Merge "Optimize code that only uses PageMap call." am: 1e7b753c36 am: bdcd4f8e85
am: 7a7b844499
Change-Id: Ia88d5a89f1934ed2666bdd5e080a436a644002f8
diff --git a/include/meminfo/procmeminfo.h b/include/meminfo/procmeminfo.h
index 1fb4151..f782ec5 100644
--- a/include/meminfo/procmeminfo.h
+++ b/include/meminfo/procmeminfo.h
@@ -45,6 +45,9 @@
// vector.
const std::vector<Vma>& MapsWithPageIdle();
+ // Same as Maps() except, do not read the usage stats for each map.
+ const std::vector<Vma>& MapsWithoutUsageStats();
+
// Collect all 'vma' or 'maps' from /proc/<pid>/smaps and store them in 'maps_'. Returns a
// constant reference to the vma vector after the collection is done.
//
@@ -88,7 +91,7 @@
~ProcMemInfo() = default;
private:
- bool ReadMaps(bool get_wss, bool use_pageidle = false);
+ bool ReadMaps(bool get_wss, bool use_pageidle = false, bool get_usage_stats = true);
bool ReadVmaStats(int pagemap_fd, Vma& vma, bool get_wss, bool use_pageidle);
pid_t pid_;
diff --git a/libmeminfo_test.cpp b/libmeminfo_test.cpp
index 5451ca3..4c2be91 100644
--- a/libmeminfo_test.cpp
+++ b/libmeminfo_test.cpp
@@ -14,6 +14,7 @@
* limitations under the License.
*/
+#include <sys/mman.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
@@ -60,6 +61,103 @@
EXPECT_FALSE(maps.empty());
}
+TEST(ProcMemInfo, MapsUsageNotEmpty) {
+ ProcMemInfo proc_mem(pid);
+ const std::vector<Vma>& maps = proc_mem.Maps();
+ EXPECT_FALSE(maps.empty());
+ uint64_t total_pss = 0;
+ uint64_t total_rss = 0;
+ uint64_t total_uss = 0;
+ for (auto& map : maps) {
+ ASSERT_NE(0, map.usage.vss);
+ total_rss += map.usage.rss;
+ total_pss += map.usage.pss;
+ total_uss += map.usage.uss;
+ }
+
+ // Crude check that stats are actually being read.
+ EXPECT_NE(0, total_rss) << "RSS zero for all maps, that is not possible.";
+ EXPECT_NE(0, total_pss) << "PSS zero for all maps, that is not possible.";
+ EXPECT_NE(0, total_uss) << "USS zero for all maps, that is not possible.";
+}
+
+TEST(ProcMemInfo, MapsUsageEmpty) {
+ ProcMemInfo proc_mem(pid);
+ const std::vector<Vma>& maps = proc_mem.MapsWithoutUsageStats();
+ EXPECT_FALSE(maps.empty());
+ // Verify that all usage stats are zero in every map.
+ for (auto& map : maps) {
+ ASSERT_EQ(0, map.usage.vss);
+ ASSERT_EQ(0, map.usage.rss);
+ ASSERT_EQ(0, map.usage.pss);
+ ASSERT_EQ(0, map.usage.uss);
+ ASSERT_EQ(0, map.usage.swap);
+ ASSERT_EQ(0, map.usage.swap_pss);
+ ASSERT_EQ(0, map.usage.private_clean);
+ ASSERT_EQ(0, map.usage.private_dirty);
+ ASSERT_EQ(0, map.usage.shared_clean);
+ ASSERT_EQ(0, map.usage.shared_dirty);
+ }
+}
+
+TEST(ProcMemInfo, PageMapPresent) {
+ static constexpr size_t kNumPages = 20;
+ size_t pagesize = getpagesize();
+ void* ptr = mmap(nullptr, pagesize * (kNumPages + 2), PROT_READ | PROT_WRITE,
+ MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+ ASSERT_NE(MAP_FAILED, ptr);
+
+ // Unmap the first page and the last page so that we guarantee this
+ // map is in a map by itself.
+ ASSERT_EQ(0, munmap(ptr, pagesize));
+ uintptr_t addr = reinterpret_cast<uintptr_t>(ptr) + pagesize;
+ ASSERT_EQ(0, munmap(reinterpret_cast<void*>(addr + kNumPages * pagesize), pagesize));
+
+ ProcMemInfo proc_mem(getpid());
+ const std::vector<Vma>& maps = proc_mem.MapsWithoutUsageStats();
+ ASSERT_FALSE(maps.empty());
+
+ // Find the vma associated with our previously created map.
