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Commit a92616ec authored by Treehugger Robot's avatar Treehugger Robot Committed by Gerrit Code Review
Browse files

Merge "Update atrace to work with tracefs, not debugfs"

parents 4d741ebe 2cd93cc4

cmds/atrace/atrace.cpp

+103 −73
Original line number Diff line number Diff line
@@ -112,81 +112,81 @@ static const TracingCategory k_categories[] = { 
    { "adb",        "ADB",              ATRACE_TAG_ADB, { } },

    { k_coreServiceCategory, "Core services", 0, { } },

    { "sched",      "CPU Scheduling",   0, {

        { REQ,      "/sys/kernel/debug/tracing/events/sched/sched_switch/enable" },

        { REQ,      "/sys/kernel/debug/tracing/events/sched/sched_wakeup/enable" },

        { OPT,      "/sys/kernel/debug/tracing/events/sched/sched_blocked_reason/enable" },

        { OPT,      "/sys/kernel/debug/tracing/events/sched/sched_cpu_hotplug/enable" },

        { REQ,      "events/sched/sched_switch/enable" },

        { REQ,      "events/sched/sched_wakeup/enable" },

        { OPT,      "events/sched/sched_blocked_reason/enable" },

        { OPT,      "events/sched/sched_cpu_hotplug/enable" },

    } },

    { "irq",        "IRQ Events",   0, {

        { REQ,      "/sys/kernel/debug/tracing/events/irq/enable" },

        { OPT,      "/sys/kernel/debug/tracing/events/ipi/enable" },

        { REQ,      "events/irq/enable" },

        { OPT,      "events/ipi/enable" },

    } },

    { "i2c",        "I2C Events",   0, {

        { REQ,      "/sys/kernel/debug/tracing/events/i2c/enable" },

        { REQ,      "/sys/kernel/debug/tracing/events/i2c/i2c_read/enable" },

        { REQ,      "/sys/kernel/debug/tracing/events/i2c/i2c_write/enable" },

        { REQ,      "/sys/kernel/debug/tracing/events/i2c/i2c_result/enable" },

        { REQ,      "/sys/kernel/debug/tracing/events/i2c/i2c_reply/enable" },

        { OPT,      "/sys/kernel/debug/tracing/events/i2c/smbus_read/enable" },

        { OPT,      "/sys/kernel/debug/tracing/events/i2c/smbus_write/enable" },

        { OPT,      "/sys/kernel/debug/tracing/events/i2c/smbus_result/enable" },

        { OPT,      "/sys/kernel/debug/tracing/events/i2c/smbus_reply/enable" },

        { REQ,      "events/i2c/enable" },

        { REQ,      "events/i2c/i2c_read/enable" },

        { REQ,      "events/i2c/i2c_write/enable" },

        { REQ,      "events/i2c/i2c_result/enable" },

        { REQ,      "events/i2c/i2c_reply/enable" },

        { OPT,      "events/i2c/smbus_read/enable" },

        { OPT,      "events/i2c/smbus_write/enable" },

        { OPT,      "events/i2c/smbus_result/enable" },

        { OPT,      "events/i2c/smbus_reply/enable" },

    } },

    { "freq",       "CPU Frequency",    0, {

        { REQ,      "/sys/kernel/debug/tracing/events/power/cpu_frequency/enable" },

        { OPT,      "/sys/kernel/debug/tracing/events/power/clock_set_rate/enable" },

        { OPT,      "/sys/kernel/debug/tracing/events/power/cpu_frequency_limits/enable" },

        { REQ,      "events/power/cpu_frequency/enable" },

        { OPT,      "events/power/clock_set_rate/enable" },

        { OPT,      "events/power/cpu_frequency_limits/enable" },

    } },

    { "membus",     "Memory Bus Utilization", 0, {

        { REQ,      "/sys/kernel/debug/tracing/events/memory_bus/enable" },

        { REQ,      "events/memory_bus/enable" },

    } },

    { "idle",       "CPU Idle",         0, {

        { REQ,      "/sys/kernel/debug/tracing/events/power/cpu_idle/enable" },

        { REQ,      "events/power/cpu_idle/enable" },

    } },

    { "disk",       "Disk I/O",         0, {

        { OPT,      "/sys/kernel/debug/tracing/events/f2fs/f2fs_sync_file_enter/enable" },

