atrace: clean up tracing option enabling
This change switches atrace to use a table-driven approach to enabling and
disabling options. It unifies how framework and kernel tracing are enabled,
and causes userland tracing options to be picked up by currently running
processes.
Change-Id: Iba2a3012ca0a67c4defdd076bce597db26e9f539
diff --git a/cmds/atrace/Android.mk b/cmds/atrace/Android.mk
index 12526d0..028ca8f 100644
--- a/cmds/atrace/Android.mk
+++ b/cmds/atrace/Android.mk
@@ -3,15 +3,18 @@
LOCAL_PATH:= $(call my-dir)
include $(CLEAR_VARS)
-LOCAL_SRC_FILES:= atrace.c
+LOCAL_SRC_FILES:= atrace.cpp
LOCAL_C_INCLUDES += external/zlib
-LOCAL_CFLAGS += -std=c99
LOCAL_MODULE:= atrace
LOCAL_MODULE_TAGS:= optional
-LOCAL_SHARED_LIBRARIES := libz
+LOCAL_SHARED_LIBRARIES := \
+ libbinder \
+ libcutils \
+ libutils \
+ libz \
include $(BUILD_EXECUTABLE)
diff --git a/cmds/atrace/atrace.c b/cmds/atrace/atrace.c
deleted file mode 100644
index 64f13e4..0000000
--- a/cmds/atrace/atrace.c
+++ /dev/null
@@ -1,643 +0,0 @@
-/*
- * Copyright (C) 2012 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 <getopt.h>
-#include <signal.h>
-#include <stdarg.h>
-#include <stdbool.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <sys/sendfile.h>
-#include <time.h>
-#include <zlib.h>
-
-#define NELEM(x) ((int) (sizeof(x) / sizeof((x)[0])))
-
-/* Command line options */
-static int g_traceDurationSeconds = 5;
-static bool g_traceSchedSwitch = false;
-static bool g_traceFrequency = false;
-static bool g_traceBusUtilization = false;
-static bool g_traceCpuIdle = false;
-static bool g_traceDisk = false;
-static bool g_traceGovernorLoad = false;
-static bool g_traceSync = false;
-static bool g_traceWorkqueue = false;
-static bool g_traceOverwrite = false;
-static int g_traceBufferSizeKB = 2048;
-static bool g_compress = false;
-static bool g_nohup = false;
-static int g_initialSleepSecs = 0;
-
-/* Global state */
-static bool g_traceAborted = false;
-
-/* Sys file paths */
-static const char* k_traceClockPath =
- "/sys/kernel/debug/tracing/trace_clock";
-
-static const char* k_traceBufferSizePath =
- "/sys/kernel/debug/tracing/buffer_size_kb";
-
-static const char* k_tracingOverwriteEnablePath =
- "/sys/kernel/debug/tracing/options/overwrite";
-
-static const char* k_schedSwitchEnablePath =
- "/sys/kernel/debug/tracing/events/sched/sched_switch/enable";
-
-static const char* k_schedWakeupEnablePath =
- "/sys/kernel/debug/tracing/events/sched/sched_wakeup/enable";
-
-static const char* k_memoryBusEnablePath =
- "/sys/kernel/debug/tracing/events/memory_bus/enable";
-
-static const char* k_cpuFreqEnablePath =
- "/sys/kernel/debug/tracing/events/power/cpu_frequency/enable";
-
-static const char *k_clockSetRateEnablePath =
- "/sys/kernel/debug/tracing/events/power/clock_set_rate/enable";
-
-static const char* k_cpuIdleEnablePath =
- "/sys/kernel/debug/tracing/events/power/cpu_idle/enable";
-
-static const char* k_governorLoadEnablePath =
- "/sys/kernel/debug/tracing/events/cpufreq_interactive/enable";
-
-static const char* k_syncEnablePath =
- "/sys/kernel/debug/tracing/events/sync/enable";
-
-static const char* k_workqueueEnablePath =
- "/sys/kernel/debug/tracing/events/workqueue/enable";
-
-static const char* k_diskEnablePaths[] = {
- "/sys/kernel/debug/tracing/events/ext4/ext4_sync_file_enter/enable",
- "/sys/kernel/debug/tracing/events/ext4/ext4_sync_file_exit/enable",
- "/sys/kernel/debug/tracing/events/block/block_rq_issue/enable",
- "/sys/kernel/debug/tracing/events/block/block_rq_complete/enable",
-};
-
-static const char* k_tracingOnPath =
- "/sys/kernel/debug/tracing/tracing_on";
-
-static const char* k_tracePath =
- "/sys/kernel/debug/tracing/trace";
-
-static const char* k_traceMarkerPath =
- "/sys/kernel/debug/tracing/trace_marker";
-
-// Check whether a file exists.
