RFR: 8369622: GlobalChunkPoolMutex is recursively locked during error handling

[Afshin Zafari]

On Fri, 17 Oct 2025 17:04:58 GMT, Coleen Phillimore <coleenp at openjdk.org> wrote:

> This change disables recursive locking for the ChunkPoolLocker during error handling for NMT callers.  The patch is written by Johan as an alternative to supporting another recursive locker for this lock.
> Tested with tier1-4, tier5 on aarch64 (product and debug).

Thank you for taking this PR.
I could reproduce the deadlock by this change: 

--- a/test/hotspot/gtest/nmt/test_nmt_buffer_overflow_detection.cpp
+++ b/test/hotspot/gtest/nmt/test_nmt_buffer_overflow_detection.cpp
@@ -23,6 +23,7 @@
  */
 
 #include "memory/allocation.hpp"
+#include "memory/arena.hpp"
 #include "nmt/memTracker.hpp"
 #include "runtime/os.hpp"
 #include "sanitizers/address.hpp"
@@ -142,6 +143,21 @@ DEFINE_TEST(test_corruption_on_realloc_growing, COMMON_NMT_HEAP_CORRUPTION_MESSA
 static void test_corruption_on_realloc_shrinking()  { test_corruption_on_realloc(0x11, 0x10); }
 DEFINE_TEST(test_corruption_on_realloc_shrinking, COMMON_NMT_HEAP_CORRUPTION_MESSAGE_PREFIX);
 
+
+static void test_chunkpool_lock() {
+  if (!MemTracker::enabled()) {
+    tty->print_cr("Skipped");
+    return;
+  }
+  PrintNMTStatistics = true;
+  {
+    ChunkPoolLocker cpl;
+    char* mem = (char*)os::malloc(100, mtTest);
+    memset(mem - 16, 0, 100 + 16 + 2);
+    os::free(mem);
+  }
+}
+DEFINE_TEST(test_chunkpool_lock, COMMON_NMT_HEAP_CORRUPTION_MESSAGE_PREFIX);
 ///////



We can add it to the tests if you found it useful.

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PR Review: https://git.openjdk.org/jdk/pull/27869#pullrequestreview-3360133902