Add a couple of new benchmarks.

Add a calloc benchmark to make sure that a native allocator isn't
doing anything incorrectly when zero'ing memory.

Also add a fork call benchmark to verify that the time to make a
fork call isn't increasing.

Test: Ran benchmarks on walleye and verified that the numbers are not
Test: too variable between runs.
Change-Id: I61d289d277f85ac432a315e539cf6391ea036866

1 files changed, 35 insertions, 0 deletions

diff --git a/benchmarks/stdlib_benchmark.cpp b/benchmarks/stdlib_benchmark.cpp
index 61b51fa54..45b953f61 100644
--- a/benchmarks/stdlib_benchmark.cpp
+++ b/benchmarks/stdlib_benchmark.cpp
@@ -59,6 +59,41 @@ static void BM_stdlib_malloc_free_decay1(benchmark::State& state) {
 BIONIC_BENCHMARK_WITH_ARG(BM_stdlib_malloc_free_decay1, "AT_COMMON_SIZES");
 #endif
 
+static void CallocFree(benchmark::State& state) {
+  const size_t nbytes = state.range(0);
+  int pagesize = getpagesize();
+
+  for (auto _ : state) {
+    void* ptr;
+    benchmark::DoNotOptimize(ptr = calloc(1, nbytes));
+    MakeAllocationResident(ptr, nbytes, pagesize);
+    free(ptr);
+  }
+
+  state.SetBytesProcessed(uint64_t(state.iterations()) * uint64_t(nbytes));
+}
+
+static void BM_stdlib_calloc_free_default(benchmark::State& state) {
+#if defined(__BIONIC__)
+  // The default is expected to be a zero decay time.
+  mallopt(M_DECAY_TIME, 0);
+#endif
+
+  CallocFree(state);
+}
+BIONIC_BENCHMARK_WITH_ARG(BM_stdlib_calloc_free_default, "AT_COMMON_SIZES");
+
+#if defined(__BIONIC__)
+static void BM_stdlib_calloc_free_decay1(benchmark::State& state) {
+  mallopt(M_DECAY_TIME, 1);
+
+  CallocFree(state);
+
+  mallopt(M_DECAY_TIME, 0);
+}
+BIONIC_BENCHMARK_WITH_ARG(BM_stdlib_calloc_free_decay1, "AT_COMMON_SIZES");
+#endif
+
 static void MallocMultiple(benchmark::State& state, size_t nbytes, size_t numAllocs) {
   int pagesize = getpagesize();
   void* ptrs[numAllocs];