        { OPT,      "/sys/kernel/debug/tracing/events/f2fs/f2fs_sync_file_exit/enable" },

        { OPT,      "/sys/kernel/debug/tracing/events/f2fs/f2fs_write_begin/enable" },

        { OPT,      "/sys/kernel/debug/tracing/events/f2fs/f2fs_write_end/enable" },

        { OPT,      "/sys/kernel/debug/tracing/events/ext4/ext4_da_write_begin/enable" },

        { OPT,      "/sys/kernel/debug/tracing/events/ext4/ext4_da_write_end/enable" },

        { OPT,      "/sys/kernel/debug/tracing/events/ext4/ext4_sync_file_enter/enable" },

        { OPT,      "/sys/kernel/debug/tracing/events/ext4/ext4_sync_file_exit/enable" },

        { REQ,      "/sys/kernel/debug/tracing/events/block/block_rq_issue/enable" },

        { REQ,      "/sys/kernel/debug/tracing/events/block/block_rq_complete/enable" },

        { OPT,      "events/f2fs/f2fs_sync_file_enter/enable" },

        { OPT,      "events/f2fs/f2fs_sync_file_exit/enable" },

        { OPT,      "events/f2fs/f2fs_write_begin/enable" },

        { OPT,      "events/f2fs/f2fs_write_end/enable" },

        { OPT,      "events/ext4/ext4_da_write_begin/enable" },

        { OPT,      "events/ext4/ext4_da_write_end/enable" },

        { OPT,      "events/ext4/ext4_sync_file_enter/enable" },

        { OPT,      "events/ext4/ext4_sync_file_exit/enable" },

        { REQ,      "events/block/block_rq_issue/enable" },

        { REQ,      "events/block/block_rq_complete/enable" },

    } },

    { "mmc",        "eMMC commands",    0, {

        { REQ,      "/sys/kernel/debug/tracing/events/mmc/enable" },

        { REQ,      "events/mmc/enable" },

    } },

    { "load",       "CPU Load",         0, {

        { REQ,      "/sys/kernel/debug/tracing/events/cpufreq_interactive/enable" },

        { REQ,      "events/cpufreq_interactive/enable" },

    } },

    { "sync",       "Synchronization",  0, {

        { REQ,      "/sys/kernel/debug/tracing/events/sync/enable" },

        { REQ,      "events/sync/enable" },

    } },

    { "workq",      "Kernel Workqueues", 0, {

        { REQ,      "/sys/kernel/debug/tracing/events/workqueue/enable" },

        { REQ,      "events/workqueue/enable" },

    } },

    { "memreclaim", "Kernel Memory Reclaim", 0, {

        { REQ,      "/sys/kernel/debug/tracing/events/vmscan/mm_vmscan_direct_reclaim_begin/enable" },

        { REQ,      "/sys/kernel/debug/tracing/events/vmscan/mm_vmscan_direct_reclaim_end/enable" },

        { REQ,      "/sys/kernel/debug/tracing/events/vmscan/mm_vmscan_kswapd_wake/enable" },

        { REQ,      "/sys/kernel/debug/tracing/events/vmscan/mm_vmscan_kswapd_sleep/enable" },

        { REQ,      "events/vmscan/mm_vmscan_direct_reclaim_begin/enable" },

        { REQ,      "events/vmscan/mm_vmscan_direct_reclaim_end/enable" },

        { REQ,      "events/vmscan/mm_vmscan_kswapd_wake/enable" },

        { REQ,      "events/vmscan/mm_vmscan_kswapd_sleep/enable" },

    } },

    { "regulators",  "Voltage and Current Regulators", 0, {

        { REQ,      "/sys/kernel/debug/tracing/events/regulator/enable" },

        { REQ,      "events/regulator/enable" },

    } },

    { "binder_driver", "Binder Kernel driver", 0, {

        { REQ,      "/sys/kernel/debug/tracing/events/binder/binder_transaction/enable" },