-static bool fileExists(const char* filename) {
- return access(filename, F_OK) != -1;
-}
-
-// Write a string to a file, returning true if the write was successful.
-bool writeStr(const char* filename, const char* str)
-{
- int fd = open(filename, O_WRONLY);
- if (fd == -1) {
- fprintf(stderr, "error opening %s: %s (%d)\n", filename,
- strerror(errno), errno);
- return false;
- }
-
- bool ok = true;
- ssize_t len = strlen(str);
- if (write(fd, str, len) != len) {
- fprintf(stderr, "error writing to %s: %s (%d)\n", filename,
- strerror(errno), errno);
- ok = false;
- }
-
- close(fd);
-
- return ok;
-}
-
-// Enable or disable a kernel option by writing a "1" or a "0" into a /sys file.
-static bool setKernelOptionEnable(const char* filename, bool enable)
-{
- return writeStr(filename, enable ? "1" : "0");
-}
-
-// Enable or disable a collection of kernel options by writing a "1" or a "0" into each /sys file.
-static bool setMultipleKernelOptionsEnable(const char** filenames, size_t count, bool enable)
-{
- bool result = true;
- for (size_t i = 0; i < count; i++) {
- result &= setKernelOptionEnable(filenames[i], enable);
- }
- return result;
-}
-
-// Enable or disable overwriting of the kernel trace buffers. Disabling this
-// will cause tracing to stop once the trace buffers have filled up.
-static bool setTraceOverwriteEnable(bool enable)
-{
- return setKernelOptionEnable(k_tracingOverwriteEnablePath, enable);
-}
-
-// Enable or disable tracing of the kernel scheduler switching.
-static bool setSchedSwitchTracingEnable(bool enable)
-{
- bool ok = true;
- ok &= setKernelOptionEnable(k_schedSwitchEnablePath, enable);
- ok &= setKernelOptionEnable(k_schedWakeupEnablePath, enable);
- return ok;
-}
-
-// Enable or disable tracing of the Bus utilization.
-static bool setBusUtilizationTracingEnable(bool enable)
-{
- bool ok = true, oneSet = false;
- // these can be platform specific so make sure that at least
- // one succeeds.
- if (fileExists(k_memoryBusEnablePath)) {
- ok &= setKernelOptionEnable(k_memoryBusEnablePath, enable);
- oneSet |= ok;
- }
- return ok && (oneSet || !enable);
-}
-
-// Enable or disable tracing of the CPU clock frequency.
-static bool setFrequencyTracingEnable(bool enable)
-{
- bool ok = true;
- ok &= setKernelOptionEnable(k_cpuFreqEnablePath, enable);
- if (fileExists(k_clockSetRateEnablePath)) {
- ok &= setKernelOptionEnable(k_clockSetRateEnablePath, enable);
- }
- return ok;
-}
-
-// Enable or disable tracing of CPU idle events.
-static bool setCpuIdleTracingEnable(bool enable)
-{
- return setKernelOptionEnable(k_cpuIdleEnablePath, enable);
-}
-
-// Enable or disable tracing of the interactive CPU frequency governor's idea of
-// the CPU load.
-static bool setGovernorLoadTracingEnable(bool enable)
-{
- bool ok = true;
- if (fileExists(k_governorLoadEnablePath) || enable) {
- ok &= setKernelOptionEnable(k_governorLoadEnablePath, enable);
- }
- return ok;
-}
-
-// Enable or disable tracing of sync timelines and waits.
