1 files changed, 46 insertions, 0 deletions
diff --git a/memory/mozjemalloc_info/MozjemallocInfo.cpp b/memory/mozjemalloc_info/MozjemallocInfo.cpp
new file mode 100644
index 0000000000..0795be8047
--- /dev/null
+++ b/memory/mozjemalloc_info/MozjemallocInfo.cpp
@@ -0,0 +1,46 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "mozmemory.h"
+
+/*
+ * Print the configured size classes which we can then use to update
+ * documentation.
+ */
+int main() {
+  jemalloc_stats_t stats;
+
+  const size_t num_bins = jemalloc_stats_num_bins();
+  const size_t MAX_NUM_BINS = 100;
+  if (num_bins > MAX_NUM_BINS) {
+    fprintf(stderr, "Exceeded maximum number of jemalloc stats bins");
+    return 1;
+  }
+  jemalloc_bin_stats_t bin_stats[MAX_NUM_BINS] = {{0}};
+  jemalloc_stats(&stats, bin_stats);
+
+  printf("Page size:    %5zu\n", stats.page_size);
+  printf("Chunk size:   %5zuKiB\n", stats.chunksize / 1024);
+
+  printf("Quantum:      %5zu\n", stats.quantum);
+  printf("Quantum max:  %5zu\n", stats.quantum_max);
+  printf("Sub-page max: %5zu\n", stats.page_size / 2);
+  printf("Large max:    %5zuKiB\n", stats.large_max / 1024);
+
+  printf("\nBin stats:\n");
+  for (unsigned i = 0; i < num_bins; i++) {
+    auto& bin = bin_stats[i];
+    if (bin.size) {
+      printf("  Bin %5zu has runs of %3zuKiB\n", bin.size,
+             bin.bytes_per_run / 1024);
+    }
+  }
+
+  return EXIT_SUCCESS;
+}