        { REQ,      "/sys/kernel/debug/tracing/events/binder/binder_transaction_received/enable" },

        { REQ,      "events/binder/binder_transaction/enable" },

        { REQ,      "events/binder/binder_transaction_received/enable" },

    } },

    { "binder_lock", "Binder global lock trace", 0, {

        { REQ,      "/sys/kernel/debug/tracing/events/binder/binder_lock/enable" },

        { REQ,      "/sys/kernel/debug/tracing/events/binder/binder_locked/enable" },

        { REQ,      "/sys/kernel/debug/tracing/events/binder/binder_unlock/enable" },

        { REQ,      "events/binder/binder_lock/enable" },

        { REQ,      "events/binder/binder_locked/enable" },

        { REQ,      "events/binder/binder_unlock/enable" },

    } },

    { "pagecache",  "Page cache", 0, {

        { REQ,      "/sys/kernel/debug/tracing/events/filemap/enable" },

        { REQ,      "events/filemap/enable" },

    } },

};
@@ -205,61 +205,62 @@ static const char* g_outputFile = nullptr; 
/* Global state */

static bool g_traceAborted = false;

static bool g_categoryEnables[NELEM(k_categories)] = {};

static std::string g_traceFolder;



/* Sys file paths */

static const char* k_traceClockPath =

    "/sys/kernel/debug/tracing/trace_clock";

    "trace_clock";



static const char* k_traceBufferSizePath =

    "/sys/kernel/debug/tracing/buffer_size_kb";

    "buffer_size_kb";



static const char* k_tracingOverwriteEnablePath =

    "/sys/kernel/debug/tracing/options/overwrite";

    "options/overwrite";



static const char* k_currentTracerPath =

    "/sys/kernel/debug/tracing/current_tracer";

    "current_tracer";



static const char* k_printTgidPath =

    "/sys/kernel/debug/tracing/options/print-tgid";

    "options/print-tgid";



static const char* k_funcgraphAbsTimePath =

    "/sys/kernel/debug/tracing/options/funcgraph-abstime";

    "options/funcgraph-abstime";



static const char* k_funcgraphCpuPath =

    "/sys/kernel/debug/tracing/options/funcgraph-cpu";

    "options/funcgraph-cpu";



static const char* k_funcgraphProcPath =

    "/sys/kernel/debug/tracing/options/funcgraph-proc";

    "options/funcgraph-proc";



static const char* k_funcgraphFlatPath =

    "/sys/kernel/debug/tracing/options/funcgraph-flat";

    "options/funcgraph-flat";



static const char* k_funcgraphDurationPath =

    "/sys/kernel/debug/tracing/options/funcgraph-duration";

    "options/funcgraph-duration";



static const char* k_ftraceFilterPath =

    "/sys/kernel/debug/tracing/set_ftrace_filter";

    "set_ftrace_filter";



static const char* k_tracingOnPath =

    "/sys/kernel/debug/tracing/tracing_on";

    "tracing_on";



static const char* k_tracePath =

    "/sys/kernel/debug/tracing/trace";

    "trace";



static const char* k_traceStreamPath =

    "/sys/kernel/debug/tracing/trace_pipe";

    "trace_pipe";



static const char* k_traceMarkerPath =

    "/sys/kernel/debug/tracing/trace_marker";

    "trace_marker";



// Check whether a file exists.

static bool fileExists(const char* filename) {

    return access(filename, F_OK) != -1;

    return access((g_traceFolder + filename).c_str(), F_OK) != -1;

}



// Check whether a file is writable.

static bool fileIsWritable(const char* filename) {

    return access(filename, W_OK) != -1;

    return access((g_traceFolder + filename).c_str(), W_OK) != -1;