-static bool setSyncTracingEnabled(bool enable)
-{
- bool ok = true;
- if (fileExists(k_syncEnablePath) || enable) {
- ok &= setKernelOptionEnable(k_syncEnablePath, enable);
- }
- return ok;
-}
-
-// Enable or disable tracing of the kernel workqueues.
-static bool setWorkqueueTracingEnabled(bool enable)
-{
- return setKernelOptionEnable(k_workqueueEnablePath, enable);
-}
-
-// Enable or disable tracing of disk I/O.
-static bool setDiskTracingEnabled(bool enable)
-{
- return setMultipleKernelOptionsEnable(k_diskEnablePaths, NELEM(k_diskEnablePaths), enable);
-}
-
-// Enable or disable kernel tracing.
-static bool setTracingEnabled(bool enable)
-{
- return setKernelOptionEnable(k_tracingOnPath, enable);
-}
-
-// Clear the contents of the kernel trace.
-static bool clearTrace()
-{
- int traceFD = creat(k_tracePath, 0);
- if (traceFD == -1) {
- fprintf(stderr, "error truncating %s: %s (%d)\n", k_tracePath,
- strerror(errno), errno);
- return false;
- }
-
- close(traceFD);
-
- return true;
-}
-
-// Set the size of the kernel's trace buffer in kilobytes.
-static bool setTraceBufferSizeKB(int size)
-{
- char str[32] = "1";
- int len;
- if (size < 1) {
- size = 1;
- }
- snprintf(str, 32, "%d", size);
- return writeStr(k_traceBufferSizePath, str);
-}
-
-// Enable or disable the kernel's use of the global clock. Disabling the global
-// clock will result in the kernel using a per-CPU local clock.
-static bool setGlobalClockEnable(bool enable)
-{
- return writeStr(k_traceClockPath, enable ? "global" : "local");
-}
-
-// Enable tracing in the kernel.
-static bool startTrace(bool isRoot)
-{
- bool ok = true;
-
- // Set up the tracing options that don't require root.
- ok &= setTraceOverwriteEnable(g_traceOverwrite);
- ok &= setSchedSwitchTracingEnable(g_traceSchedSwitch);
- ok &= setFrequencyTracingEnable(g_traceFrequency);
- ok &= setCpuIdleTracingEnable(g_traceCpuIdle);
- ok &= setGovernorLoadTracingEnable(g_traceGovernorLoad);
- ok &= setTraceBufferSizeKB(g_traceBufferSizeKB);
- ok &= setGlobalClockEnable(true);
-
- // Set up the tracing options that do require root. The options that
- // require root should have errored out earlier if we're not running as
- // root.
- if (isRoot) {
- ok &= setBusUtilizationTracingEnable(g_traceBusUtilization);
- ok &= setSyncTracingEnabled(g_traceSync);
- ok &= setWorkqueueTracingEnabled(g_traceWorkqueue);
- ok &= setDiskTracingEnabled(g_traceDisk);
- }
-
- // Enable tracing.
- ok &= setTracingEnabled(true);
-
- if (!ok) {
- fprintf(stderr, "error: unable to start trace\n");
- }
-
- return ok;
-}
-
-// Disable tracing in the kernel.
-static void stopTrace(bool isRoot)
-{
- // Disable tracing.
- setTracingEnabled(false);
-
- // Set the options back to their defaults.
- setTraceOverwriteEnable(true);
- setSchedSwitchTracingEnable(false);
- setFrequencyTracingEnable(false);
- setGovernorLoadTracingEnable(false);
- setGlobalClockEnable(false);
-
- if (isRoot) {
- setBusUtilizationTracingEnable(false);
- setSyncTracingEnabled(false);
- setWorkqueueTracingEnabled(false);
- setDiskTracingEnabled(false);
- }
-
- // Note that we can't reset the trace buffer size here because that would
- // clear the trace before we've read it.
-}
-
-// Read the current kernel trace and write it to stdout.
