Move init bootcharting onto its own thread.
This reduces the overhead when bootcharting is on (obviously), but also
removes the "do we need to do anything for bootcharting?" check in cases
where we're not bootcharting.
Bug: http://b/23478578
Bug: http://b/33450491
Test: rebooted with bootcharting on/off
Change-Id: Id8746b5023b17d7615679eba0bcd02aee048ef1a
diff --git a/init/bootchart.cpp b/init/bootchart.cpp
index 7a8a3d5..4a9c32e 100644
--- a/init/bootchart.cpp
+++ b/init/bootchart.cpp
@@ -15,7 +15,7 @@
*/
#include "bootchart.h"
-#include "log.h"
+
#include "property_service.h"
#include <dirent.h>
@@ -29,197 +29,170 @@
#include <time.h>
#include <unistd.h>
+#include <chrono>
+#include <condition_variable>
#include <memory>
+#include <mutex>
#include <string>
+#include <thread>
#include <vector>
#include <android-base/file.h>
+#include <android-base/logging.h>
#include <android-base/stringprintf.h>
using android::base::StringPrintf;
+using namespace std::chrono_literals;
-static constexpr const char* LOG_STAT = "/data/bootchart/proc_stat.log";
-static constexpr const char* LOG_PROC = "/data/bootchart/proc_ps.log";
-static constexpr const char* LOG_DISK = "/data/bootchart/proc_diskstats.log";
-static constexpr const char* LOG_HEADER = "/data/bootchart/header";
+static std::thread* g_bootcharting_thread;
-// Polling period in ms.
-static constexpr int BOOTCHART_POLLING_MS = 200;
-
-static long long g_last_bootchart_time;
-
-static bool g_bootcharting = false;
-
-static FILE* g_stat_log;
-static FILE* g_proc_log;
-static FILE* g_disk_log;
+static std::mutex g_bootcharting_finished_mutex;
+static std::condition_variable g_bootcharting_finished_cv;
+static bool g_bootcharting_finished;
static long long get_uptime_jiffies() {
- std::string uptime;
- if (!android::base::ReadFileToString("/proc/uptime", &uptime)) {
- return 0;
- }
- return 100LL * strtod(uptime.c_str(), NULL);
+ std::string uptime;
+ if (!android::base::ReadFileToString("/proc/uptime", &uptime)) return 0;
+ return 100LL * strtod(uptime.c_str(), NULL);
+}
+
+static std::unique_ptr<FILE, decltype(&fclose)> fopen_unique(const char* filename,
+ const char* mode) {
+ std::unique_ptr<FILE, decltype(&fclose)> result(fopen(filename, mode), fclose);
+ if (!result) PLOG(ERROR) << "bootchart: failed to open " << filename;
+ return result;
}
static void log_header() {
- char date[32];
- time_t now_t = time(NULL);
- struct tm now = *localtime(&now_t);
- strftime(date, sizeof(date), "%F %T", &now);
+ char date[32];
+ time_t now_t = time(NULL);
+ struct tm now = *localtime(&now_t);
+ strftime(date, sizeof(date), "%F %T", &now);
- utsname uts;
- if (uname(&uts) == -1) {
- return;
- }
+ utsname uts;
+ if (uname(&uts) == -1) return;
- std::string fingerprint = property_get("ro.build.fingerprint");
- if (fingerprint.empty()) {
- return;
- }
+ std::string fingerprint = property_get("ro.build.fingerprint");
+ if (fingerprint.empty()) return;
- std::string kernel_cmdline;
- android::base::ReadFileToString("/proc/cmdline", &kernel_cmdline);
+ std::string kernel_cmdline;
+ android::base::ReadFileToString("/proc/cmdline", &kernel_cmdline);
- FILE* out = fopen(LOG_HEADER, "we");
- if (out == NULL) {
- return;
- }
- fprintf(out, "version = Android init 0.8\n");
- fprintf(out, "title = Boot chart for Android (%s)\n", date);
- fprintf(out, "system.uname = %s %s %s %s\n", uts.sysname, uts.release, uts.version, uts.machine);
- fprintf(out, "system.release = %s\n", fingerprint.c_str());
- // TODO: use /proc/cpuinfo "model name" line for x86, "Processor" line for arm.