}



// Truncate a file.
@@ -268,9 +269,9 @@ static bool truncateFile(const char* path) 
    // This uses creat rather than truncate because some of the debug kernel

    // device nodes (e.g. k_ftraceFilterPath) currently aren't changed by

    // calls to truncate, but they are cleared by calls to creat.

    int traceFD = creat(path, 0);

    int traceFD = creat((g_traceFolder + path).c_str(), 0);

    if (traceFD == -1) {

        fprintf(stderr, "error truncating %s: %s (%d)\n", path,

        fprintf(stderr, "error truncating %s: %s (%d)\n", (g_traceFolder + path).c_str(),

            strerror(errno), errno);

        return false;

    }
@@ -282,9 +283,10 @@ static bool truncateFile(const char* path) 


static bool _writeStr(const char* filename, const char* str, int flags)

{

    int fd = open(filename, flags);

    std::string fullFilename = g_traceFolder + filename;

    int fd = open(fullFilename.c_str(), flags);

    if (fd == -1) {

        fprintf(stderr, "error opening %s: %s (%d)\n", filename,

        fprintf(stderr, "error opening %s: %s (%d)\n", fullFilename.c_str(),

                strerror(errno), errno);

        return false;

    }
@@ -292,7 +294,7 @@ static bool _writeStr(const char* filename, const char* str, int flags) 
    bool ok = true;

    ssize_t len = strlen(str);

    if (write(fd, str, len) != len) {

        fprintf(stderr, "error writing to %s: %s (%d)\n", filename,

        fprintf(stderr, "error writing to %s: %s (%d)\n", fullFilename.c_str(),

                strerror(errno), errno);

        ok = false;

    }
@@ -318,7 +320,7 @@ static void writeClockSyncMarker() 
{

  char buffer[128];

  int len = 0;

  int fd = open(k_traceMarkerPath, O_WRONLY);

  int fd = open((g_traceFolder + k_traceMarkerPath).c_str(), O_WRONLY);

  if (fd == -1) {

      fprintf(stderr, "error opening %s: %s (%d)\n", k_traceMarkerPath,

              strerror(errno), errno);
@@ -439,7 +441,7 @@ static bool setTraceBufferSizeKB(int size) 
// local [global] counter uptime perf

static bool isTraceClock(const char *mode)

{

    int fd = open(k_traceClockPath, O_RDONLY);

    int fd = open((g_traceFolder + k_traceClockPath).c_str(), O_RDONLY);

    if (fd == -1) {

        fprintf(stderr, "error opening %s: %s (%d)\n", k_traceClockPath,

            strerror(errno), errno);
@@ -652,7 +654,7 @@ static bool disableKernelTraceEvents() { 
static bool verifyKernelTraceFuncs(const char* funcs)

{

    std::string buf;

    if (!android::base::ReadFileToString(k_ftraceFilterPath, &buf)) {

    if (!android::base::ReadFileToString(g_traceFolder + k_ftraceFilterPath, &buf)) {

         fprintf(stderr, "error opening %s: %s (%d)\n", k_ftraceFilterPath,

            strerror(errno), errno);

         return false;
@@ -873,7 +875,7 @@ static void stopTrace() 
static void streamTrace()

{

    char trace_data[4096];

    int traceFD = open(k_traceStreamPath, O_RDWR);

    int traceFD = open((g_traceFolder + k_traceStreamPath).c_str(), O_RDWR);

    if (traceFD == -1) {

        fprintf(stderr, "error opening %s: %s (%d)\n", k_traceStreamPath,

                strerror(errno), errno);
@@ -898,7 +900,7 @@ static void streamTrace() 
static void dumpTrace(int outFd)

{

    ALOGI("Dumping trace");

    int traceFD = open(k_tracePath, O_RDWR);

    int traceFD = open((g_traceFolder + k_tracePath).c_str(), O_RDWR);

    if (traceFD == -1) {

        fprintf(stderr, "error opening %s: %s (%d)\n", k_tracePath,

                strerror(errno), errno);
@@ -1053,6 +1055,29 @@ static void showHelp(const char *cmd) 
            );

