libmeminfo: Add support to read zram memory consumption
Bug: 114325007
Bug: 111694435
Test: libmeminfo_test 1 --gtest_filter=SysMemInfoParse.TestZramTotal
Benchmark: libmeminfo_benchmark --benchmark_filter=BM_.*ZramTotal
Benchmark Result on Blueline:
-----------------------------------------------------------
Benchmark Time CPU Iterations
-----------------------------------------------------------
BM_OldReadZramTotal 3857 ns 3839 ns 134096
BM_NewReadZramTotal 4461 ns 4440 ns 157341
Change-Id: I5220fa17b101981ef859179960fe78fe68e84852
Signed-off-by: Sandeep Patil <[email protected]>
diff --git a/sysmeminfo.cpp b/sysmeminfo.cpp
index 82605b6..7e56238 100644
--- a/sysmeminfo.cpp
+++ b/sysmeminfo.cpp
@@ -17,10 +17,12 @@
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
+#include <inttypes.h>
#include <stdlib.h>
#include <unistd.h>
#include <cctype>
+#include <cstdio>
#include <fstream>
#include <string>
#include <utility>
@@ -29,7 +31,9 @@
#include <android-base/file.h>
#include <android-base/logging.h>
#include <android-base/parseint.h>
+#include <android-base/stringprintf.h>
#include <android-base/strings.h>
+#include <android-base/unique_fd.h>
#include "meminfo_private.h"
@@ -37,11 +41,11 @@
namespace meminfo {
const std::vector<std::string> SysMemInfo::kDefaultSysMemInfoTags = {
- SysMemInfo::kMemTotal, SysMemInfo::kMemFree, SysMemInfo::kMemBuffers,
- SysMemInfo::kMemCached, SysMemInfo::kMemShmem, SysMemInfo::kMemSlab,
- SysMemInfo::kMemSReclaim, SysMemInfo::kMemSUnreclaim, SysMemInfo::kMemSwapTotal,
- SysMemInfo::kMemSwapFree, SysMemInfo::kMemZram, SysMemInfo::kMemMapped,
- SysMemInfo::kMemVmallocUsed, SysMemInfo::kMemPageTables, SysMemInfo::kMemKernelStack,
+ SysMemInfo::kMemTotal, SysMemInfo::kMemFree, SysMemInfo::kMemBuffers,
+ SysMemInfo::kMemCached, SysMemInfo::kMemShmem, SysMemInfo::kMemSlab,
+ SysMemInfo::kMemSReclaim, SysMemInfo::kMemSUnreclaim, SysMemInfo::kMemSwapTotal,
+ SysMemInfo::kMemSwapFree, SysMemInfo::kMemMapped, SysMemInfo::kMemVmallocUsed,
+ SysMemInfo::kMemPageTables, SysMemInfo::kMemKernelStack,
};
bool SysMemInfo::ReadMemInfo(const std::string& path) {
@@ -129,5 +133,68 @@
}
#endif
+uint64_t SysMemInfo::mem_zram_kb(const std::string& zram_dev) {
+ uint64_t mem_zram_total = 0;
+ if (!zram_dev.empty()) {
+ if (!MemZramDevice(zram_dev, &mem_zram_total)) {
+ return 0;
+ }
+ return mem_zram_total / 1024;
+ }
+
+ constexpr uint32_t kMaxZramDevices = 256;
+ for (uint32_t i = 0; i < kMaxZramDevices; i++) {
+ std::string zram_dev = ::android::base::StringPrintf("/sys/block/zram%u/", i);
+ if (access(zram_dev.c_str(), F_OK)) {
+ // We assume zram devices appear in range 0-255 and appear always in sequence
+ // under /sys/block. So, stop looking for them once we find one is missing.
+ break;
+ }
+
+ uint64_t mem_zram_dev;
+ if (!MemZramDevice(zram_dev, &mem_zram_dev)) {
+ return 0;
+ }
+
+ mem_zram_total += mem_zram_dev;
+ }
+
+ return mem_zram_total / 1024;
+}
+
+bool SysMemInfo::MemZramDevice(const std::string& zram_dev, uint64_t* mem_zram_dev) {
+ std::string content;
+ if (android::base::ReadFileToString(zram_dev + "mm_stat", &content)) {
+ std::vector<std::string> values = ::android::base::Split(content, " ");
+ if (values.size() < 3) {
+ LOG(ERROR) << "Malformed mm_stat file for zram dev: " << zram_dev
+ << " content: " << content;
+ return false;
+ }
+
+ if (!::android::base::ParseUint(values[2], mem_zram_dev)) {
+ LOG(ERROR) << "Malformed mm_stat file for zram dev: " << zram_dev
+ << " value: " << values[2];
+ return false;
+ }
+
+ return true;
+ }
+
+ if (::android::base::ReadFileToString(zram_dev + "mem_used_total", &content)) {
+ *mem_zram_dev = strtoull(content.c_str(), NULL, 10);
+ if (*mem_zram_dev == ULLONG_MAX) {
+ PLOG(ERROR) << "Malformed mem_used_total file for zram dev: " << zram_dev
+ << " content: " << content;
+ return false;
+ }
+
+ return true;
+ }
+
+ LOG(ERROR) << "Can't find memory status under: " << zram_dev;
+ return false;
+}
+
} // namespace meminfo
} // namespace android
