libmeminfo: Add libmeminfo to gather global and per-process memory stats
The library is expected to be a unified place for all components to read
both global and per-process memory accounting form kernel including
getting the working set. This change adds the PageInfo, MemInfo and
ProcMemInfo classes and verifies the implementation against libpagemap
for correctness.
Adds a procmem2 tool show the usage.
TODO: Plumbing in os_debug, add vmastats, zoneinfo etc parsing.
Test: libmeminfo_test 1
Test: procmem2 1
Test: procmem2 -h -W 1
Test: procmem2 -h -w 1
Test: libmeminfo_benchmark
Bug: 111694435
Bug: 114325007
Change-Id: I280440b1dc26a498170686d10fcf63f953a0dcbd
Signed-off-by: Sandeep Patil <sspatil@google.com>
diff --git a/libmeminfo/procmeminfo.cpp b/libmeminfo/procmeminfo.cpp
new file mode 100644
index 0000000..fe91d25
--- /dev/null
+++ b/libmeminfo/procmeminfo.cpp
@@ -0,0 +1,218 @@
+/*
+ * Copyright (C) 2018 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 <errno.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <linux/kernel-page-flags.h>
+#include <stdio.h>
+#include <unistd.h>
+
+#include <fstream>
+#include <iostream>
+#include <memory>
+#include <string>
+#include <utility>
+
+#include <android-base/file.h>
+#include <android-base/logging.h>
+#include <android-base/stringprintf.h>
+#include <android-base/unique_fd.h>
+#include <procinfo/process_map.h>
+
+#include "meminfo_private.h"
+
+namespace android {
+namespace meminfo {
+
+static void add_mem_usage(MemUsage* to, const MemUsage& from) {
+ to->vss += from.vss;
+ to->rss += from.rss;
+ to->pss += from.pss;
+ to->uss += from.uss;
+
+ to->private_clean += from.private_clean;
+ to->private_dirty += from.private_dirty;
+
+ to->shared_clean += from.shared_clean;
+ to->shared_dirty += from.shared_dirty;
+}
+
+ProcMemInfo::ProcMemInfo(pid_t pid, bool get_wss) : pid_(pid), get_wss_(get_wss) {
+ if (!ReadMaps(get_wss_)) {
+ LOG(ERROR) << "Failed to read maps for Process " << pid_;
+ }
+}
+
+const std::vector<Vma>& ProcMemInfo::Maps() {
+ return maps_;
+}
+
+const MemUsage& ProcMemInfo::Usage() {
+ if (get_wss_) {
+ LOG(WARNING) << "Trying to read memory usage from working set object";
+ }
+ return usage_;
+}
+
+const MemUsage& ProcMemInfo::Wss() {
+ if (!get_wss_) {
+ LOG(WARNING) << "Trying to read working set when there is none";
+ }
+
+ return wss_;
+}
+
+bool ProcMemInfo::WssReset() {
+ if (!get_wss_) {
+ LOG(ERROR) << "Trying to reset working set from a memory usage counting object";
+ return false;
+ }
+
+ std::string clear_refs_path = ::android::base::StringPrintf("/proc/%d/clear_refs", pid_);
+ if (!::android::base::WriteStringToFile("1\n", clear_refs_path)) {
+ PLOG(ERROR) << "Failed to write to " << clear_refs_path;
+ return false;
+ }
+
+ wss_.clear();
+ return true;
+}
+
+bool ProcMemInfo::ReadMaps(bool get_wss) {
+ // parse and read /proc/<pid>/maps
+ std::string maps_file = ::android::base::StringPrintf("/proc/%d/maps", pid_);
+ if (!::android::procinfo::ReadMapFile(
+ maps_file, [&](uint64_t start, uint64_t end, uint16_t flags, uint64_t pgoff,
+ const char* name) {
+ maps_.emplace_back(Vma(start, end, pgoff, flags, name));
+ })) {
+ LOG(ERROR) << "Failed to parse " << maps_file;
+ maps_.clear();
+ return false;
+ }
+