}



bool findTraceFiles()

{

    static const std::string debugfs_path = "/sys/kernel/debug/tracing/";

    static const std::string tracefs_path = "/sys/kernel/tracing/";

    static const std::string trace_file = "trace_marker";



    bool tracefs = access((tracefs_path + trace_file).c_str(), F_OK) != -1;

    bool debugfs = access((debugfs_path + trace_file).c_str(), F_OK) != -1;



    if (!tracefs && !debugfs) {

        fprintf(stderr, "Error: Did not find trace folder\n");

        return false;

    }



    if (tracefs) {

        g_traceFolder = tracefs_path;

    } else {

        g_traceFolder = debugfs_path;

    }



    return true;

}



int main(int argc, char **argv)

{

    bool async = false;
@@ -1066,6 +1091,11 @@ int main(int argc, char **argv) 
        exit(0);

    }



    if (!findTraceFiles()) {

        fprintf(stderr, "No trace folder found\n");

        exit(-1);

    }



    for (;;) {

        int ret;

        int option_index = 0;

cmds/atrace/atrace.rc

+59 −0
Original line number Diff line number Diff line
@@ -4,72 +4,131 @@ on post-fs 


# Allow writing to the kernel trace log.

    chmod 0222 /sys/kernel/debug/tracing/trace_marker

    chmod 0222 /sys/kernel/tracing/trace_marker



# Allow the shell group to enable (some) kernel tracing.

    chown root shell /sys/kernel/debug/tracing/trace_clock

    chown root shell /sys/kernel/tracing/trace_clock

    chown root shell /sys/kernel/debug/tracing/buffer_size_kb

    chown root shell /sys/kernel/tracing/buffer_size_kb

    chown root shell /sys/kernel/debug/tracing/options/overwrite

    chown root shell /sys/kernel/tracing/options/overwrite

    chown root shell /sys/kernel/debug/tracing/options/print-tgid

    chown root shell /sys/kernel/tracing/options/print-tgid

    chown root shell /sys/kernel/debug/tracing/events/sched/sched_switch/enable

    chown root shell /sys/kernel/tracing/events/sched/sched_switch/enable

    chown root shell /sys/kernel/debug/tracing/events/sched/sched_wakeup/enable

    chown root shell /sys/kernel/tracing/events/sched/sched_wakeup/enable

    chown root shell /sys/kernel/debug/tracing/events/sched/sched_blocked_reason/enable

    chown root shell /sys/kernel/tracing/events/sched/sched_blocked_reason/enable

    chown root shell /sys/kernel/debug/tracing/events/sched/sched_cpu_hotplug/enable

    chown root shell /sys/kernel/tracing/events/sched/sched_cpu_hotplug/enable

    chown root shell /sys/kernel/debug/tracing/events/power/cpu_frequency/enable

    chown root shell /sys/kernel/tracing/events/power/cpu_frequency/enable

    chown root shell /sys/kernel/debug/tracing/events/power/cpu_idle/enable

    chown root shell /sys/kernel/tracing/events/power/cpu_idle/enable

    chown root shell /sys/kernel/debug/tracing/events/power/clock_set_rate/enable

    chown root shell /sys/kernel/tracing/events/power/clock_set_rate/enable

    chown root shell /sys/kernel/debug/tracing/events/power/cpu_frequency_limits/enable

    chown root shell /sys/kernel/tracing/events/power/cpu_frequency_limits/enable

    chown root shell /sys/kernel/debug/tracing/events/cpufreq_interactive/enable

    chown root shell /sys/kernel/tracing/events/cpufreq_interactive/enable

    chown root shell /sys/kernel/debug/tracing/events/vmscan/mm_vmscan_direct_reclaim_begin/enable

    chown root shell /sys/kernel/tracing/events/vmscan/mm_vmscan_direct_reclaim_begin/enable

    chown root shell /sys/kernel/debug/tracing/events/vmscan/mm_vmscan_direct_reclaim_end/enable

