ assert(!use_tag_inplace || metadata.mem_tag == mtNone,
+ "If using use_tag_inplace, then the supplied tag should be mtNone, was instead: %s", NMTUtil::tag_to_name(metadata.mem_tag));
if (A == B) {
// A 0-sized mapping isn't worth recording.
return SummaryDiff();
@@ -55,6 +58,10 @@ VMATree::SummaryDiff VMATree::register_mapping(position A, position B, StateType
AddressState LEQ_A;
TreapNode* leqA_n = _tree.closest_leq(A);
if (leqA_n == nullptr) {
+ assert(!use_tag_inplace, "Cannot use the tag inplace if no pre-existing tag exists. From: " PTR_FORMAT " To: " PTR_FORMAT, A, B);
+ if (use_tag_inplace) {
+ log_debug(nmt)("Cannot use the tag inplace if no pre-existing tag exists. From: " PTR_FORMAT " To: " PTR_FORMAT, A, B);
+ }
// No match. We add the A node directly, unless it would have no effect.
if (!stA.is_noop()) {
_tree.upsert(A, stA);
@@ -62,6 +69,17 @@ VMATree::SummaryDiff VMATree::register_mapping(position A, position B, StateType
} else {
LEQ_A_found = true;
LEQ_A = AddressState{leqA_n->key(), leqA_n->val()};
+ StateType leqA_state = leqA_n->val().out.type();
+ StateType new_state = stA.out.type();
+ // If we specify use_tag_inplace then the new region takes over the current tag instead of the tag in metadata.
+ // This is important because the VirtualMemoryTracker API doesn't require supplying the tag for some operations.
+ if (use_tag_inplace) {
+ assert(leqA_n->val().out.type() != StateType::Released, "Should not use inplace the tag of a released region");
+ MemTag tag = leqA_n->val().out.mem_tag();
+ stA.out.set_tag(tag);
+ stB.in.set_tag(tag);
+ }
+
// Unless we know better, let B's outgoing state be the outgoing state of the node at or preceding A.
// Consider the case where the found node is the start of a region enclosing [A,B)
stB.out = leqA_n->val().out;
diff --git a/src/hotspot/share/nmt/vmatree.hpp b/src/hotspot/share/nmt/vmatree.hpp
index 55399e51b9d..cfb3c8ab524 100644
--- a/src/hotspot/share/nmt/vmatree.hpp
+++ b/src/hotspot/share/nmt/vmatree.hpp
@@ -66,7 +66,7 @@ public:
return statetype_strings[static_cast<uint8_t>(type)];
}
- // Each point has some stack and a flag associated with it.
+ // Each point has some stack and a tag associated with it.
struct RegionData {
const NativeCallStackStorage::StackIndex stack_idx;
const MemTag mem_tag;
@@ -88,30 +88,34 @@ private:
struct IntervalState {
private:
// Store the type and mem_tag as two bytes
- uint8_t type_flag[2];
+ uint8_t type_tag[2];
NativeCallStackStorage::StackIndex sidx;
public:
- IntervalState() : type_flag{0,0}, sidx() {}
+ IntervalState() : type_tag{0,0}, sidx() {}
IntervalState(const StateType type, const RegionData data) {
assert(!(type == StateType::Released) || data.mem_tag == mtNone, "Released type must have memory tag mtNone");
- type_flag[0] = static_cast<uint8_t>(type);
- type_flag[1] = static_cast<uint8_t>(data.mem_tag);
+ type_tag[0] = static_cast<uint8_t>(type);
+ type_tag[1] = static_cast<uint8_t>(data.mem_tag);
sidx = data.stack_idx;
}
StateType type() const {
- return static_cast<StateType>(type_flag[0]);
+ return static_cast<StateType>(type_tag[0]);
}
MemTag mem_tag() const {
- return static_cast<MemTag>(type_flag[1]);
+ return static_cast<MemTag>(type_tag[1]);
}
RegionData regiondata() const {
return RegionData{sidx, mem_tag()};
}
+ void set_tag(MemTag tag) {
+ type_tag[1] = static_cast<uint8_t>(tag);
+ }
+
NativeCallStackStorage::StackIndex stack() const {
return sidx;
}
@@ -167,14 +171,20 @@ public:
}
};
- SummaryDiff register_mapping(position A, position B, StateType state, const RegionData& metadata);
+ private:
+ SummaryDiff register_mapping(position A, position B, StateType state, const RegionData& metadata, bool use_tag_inplace = false);
+ public:
SummaryDiff reserve_mapping(position from, position sz, const RegionData& metadata) {
- return register_mapping(from, from + sz, StateType::Reserved, metadata);
+ return register_mapping(from, from + sz, StateType::Reserved, metadata, false);
}
- SummaryDiff commit_mapping(position from, position sz, const RegionData& metadata) {
- return register_mapping(from, from + sz, StateType::Committed, metadata);
+ SummaryDiff commit_mapping(position from, position sz, const RegionData& metadata, bool use_tag_inplace = false) {
+ return register_mapping(from, from + sz, StateType::Committed, metadata, use_tag_inplace);
+ }
+
+ SummaryDiff uncommit_mapping(position from, position sz, const RegionData& metadata) {
+ return register_mapping(from, from + sz, StateType::Reserved, metadata, true);
}
SummaryDiff release_mapping(position from, position sz) {
diff --git a/test/hotspot/gtest/nmt/test_vmatree.cpp b/test/hotspot/gtest/nmt/test_vmatree.cpp
index 08b4340ae4f..7a5a98b7863 100644
--- a/test/hotspot/gtest/nmt/test_vmatree.cpp
+++ b/test/hotspot/gtest/nmt/test_vmatree.cpp
@@ -171,7 +171,6 @@ public:
};
-
TEST_VM_F(NMTVMATreeTest, OverlappingReservationsResultInTwoNodes) {
VMATree::RegionData rd{si[0], mtTest};
Tree tree;
@@ -181,6 +180,23 @@ TEST_VM_F(NMTVMATreeTest, OverlappingReservationsResultInTwoNodes) {
EXPECT_EQ(2, count_nodes(tree));
}
+TEST_VM_F(NMTVMATreeTest, UseFlagInplace) {
+ Tree tree;
+ VMATree::RegionData rd1(si[0], mtTest);
+ VMATree::RegionData rd2(si[1], mtNone);
+ tree.reserve_mapping(0, 100, rd1);
+ tree.commit_mapping(20, 50, rd2, true);
+ tree.uncommit_mapping(30, 10, rd2);
+ tree.visit_in_order([&](Node* node) {
+ if (node->key() != 100) {
+ EXPECT_EQ(mtTest, node->val().out.mem_tag()) << "failed at: " << node->key();
+ if (node->key() != 20 && node->key() != 40) {
+ EXPECT_EQ(VMATree::StateType::Reserved, node->val().out.type());
+ }
+ }
+ });
+}
+
// Low-level tests inspecting the state of the tree.
TEST_VM_F(NMTVMATreeTest, LowLevel) {
adjacent_2_nodes(VMATree::empty_regiondata);