- fprintf(out, "system.cpu = %s\n", uts.machine);
- fprintf(out, "system.kernel.options = %s\n", kernel_cmdline.c_str());
- fclose(out);
+ auto fp = fopen_unique("/data/bootchart/header", "we");
+ if (!fp) return;
+ fprintf(&*fp, "version = Android init 0.8\n");
+ fprintf(&*fp, "title = Boot chart for Android (%s)\n", date);
+ fprintf(&*fp, "system.uname = %s %s %s %s\n", uts.sysname, uts.release, uts.version, uts.machine);
+ fprintf(&*fp, "system.release = %s\n", fingerprint.c_str());
+ // TODO: use /proc/cpuinfo "model name" line for x86, "Processor" line for arm.
+ fprintf(&*fp, "system.cpu = %s\n", uts.machine);
+ fprintf(&*fp, "system.kernel.options = %s\n", kernel_cmdline.c_str());
}
static void log_uptime(FILE* log) {
- fprintf(log, "%lld\n", get_uptime_jiffies());
+ fprintf(log, "%lld\n", get_uptime_jiffies());
}
static void log_file(FILE* log, const char* procfile) {
- log_uptime(log);
+ log_uptime(log);
- std::string content;
- if (android::base::ReadFileToString(procfile, &content)) {
- fprintf(log, "%s\n", content.c_str());
- }
+ std::string content;
+ if (android::base::ReadFileToString(procfile, &content)) {
+ fprintf(log, "%s\n", content.c_str());
+ }
}
-static void log_processes() {
- log_uptime(g_proc_log);
+static void log_processes(FILE* log) {
+ log_uptime(log);
- std::unique_ptr<DIR, int(*)(DIR*)> dir(opendir("/proc"), closedir);
- struct dirent* entry;
- while ((entry = readdir(dir.get())) != NULL) {
- // Only match numeric values.
- int pid = atoi(entry->d_name);
- if (pid == 0) continue;
+ std::unique_ptr<DIR, int(*)(DIR*)> dir(opendir("/proc"), closedir);
+ struct dirent* entry;
+ while ((entry = readdir(dir.get())) != NULL) {
+ // Only match numeric values.
+ int pid = atoi(entry->d_name);
+ if (pid == 0) continue;
- // /proc/<pid>/stat only has truncated task names, so get the full
- // name from /proc/<pid>/cmdline.
- std::string cmdline;
- android::base::ReadFileToString(StringPrintf("/proc/%d/cmdline", pid), &cmdline);
- const char* full_name = cmdline.c_str(); // So we stop at the first NUL.
+ // /proc/<pid>/stat only has truncated task names, so get the full
+ // name from /proc/<pid>/cmdline.
+ std::string cmdline;
+ android::base::ReadFileToString(StringPrintf("/proc/%d/cmdline", pid), &cmdline);
+ const char* full_name = cmdline.c_str(); // So we stop at the first NUL.
- // Read process stat line.
- std::string stat;
- if (android::base::ReadFileToString(StringPrintf("/proc/%d/stat", pid), &stat)) {
- if (!cmdline.empty()) {
- // Substitute the process name with its real name.
- size_t open = stat.find('(');
- size_t close = stat.find_last_of(')');
- if (open != std::string::npos && close != std::string::npos) {
- stat.replace(open + 1, close - open - 1, full_name);
- }
- }
- fputs(stat.c_str(), g_proc_log);
+ // Read process stat line.
+ std::string stat;
+ if (android::base::ReadFileToString(StringPrintf("/proc/%d/stat", pid), &stat)) {
+ if (!cmdline.empty()) {
+ // Substitute the process name with its real name.
+ size_t open = stat.find('(');
+ size_t close = stat.find_last_of(')');
+ if (open != std::string::npos && close != std::string::npos) {
+ stat.replace(open + 1, close - open - 1, full_name);
}
+ }
+ fputs(stat.c_str(), log);
+ }
+ }
+
+ fputc('\n', log);
+}
+
+static void bootchart_thread_main() {
+ LOG(INFO) << "Bootcharting started";
+
+ // Open log files.