+ std::string pagemap_file = ::android::base::StringPrintf("/proc/%d/pagemap", pid_);
+ ::android::base::unique_fd pagemap_fd(
+ TEMP_FAILURE_RETRY(open(pagemap_file.c_str(), O_RDONLY | O_CLOEXEC)));
+ if (pagemap_fd < 0) {
+ PLOG(ERROR) << "Failed to open " << pagemap_file;
+ return false;
+ }
+
+ for (auto& vma : maps_) {
+ if (!ReadVmaStats(pagemap_fd.get(), vma, get_wss)) {
+ LOG(ERROR) << "Failed to read page map for vma " << vma.name << "[" << vma.start
+ << "-" << vma.end << "]";
+ maps_.clear();
+ return false;
+ }
+ if (get_wss) {
+ add_mem_usage(&wss_, vma.wss);
+ } else {
+ add_mem_usage(&usage_, vma.usage);
+ }
+ }
+
+ return true;
+}
+
+bool ProcMemInfo::ReadVmaStats(int pagemap_fd, Vma& vma, bool get_wss) {
+ PageAcct& pinfo = PageAcct::Instance();
+ uint64_t pagesz = getpagesize();
+ uint64_t num_pages = (vma.end - vma.start) / pagesz;
+
+ std::unique_ptr<uint64_t[]> pg_frames(new uint64_t[num_pages]);
+ uint64_t first = vma.start / pagesz;
+ if (pread64(pagemap_fd, pg_frames.get(), num_pages * sizeof(uint64_t),
+ first * sizeof(uint64_t)) < 0) {
+ PLOG(ERROR) << "Failed to read page frames from page map for pid: " << pid_;
+ return false;
+ }
+
+ std::unique_ptr<uint64_t[]> pg_flags(new uint64_t[num_pages]);
+ std::unique_ptr<uint64_t[]> pg_counts(new uint64_t[num_pages]);
+ for (uint64_t i = 0; i < num_pages; ++i) {
+ if (!get_wss) {
+ vma.usage.vss += pagesz;
+ }
+ uint64_t p = pg_frames[i];
+ if (!PAGE_PRESENT(p) && !PAGE_SWAPPED(p)) continue;
+
+ if (PAGE_SWAPPED(p)) {
+ // TODO: do what's needed for swapped pages
+ continue;
+ }
+
+ uint64_t page_frame = PAGE_PFN(p);
+ if (!pinfo.PageFlags(page_frame, &pg_flags[i])) {
+ LOG(ERROR) << "Failed to get page flags for " << page_frame << " in process " << pid_;
+ return false;
+ }
+
+ if (!pinfo.PageMapCount(page_frame, &pg_counts[i])) {
+ LOG(ERROR) << "Failed to get page count for " << page_frame << " in process " << pid_;
+ return false;
+ }
+
+ // Page was unmapped between the presence check at the beginning of the loop and here.
+ if (pg_counts[i] == 0) {
+ pg_frames[i] = 0;
+ pg_flags[i] = 0;
+ continue;
+ }
+
+ bool is_dirty = !!(pg_flags[i] & (1 << KPF_DIRTY));
+ bool is_private = (pg_counts[i] == 1);
+ // Working set
+ if (get_wss) {
+ bool is_referenced = !!(pg_flags[i] & (1 << KPF_REFERENCED));
+ if (!is_referenced) {
+ continue;
+ }
+ // This effectively makes vss = rss for the working set is requested.
+ // The libpagemap implementation returns vss > rss for
+ // working set, which doesn't make sense.
+ vma.wss.vss += pagesz;
+ vma.wss.rss += pagesz;
+ vma.wss.uss += is_private ? pagesz : 0;
+ vma.wss.pss += pagesz / pg_counts[i];
+ if (is_private) {
+ vma.wss.private_dirty += is_dirty ? pagesz : 0;
+ vma.wss.private_clean += is_dirty ? 0 : pagesz;
+ } else {
+ vma.wss.shared_dirty += is_dirty ? pagesz : 0;
+ vma.wss.shared_clean += is_dirty ? 0 : pagesz;
+ }
+ } else {
+ vma.usage.rss += pagesz;
+ vma.usage.uss += is_private ? pagesz : 0;
+ vma.usage.pss += pagesz / pg_counts[i];
+ if (is_private) {
+ vma.usage.private_dirty += is_dirty ? pagesz : 0;
+ vma.usage.private_clean += is_dirty ? 0 : pagesz;
+ } else {
+ vma.usage.shared_dirty += is_dirty ? pagesz : 0;
+ vma.usage.shared_clean += is_dirty ? 0 : pagesz;
+ }
+ }
+ }
+
+ return true;
+}
+
+} // namespace meminfo
+} // namespace android