Merge "Add new mallopt M_LOG_STATS." am: 90e2827762

Original change: https://android-review.googlesource.com/c/platform/bionic/+/2585453

Change-Id: I86bd0363a9cc43bb6b0de32b95e1b68945c1d212
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>

libc/bionic/jemalloc_wrapper.cpp

@@ -19,10 +19,20 @@
 #include <sys/param.h>
 #include <unistd.h>
 
+#include <async_safe/log.h>
 #include <private/MallocXmlElem.h>
 
 #include "jemalloc.h"
 
+__BEGIN_DECLS
+
+size_t je_mallinfo_narenas();
+size_t je_mallinfo_nbins();
+struct mallinfo je_mallinfo_arena_info(size_t);
+struct mallinfo je_mallinfo_bin_info(size_t, size_t);
+
+__END_DECLS
+
 void* je_pvalloc(size_t bytes) {
   size_t pagesize = getpagesize();
   size_t size = __BIONIC_ALIGN(bytes, pagesize);
@@ -121,19 +131,36 @@ int je_mallopt(int param, int value) {
       return 0;
     }
     return 1;
+  } else if (param == M_LOG_STATS) {
+    for (size_t i = 0; i < je_mallinfo_narenas(); i++) {
+      struct mallinfo mi = je_mallinfo_arena_info(i);
+      if (mi.hblkhd != 0) {
+        async_safe_format_log(ANDROID_LOG_INFO, "jemalloc",
+                              "Arena %zu: large bytes %zu huge bytes %zu bin bytes %zu", i,
+                              mi.ordblks, mi.uordblks, mi.fsmblks);
+
+        for (size_t j = 0; j < je_mallinfo_nbins(); j++) {
+          struct mallinfo mi = je_mallinfo_bin_info(i, j);
+          if (mi.ordblks != 0) {
+            size_t total_allocs = 1;
+            if (mi.uordblks > mi.fordblks) {
+              total_allocs = mi.uordblks - mi.fordblks;
+            }
+            size_t bin_size = mi.ordblks / total_allocs;
+            async_safe_format_log(
+                ANDROID_LOG_INFO, "jemalloc",
+                "  Bin %zu (%zu bytes): allocated bytes %zu nmalloc %zu ndalloc %zu", j, bin_size,
+                mi.ordblks, mi.uordblks, mi.fordblks);
+          }
+        }
+      }
+    }
+    return 1;
   }
+
   return 0;
 }
 
-__BEGIN_DECLS
-
-size_t je_mallinfo_narenas();
-size_t je_mallinfo_nbins();
-struct mallinfo je_mallinfo_arena_info(size_t);
-struct mallinfo je_mallinfo_bin_info(size_t, size_t);
-
-__END_DECLS
-
 int je_malloc_info(int options, FILE* fp) {
   if (options != 0) {
     errno = EINVAL;

libc/include/malloc.h

@@ -319,6 +319,16 @@ enum HeapTaggingLevel {
 #define M_HEAP_TAGGING_LEVEL_SYNC M_HEAP_TAGGING_LEVEL_SYNC
 };
 
+/**
+ * mallopt() option to print human readable statistics about the memory
+ * allocator to the log. There is no format for this data, each allocator
+ * can use a different format, and the data that is printed can
+ * change at any time. This is expected to be used as a debugging aid.
+ *
+ * Available since API level 35.
+ */
+#define M_LOG_STATS (-205)
+
 /**
  * [mallopt(3)](http://man7.org/linux/man-pages/man3/mallopt.3.html) modifies
  * heap behavior. Values of `__option` are the `M_` constants from this header.

tests/malloc_test.cpp

@@ -708,6 +708,15 @@ TEST(malloc, mallopt_purge_all) {
 #endif
 }
 
+TEST(malloc, mallopt_log_stats) {
+#if defined(__BIONIC__)
+  SKIP_WITH_HWASAN << "hwasan does not implement mallopt";
+  ASSERT_EQ(1, mallopt(M_LOG_STATS, 0));
+#else
+  GTEST_SKIP() << "bionic-only test";
+#endif
+}
+
 // Verify that all of the mallopt values are unique.
 TEST(malloc, mallopt_unique_params) {
 #if defined(__BIONIC__)
@@ -722,6 +731,7 @@ TEST(malloc, mallopt_unique_params) {
       std::make_pair(M_TSDS_COUNT_MAX, "M_TSDS_COUNT_MAX"),
       std::make_pair(M_BIONIC_ZERO_INIT, "M_BIONIC_ZERO_INIT"),
       std::make_pair(M_BIONIC_SET_HEAP_TAGGING_LEVEL, "M_BIONIC_SET_HEAP_TAGGING_LEVEL"),
+      std::make_pair(M_LOG_STATS, "M_LOG_STATS"),
   };
 
   std::unordered_map<int, std::string> all_params;