-static void dumpTrace()
-{
- int traceFD = open(k_tracePath, O_RDWR);
- if (traceFD == -1) {
- fprintf(stderr, "error opening %s: %s (%d)\n", k_tracePath,
- strerror(errno), errno);
- return;
- }
-
- if (g_compress) {
- z_stream zs;
- uint8_t *in, *out;
- int result, flush;
-
- bzero(&zs, sizeof(zs));
- result = deflateInit(&zs, Z_DEFAULT_COMPRESSION);
- if (result != Z_OK) {
- fprintf(stderr, "error initializing zlib: %d\n", result);
- close(traceFD);
- return;
- }
-
- const size_t bufSize = 64*1024;
- in = (uint8_t*)malloc(bufSize);
- out = (uint8_t*)malloc(bufSize);
- flush = Z_NO_FLUSH;
-
- zs.next_out = out;
- zs.avail_out = bufSize;
-
- do {
-
- if (zs.avail_in == 0) {
- // More input is needed.
- result = read(traceFD, in, bufSize);
- if (result < 0) {
- fprintf(stderr, "error reading trace: %s (%d)\n",
- strerror(errno), errno);
- result = Z_STREAM_END;
- break;
- } else if (result == 0) {
- flush = Z_FINISH;
- } else {
- zs.next_in = in;
- zs.avail_in = result;
- }
- }
-
- if (zs.avail_out == 0) {
- // Need to write the output.
- result = write(STDOUT_FILENO, out, bufSize);
- if ((size_t)result < bufSize) {
- fprintf(stderr, "error writing deflated trace: %s (%d)\n",
- strerror(errno), errno);
- result = Z_STREAM_END; // skip deflate error message
- zs.avail_out = bufSize; // skip the final write
- break;
- }
- zs.next_out = out;
- zs.avail_out = bufSize;
- }
-
- } while ((result = deflate(&zs, flush)) == Z_OK);
-
- if (result != Z_STREAM_END) {
- fprintf(stderr, "error deflating trace: %s\n", zs.msg);
- }
-
- if (zs.avail_out < bufSize) {
- size_t bytes = bufSize - zs.avail_out;
- result = write(STDOUT_FILENO, out, bytes);
- if ((size_t)result < bytes) {
- fprintf(stderr, "error writing deflated trace: %s (%d)\n",
- strerror(errno), errno);
- }
- }
-
- result = deflateEnd(&zs);
- if (result != Z_OK) {
- fprintf(stderr, "error cleaning up zlib: %d\n", result);
- }
-
- free(in);
- free(out);
- } else {
- ssize_t sent = 0;
- while ((sent = sendfile(STDOUT_FILENO, traceFD, NULL, 64*1024*1024)) > 0);
- if (sent == -1) {
- fprintf(stderr, "error dumping trace: %s (%d)\n", strerror(errno),
- errno);
- }
- }
-
- close(traceFD);
-}
-
-// Print the command usage help to stderr.
-static void showHelp(const char *cmd)
-{
- fprintf(stderr, "usage: %s [options]\n", cmd);
- fprintf(stderr, "options include:\n"
- " -b N use a trace buffer size of N KB\n"
- " -c trace into a circular buffer\n"
- " -d trace disk I/O\n"
- " -f trace clock frequency changes\n"
- " -l trace CPU frequency governor load\n"
- " -s trace the kernel scheduler switches\n"
- " -t N trace for N seconds [defualt 5]\n"
- " -u trace bus utilization\n"
- " -w trace the kernel workqueue\n"
- " -y trace sync timelines and waits\n"
- " -z compress the trace dump\n"
- " --async_start start circular trace and return immediatly\n"
- " --async_dump dump the current contents of circular trace buffer\n"
- " --async_stop stop tracing and dump the current contents of circular\n"
- " trace buffer\n"
- );
-}
-
-static void handleSignal(int signo) {
- if (!g_nohup) {
- g_traceAborted = true;
- }
-}
-
-static void registerSigHandler() {
- struct sigaction sa;
- sigemptyset(&sa.sa_mask);
- sa.sa_flags = 0;
- sa.sa_handler = handleSignal;
- sigaction(SIGHUP, &sa, NULL);
- sigaction(SIGINT, &sa, NULL);
- sigaction(SIGQUIT, &sa, NULL);
- sigaction(SIGTERM, &sa, NULL);
-}
-
-int main(int argc, char **argv)
-{
- bool isRoot = (getuid() == 0);