+ auto stat_log = fopen_unique("/data/bootchart/proc_stat.log", "we");
+ if (!stat_log) return;
+ auto proc_log = fopen_unique("/data/bootchart/proc_ps.log", "we");
+ if (!proc_log) return;
+ auto disk_log = fopen_unique("/data/bootchart/proc_diskstats.log", "we");
+ if (!disk_log) return;
+
+ log_header();
+
+ while (true) {
+ {
+ std::unique_lock<std::mutex> lock(g_bootcharting_finished_mutex);
+ g_bootcharting_finished_cv.wait_for(lock, 200ms);
+ if (g_bootcharting_finished) break;
}
- fputc('\n', g_proc_log);
+ log_file(&*stat_log, "/proc/stat");
+ log_file(&*disk_log, "/proc/diskstats");
+ log_processes(&*proc_log);
+ }
+
+ LOG(INFO) << "Bootcharting finished";
}
static int do_bootchart_start() {
- // We don't care about the content, but we do care that /data/bootchart/enabled actually exists.
- std::string start;
- if (!android::base::ReadFileToString("/data/bootchart/enabled", &start)) {
- LOG(VERBOSE) << "Not bootcharting";
- return 0;
- }
-
- // Open log files.
- std::unique_ptr<FILE, decltype(&fclose)> stat_log(fopen(LOG_STAT, "we"), fclose);
- if (!stat_log) {
- PLOG(ERROR) << "Bootcharting couldn't open " << LOG_STAT;
- return -1;
- }
- std::unique_ptr<FILE, decltype(&fclose)> proc_log(fopen(LOG_PROC, "we"), fclose);
- if (!proc_log) {
- PLOG(ERROR) << "Bootcharting couldn't open " << LOG_PROC;
- return -1;
- }
- std::unique_ptr<FILE, decltype(&fclose)> disk_log(fopen(LOG_DISK, "we"), fclose);
- if (!disk_log) {
- PLOG(ERROR) << "Bootcharting couldn't open " << LOG_DISK;
- return -1;
- }
-
- LOG(INFO) << "Bootcharting started";
- g_stat_log = stat_log.release();
- g_proc_log = proc_log.release();
- g_disk_log = disk_log.release();
- g_bootcharting = true;
- log_header();
-
+ // We don't care about the content, but we do care that /data/bootchart/enabled actually exists.
+ std::string start;
+ if (!android::base::ReadFileToString("/data/bootchart/enabled", &start)) {
+ LOG(VERBOSE) << "Not bootcharting";
return 0;
-}
+ }
-static void do_bootchart_step() {
- log_file(g_stat_log, "/proc/stat");
- log_file(g_disk_log, "/proc/diskstats");
- log_processes();
+ g_bootcharting_thread = new std::thread(bootchart_thread_main);
+ return 0;
}
static int do_bootchart_stop() {
- if (!g_bootcharting) return 0;
+ if (!g_bootcharting_thread) return 0;
- LOG(INFO) << "Bootcharting finished";
- g_bootcharting = false;
- fclose(g_stat_log);
- fclose(g_disk_log);
- fclose(g_proc_log);
- return 0;
+ // Tell the worker thread it's time to quit.
+ {
+ std::lock_guard<std::mutex> lock(g_bootcharting_finished_mutex);
+ g_bootcharting_finished = true;
+ g_bootcharting_finished_cv.notify_one();
+ }
+
+ g_bootcharting_thread->join();
+ delete g_bootcharting_thread;
+ g_bootcharting_thread = nullptr;
+ return 0;
}
int do_bootchart(const std::vector<std::string>& args) {
- if (args[1] == "start") return do_bootchart_start();
- return do_bootchart_stop();
-}
-
-void bootchart_sample(int* timeout) {
- // Do we have any more bootcharting to do?
- if (!g_bootcharting) return;
-
- long long current_time = 10LL * get_uptime_jiffies();
- int elapsed_time = current_time - g_last_bootchart_time;
-
- if (elapsed_time >= BOOTCHART_POLLING_MS) {
- while (elapsed_time >= BOOTCHART_POLLING_MS) {
- elapsed_time -= BOOTCHART_POLLING_MS;
- }
-
- g_last_bootchart_time = current_time;
- do_bootchart_step();
- }
-
- // Schedule another?
- if (g_bootcharting) {
- int remaining_time = BOOTCHART_POLLING_MS - elapsed_time;
- if (*timeout < 0 || *timeout > remaining_time) {
- *timeout = remaining_time;
- }
- }
+ if (args[1] == "start") return do_bootchart_start();
+ return do_bootchart_stop();
}