+ const Vma* test_vma = nullptr;
+ for (const Vma& vma : maps) {
+ if (vma.start == addr) {
+ test_vma = &vma;
+ break;
+ }
+ }
+ ASSERT_TRUE(test_vma != nullptr) << "Cannot find test map.";
+
+ // Verify that none of the pages are listed as present.
+ std::vector<uint64_t> pagemap;
+ ASSERT_TRUE(proc_mem.PageMap(*test_vma, &pagemap));
+ ASSERT_EQ(kNumPages, pagemap.size());
+ for (size_t i = 0; i < pagemap.size(); i++) {
+ EXPECT_FALSE(android::meminfo::page_present(pagemap[i]))
+ << "Page " << i << " is present and it should not be.";
+ }
+
+ // Make some of the pages present and verify that we see them
+ // as present.
+ uint8_t* data = reinterpret_cast<uint8_t*>(addr);
+ data[0] = 1;
+ data[pagesize * 5] = 1;
+ data[pagesize * 11] = 1;
+
+ ASSERT_TRUE(proc_mem.PageMap(*test_vma, &pagemap));
+ ASSERT_EQ(kNumPages, pagemap.size());
+ for (size_t i = 0; i < pagemap.size(); i++) {
+ if (i == 0 || i == 5 || i == 11) {
+ EXPECT_TRUE(android::meminfo::page_present(pagemap[i]))
+ << "Page " << i << " is not present and it should be.";
+ } else {
+ EXPECT_FALSE(android::meminfo::page_present(pagemap[i]))
+ << "Page " << i << " is present and it should not be.";
+ }
+ }
+
+ ASSERT_EQ(0, munmap(reinterpret_cast<void*>(addr), kNumPages * pagesize));
+}
+
TEST(ProcMemInfo, WssEmpty) {
// If we created the object for getting usage,
// the working set must be empty
diff --git a/procmeminfo.cpp b/procmeminfo.cpp
index a8b43c1..6f68ab4 100644
--- a/procmeminfo.cpp
+++ b/procmeminfo.cpp
@@ -130,6 +130,14 @@
return maps_;
}
+const std::vector<Vma>& ProcMemInfo::MapsWithoutUsageStats() {
+ if (maps_.empty() && !ReadMaps(get_wss_, false, false)) {
+ LOG(ERROR) << "Failed to read maps for Process " << pid_;
+ }
+
+ return maps_;
+}
+
const std::vector<Vma>& ProcMemInfo::Smaps(const std::string& path) {
if (!maps_.empty()) {
return maps_;
@@ -213,29 +221,30 @@
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) {
+ if (pagemap_fd == -1) {
PLOG(ERROR) << "Failed to open " << pagemap_file;
return false;
}
uint64_t nr_pages = (vma.end - vma.start) / getpagesize();
- pagemap->reserve(nr_pages);
+ pagemap->resize(nr_pages);
- uint64_t idx = vma.start / getpagesize();
- uint64_t last = idx + nr_pages;
- uint64_t val;
- for (; idx < last; idx++) {
- if (pread64(pagemap_fd, &val, sizeof(uint64_t), idx * sizeof(uint64_t)) < 0) {
- PLOG(ERROR) << "Failed to read page frames from page map for pid: " << pid_;
- return false;
- }
- pagemap->emplace_back(val);
+ size_t bytes_to_read = sizeof(uint64_t) * nr_pages;
+ off64_t start_addr = (vma.start / getpagesize()) * sizeof(uint64_t);
+ ssize_t bytes_read = pread64(pagemap_fd, pagemap->data(), bytes_to_read, start_addr);
+ if (bytes_read == -1) {
+ PLOG(ERROR) << "Failed to read page frames from page map for pid: " << pid_;
+ return false;
+ } else if (static_cast<size_t>(bytes_read) != bytes_to_read) {
+ LOG(ERROR) << "Failed to read page frames from page map for pid: " << pid_
+ << ": read bytes " << bytes_read << " expected bytes " << bytes_to_read;
+ return false;
}
return true;
}
-bool ProcMemInfo::ReadMaps(bool get_wss, bool use_pageidle) {
+bool ProcMemInfo::ReadMaps(bool get_wss, bool use_pageidle, bool get_usage_stats) {
// Each object reads /proc/<pid>/maps only once. This is done to make sure programs that are
// running for the lifetime of the system can recycle the objects and don't have to
// unnecessarily retain and update this object in memory (which can get significantly large).
@@ -256,6 +265,10 @@
return false;
}
+ if (!get_usage_stats) {
+ return true;
+ }
+
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)));
