8313593: Generational ZGC: NMT assert when the heap fails to expand

Reviewed-by: eosterlund Backport-of: 19e2c8c321823c056091e6e9f6c3d0db7ba9ec2b
corretto · Aug 4, 2023 · 4273487 · 4273487
1 parent fd789db
commit 4273487
Showing 1 changed file with 6 additions and 2 deletions.
diff --git a/src/hotspot/share/gc/z/zPhysicalMemory.cpp b/src/hotspot/share/gc/z/zPhysicalMemory.cpp
@@ -309,7 +309,9 @@ bool ZPhysicalMemoryManager::commit(ZPhysicalMemory& pmem) {
     const size_t committed = _backing.commit(segment.start(), segment.size());
 
     // Register with NMT
-    ZNMT::commit(segment.start(), committed);
+    if (committed > 0) {
+      ZNMT::commit(segment.start(), committed);
+    }
 
     // Register committed segment
     if (!pmem.commit_segment(i, committed)) {
@@ -335,7 +337,9 @@ bool ZPhysicalMemoryManager::uncommit(ZPhysicalMemory& pmem) {
     const size_t uncommitted = _backing.uncommit(segment.start(), segment.size());
 
     // Unregister with NMT
-    ZNMT::uncommit(segment.start(), uncommitted);
+    if (uncommitted > 0) {
+      ZNMT::uncommit(segment.start(), uncommitted);
+    }
 
     // Deregister uncommitted segment
     if (!pmem.uncommit_segment(i, uncommitted)) {