- bool async = false;
- bool traceStart = true;
- bool traceStop = true;
- bool traceDump = true;
-
- if (argc == 2 && 0 == strcmp(argv[1], "--help")) {
- showHelp(argv[0]);
- exit(0);
- }
-
- for (;;) {
- int ret;
- int option_index = 0;
- static struct option long_options[] = {
- {"async_start", no_argument, 0, 0 },
- {"async_stop", no_argument, 0, 0 },
- {"async_dump", no_argument, 0, 0 },
- {0, 0, 0, 0 }
- };
-
- ret = getopt_long(argc, argv, "b:cidflst:uwyznS:",
- long_options, &option_index);
-
- if (ret < 0) {
- break;
- }
-
- switch(ret) {
- case 'b':
- g_traceBufferSizeKB = atoi(optarg);
- break;
-
- case 'c':
- g_traceOverwrite = true;
- break;
-
- case 'i':
- g_traceCpuIdle = true;
- break;
-
- case 'l':
- g_traceGovernorLoad = true;
- break;
-
- case 'd':
- if (!isRoot) {
- fprintf(stderr, "error: tracing disk activity requires root privileges\n");
- exit(1);
- }
- g_traceDisk = true;
- break;
-
- case 'f':
- g_traceFrequency = true;
- break;
-
- case 'n':
- g_nohup = true;
- break;
-
- case 's':
- g_traceSchedSwitch = true;
- break;
-
- case 'S':
- g_initialSleepSecs = atoi(optarg);
- break;
-
- case 't':
- g_traceDurationSeconds = atoi(optarg);
- break;
-
- case 'u':
- if (!isRoot) {
- fprintf(stderr, "error: tracing bus utilization requires root privileges\n");
- exit(1);
- }
- g_traceBusUtilization = true;
- break;
-
- case 'w':
- if (!isRoot) {
- fprintf(stderr, "error: tracing kernel work queues requires root privileges\n");
- exit(1);
- }
- g_traceWorkqueue = true;
- break;
-
- case 'y':
- if (!isRoot) {
- fprintf(stderr, "error: tracing sync requires root privileges\n");
- exit(1);
- }
- g_traceSync = true;
- break;
-
- case 'z':
- g_compress = true;
- break;
-
- case 0:
- if (!strcmp(long_options[option_index].name, "async_start")) {
- async = true;
- traceStop = false;
- traceDump = false;
- g_traceOverwrite = true;
- } else if (!strcmp(long_options[option_index].name, "async_stop")) {
- async = true;
- traceStop = false;
- } else if (!strcmp(long_options[option_index].name, "async_dump")) {
- async = true;
- traceStart = false;
- traceStop = false;
- }
- break;
-
- default:
- fprintf(stderr, "\n");
- showHelp(argv[0]);
- exit(-1);
- break;
- }
- }
-
- registerSigHandler();
-
- if (g_initialSleepSecs > 0) {
- sleep(g_initialSleepSecs);
- }
-
- bool ok = startTrace(isRoot);
-
- if (ok && traceStart) {
- printf("capturing trace...");
- fflush(stdout);
-
- // We clear the trace after starting it because tracing gets enabled for
- // each CPU individually in the kernel. Having the beginning of the trace
- // contain entries from only one CPU can cause "begin" entries without a
- // matching "end" entry to show up if a task gets migrated from one CPU to
- // another.
- ok = clearTrace();
-
- if (ok && !async) {
- // Sleep to allow the trace to be captured.
- struct timespec timeLeft;
- timeLeft.tv_sec = g_traceDurationSeconds;
- timeLeft.tv_nsec = 0;
- do {
- if (g_traceAborted) {
- break;
- }
- } while (nanosleep(&timeLeft, &timeLeft) == -1 && errno == EINTR);
- }
- }
-
- // Stop the trace and restore the default settings.
- if (traceStop)
- stopTrace(isRoot);
-
- if (ok && traceDump) {
- if (!g_traceAborted) {
- printf(" done\nTRACE:\n");
- fflush(stdout);
- dumpTrace();
- } else {
- printf("\ntrace aborted.\n");
- fflush(stdout);
- }
- clearTrace();
- } else if (!ok) {
- fprintf(stderr, "unable to start tracing\n");
- }
-
- // Reset the trace buffer size to 1.
