Optimize Memory::ReadString
This function is responsible for majority of CPU time in prefetto.
Reduce the number of memory reads (don't read strings byte-by-byte).
Update all calls of ReadString to include the third parameter to have
a max read.
Add an Elf creation benchmark since this function is on the elf
creation path.
Test: libunwindstack_unit_test
Change-Id: Ia36e1f1a5ba76c9e9f13c43fb9e3691dde7897f2
diff --git a/libunwindstack/benchmarks/Utils.cpp b/libunwindstack/benchmarks/Utils.cpp
new file mode 100644
index 0000000..c92f109
--- /dev/null
+++ b/libunwindstack/benchmarks/Utils.cpp
@@ -0,0 +1,62 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <err.h>
+#include <stdint.h>
+
+#include <string>
+#include <vector>
+
+#include <android-base/file.h>
+#include <android-base/strings.h>
+#include <benchmark/benchmark.h>
+
+#include <unwindstack/Elf.h>
+#include <unwindstack/Memory.h>
+
+std::string GetElfFile() {
+ return android::base::GetExecutableDirectory() + "/benchmarks/files/libart_arm.so";
+}
+
+std::string GetSymbolSortedElfFile() {
+ return android::base::GetExecutableDirectory() + "/benchmarks/files/boot_arm.oat";
+}
+
+std::string GetCompressedElfFile() {
+ // Both are the same right now.
+ return GetSymbolSortedElfFile();
+}
+
+#if defined(__BIONIC__)
+
+#include <meminfo/procmeminfo.h>
+#include <procinfo/process_map.h>
+
+void GatherRss(uint64_t* rss_bytes) {
+ android::meminfo::ProcMemInfo proc_mem(getpid());
+ const std::vector<android::meminfo::Vma>& maps = proc_mem.MapsWithoutUsageStats();
+ for (auto& vma : maps) {
+ if (vma.name == "[anon:libc_malloc]" || android::base::StartsWith(vma.name, "[anon:scudo:") ||
+ android::base::StartsWith(vma.name, "[anon:GWP-ASan")) {
+ android::meminfo::Vma update_vma(vma);
+ if (!proc_mem.FillInVmaStats(update_vma)) {
+ err(1, "FillInVmaStats failed\n");
+ }
+ *rss_bytes += update_vma.usage.rss;
+ }
+ }
+}
+#endif