    chown root shell /sys/kernel/tracing/events/vmscan/mm_vmscan_direct_reclaim_end/enable

    chown root shell /sys/kernel/debug/tracing/events/vmscan/mm_vmscan_kswapd_wake/enable

    chown root shell /sys/kernel/tracing/events/vmscan/mm_vmscan_kswapd_wake/enable

    chown root shell /sys/kernel/debug/tracing/events/vmscan/mm_vmscan_kswapd_sleep/enable

    chown root shell /sys/kernel/tracing/events/vmscan/mm_vmscan_kswapd_sleep/enable

    chown root shell /sys/kernel/debug/tracing/events/binder/binder_transaction/enable

    chown root shell /sys/kernel/tracing/events/binder/binder_transaction/enable

    chown root shell /sys/kernel/debug/tracing/events/binder/binder_transaction_received/enable

    chown root shell /sys/kernel/tracing/events/binder/binder_transaction_received/enable

    chown root shell /sys/kernel/debug/tracing/events/binder/binder_lock/enable

    chown root shell /sys/kernel/tracing/events/binder/binder_lock/enable

    chown root shell /sys/kernel/debug/tracing/events/binder/binder_locked/enable

    chown root shell /sys/kernel/tracing/events/binder/binder_locked/enable

    chown root shell /sys/kernel/debug/tracing/events/binder/binder_unlock/enable

    chown root shell /sys/kernel/tracing/events/binder/binder_unlock/enable



    chown root shell /sys/kernel/debug/tracing/tracing_on

    chown root shell /sys/kernel/tracing/tracing_on



    chmod 0664 /sys/kernel/debug/tracing/trace_clock

    chmod 0664 /sys/kernel/tracing/trace_clock

    chmod 0664 /sys/kernel/debug/tracing/buffer_size_kb

    chmod 0664 /sys/kernel/tracing/buffer_size_kb

    chmod 0664 /sys/kernel/debug/tracing/options/overwrite

    chmod 0664 /sys/kernel/tracing/options/overwrite

    chmod 0664 /sys/kernel/debug/tracing/options/print-tgid

    chmod 0664 /sys/kernel/tracing/options/print-tgid

    chmod 0664 /sys/kernel/debug/tracing/events/sched/sched_switch/enable

    chmod 0664 /sys/kernel/tracing/events/sched/sched_switch/enable

    chmod 0664 /sys/kernel/debug/tracing/events/sched/sched_wakeup/enable

    chmod 0664 /sys/kernel/tracing/events/sched/sched_wakeup/enable

    chmod 0664 /sys/kernel/debug/tracing/events/sched/sched_blocked_reason/enable

    chmod 0664 /sys/kernel/tracing/events/sched/sched_blocked_reason/enable

    chmod 0664 /sys/kernel/debug/tracing/events/sched/sched_cpu_hotplug/enable

    chmod 0664 /sys/kernel/tracing/events/sched/sched_cpu_hotplug/enable

    chmod 0664 /sys/kernel/debug/tracing/events/power/cpu_frequency/enable

    chmod 0664 /sys/kernel/tracing/events/power/cpu_frequency/enable

    chmod 0664 /sys/kernel/debug/tracing/events/power/cpu_idle/enable

    chmod 0664 /sys/kernel/tracing/events/power/cpu_idle/enable

    chmod 0664 /sys/kernel/debug/tracing/events/power/clock_set_rate/enable

    chmod 0664 /sys/kernel/tracing/events/power/clock_set_rate/enable

    chmod 0664 /sys/kernel/debug/tracing/events/power/cpu_frequency_limits/enable

    chmod 0664 /sys/kernel/tracing/events/power/cpu_frequency_limits/enable

    chmod 0664 /sys/kernel/debug/tracing/events/cpufreq_interactive/enable

    chmod 0664 /sys/kernel/tracing/events/cpufreq_interactive/enable

    chmod 0664 /sys/kernel/debug/tracing/events/vmscan/mm_vmscan_direct_reclaim_begin/enable

    chmod 0664 /sys/kernel/tracing/events/vmscan/mm_vmscan_direct_reclaim_begin/enable

    chmod 0664 /sys/kernel/debug/tracing/events/vmscan/mm_vmscan_direct_reclaim_end/enable

    chmod 0664 /sys/kernel/tracing/events/vmscan/mm_vmscan_direct_reclaim_end/enable

    chmod 0664 /sys/kernel/debug/tracing/events/vmscan/mm_vmscan_kswapd_wake/enable

    chmod 0664 /sys/kernel/tracing/events/vmscan/mm_vmscan_kswapd_wake/enable

    chmod 0664 /sys/kernel/debug/tracing/events/vmscan/mm_vmscan_kswapd_sleep/enable

    chmod 0664 /sys/kernel/tracing/events/vmscan/mm_vmscan_kswapd_sleep/enable

    chmod 0664 /sys/kernel/debug/tracing/tracing_on

    chmod 0664 /sys/kernel/tracing/tracing_on

    chmod 0664 /sys/kernel/debug/tracing/events/binder/binder_transaction/enable

    chmod 0664 /sys/kernel/tracing/events/binder/binder_transaction/enable

    chmod 0664 /sys/kernel/debug/tracing/events/binder/binder_transaction_received/enable

    chmod 0664 /sys/kernel/tracing/events/binder/binder_transaction_received/enable

    chmod 0664 /sys/kernel/debug/tracing/events/binder/binder_lock/enable

    chmod 0664 /sys/kernel/tracing/events/binder/binder_lock/enable

    chmod 0664 /sys/kernel/debug/tracing/events/binder/binder_locked/enable

    chmod 0664 /sys/kernel/tracing/events/binder/binder_locked/enable

    chmod 0664 /sys/kernel/debug/tracing/events/binder/binder_unlock/enable

    chmod 0664 /sys/kernel/tracing/events/binder/binder_unlock/enable

    chmod 0664 /sys/kernel/debug/tracing/events/i2c/enable

    chmod 0664 /sys/kernel/tracing/events/i2c/enable

    chmod 0664 /sys/kernel/debug/tracing/events/i2c/i2c_read/enable

    chmod 0664 /sys/kernel/tracing/events/i2c/i2c_read/enable

    chmod 0664 /sys/kernel/debug/tracing/events/i2c/i2c_write/enable

    chmod 0664 /sys/kernel/tracing/events/i2c/i2c_write/enable

    chmod 0664 /sys/kernel/debug/tracing/events/i2c/i2c_result/enable

    chmod 0664 /sys/kernel/tracing/events/i2c/i2c_result/enable

    chmod 0664 /sys/kernel/debug/tracing/events/i2c/i2c_reply/enable

    chmod 0664 /sys/kernel/tracing/events/i2c/i2c_reply/enable

    chmod 0664 /sys/kernel/debug/tracing/events/i2c/smbus_read/enable

    chmod 0664 /sys/kernel/tracing/events/i2c/smbus_read/enable

    chmod 0664 /sys/kernel/debug/tracing/events/i2c/smbus_write/enable

    chmod 0664 /sys/kernel/tracing/events/i2c/smbus_write/enable

    chmod 0664 /sys/kernel/debug/tracing/events/i2c/smbus_result/enable

    chmod 0664 /sys/kernel/tracing/events/i2c/smbus_result/enable

    chmod 0664 /sys/kernel/debug/tracing/events/i2c/smbus_reply/enable

    chmod 0664 /sys/kernel/tracing/events/i2c/smbus_reply/enable



    # Tracing disabled by default

    write /sys/kernel/debug/tracing/tracing_on 0

    write /sys/kernel/tracing/tracing_on 0



# Allow only the shell group to read and truncate the kernel trace.

    chown root shell /sys/kernel/debug/tracing/trace

    chown root shell /sys/kernel/tracing/trace

    chmod 0660 /sys/kernel/debug/tracing/trace

    chmod 0660 /sys/kernel/tracing/trace



on property:persist.debug.atrace.boottrace=1

    start boottrace