- if (traceStop)
- setTraceBufferSizeKB(1);
-
- return g_traceAborted ? 1 : 0;
-}
diff --git a/cmds/atrace/atrace.cpp b/cmds/atrace/atrace.cpp
new file mode 100644
index 0000000..a4bf674
--- /dev/null
+++ b/cmds/atrace/atrace.cpp
@@ -0,0 +1,711 @@
+/*
+ * Copyright (C) 2012 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 <getopt.h>
+#include <signal.h>
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/sendfile.h>
+#include <time.h>
+#include <zlib.h>
+
+#include <binder/IBinder.h>
+#include <binder/IServiceManager.h>
+#include <binder/Parcel.h>
+
+#include <cutils/properties.h>
+
+#include <utils/String8.h>
+#include <utils/Trace.h>
+
+using namespace android;
+
+#define NELEM(x) ((int) (sizeof(x) / sizeof((x)[0])))
+
+enum { MAX_SYS_FILES = 8 };
+
+const char* k_traceTagsProperty = "debug.atrace.tags.enableflags";
+
+typedef enum { OPT, REQ } requiredness ;
+
+struct TracingCategory {
+ // The name identifying the category.
+ const char* name;
+
+ // A longer description of the category.
+ const char* longname;
+
+ // The userland tracing tags that the category enables.
+ uint64_t tags;
+
+ // The fname==NULL terminated list of /sys/ files that the category
+ // enables.
+ struct {
+ // Whether the file must be writable in order to enable the tracing
+ // category.
+ requiredness required;
+
+ // The path to the enable file.
+ const char* path;
+ } sysfiles[MAX_SYS_FILES];
+};
+
+/* Tracing categories */
+static const TracingCategory k_categories[] = {
+ { "gfx", "Graphics", ATRACE_TAG_GRAPHICS, { } },
+ { "input", "Input", ATRACE_TAG_INPUT, { } },
+ { "view", "View System", ATRACE_TAG_VIEW, { } },
+ { "wm", "Window Manager", ATRACE_TAG_WINDOW_MANAGER, { } },
+ { "am", "Activity Manager", ATRACE_TAG_ACTIVITY_MANAGER, { } },
+ { "audio", "Audio", ATRACE_TAG_AUDIO, { } },
+ { "video", "Video", ATRACE_TAG_VIDEO, { } },
+ { "camera", "Camera", ATRACE_TAG_CAMERA, { } },
+ { "sched", "CPU Scheduling", 0, {
+ { REQ, "/sys/kernel/debug/tracing/events/sched/sched_switch/enable" },
+ { REQ, "/sys/kernel/debug/tracing/events/sched/sched_wakeup/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" },
+ } },
+ { "membus", "Memory Bus Utilization", 0, {
+ { REQ, "/sys/kernel/debug/tracing/events/memory_bus/enable" },
+ } },
+ { "idle", "CPU Idle", 0, {
+ { REQ, "/sys/kernel/debug/tracing/events/power/cpu_idle/enable" },
+ } },
+ { "disk", "Disk I/O", 0, {
+ { REQ, "/sys/kernel/debug/tracing/events/ext4/ext4_sync_file_enter/enable" },
+ { REQ, "/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" },
+ } },
+ { "load", "CPU Load", 0, {
+ { REQ, "/sys/kernel/debug/tracing/events/cpufreq_interactive/enable" },
+ } },
+ { "sync", "Synchronization", 0, {
+ { REQ, "/sys/kernel/debug/tracing/events/sync/enable" },
+ } },
+ { "workq", "Kernel Workqueues", 0, {
+ { REQ, "/sys/kernel/debug/tracing/events/workqueue/enable" },
+ } },
+};
+
+/* Command line options */
+static int g_traceDurationSeconds = 5;
+static bool g_traceOverwrite = false;
+static int g_traceBufferSizeKB = 2048;
+static bool g_compress = false;
+static bool g_nohup = false;
+static int g_initialSleepSecs = 0;
+
+/* Global state */
+static bool g_traceAborted = false;
+static bool g_categoryEnables[NELEM(k_categories)] = {};
+
+/* Sys file paths */
+static const char* k_traceClockPath =
+ "/sys/kernel/debug/tracing/trace_clock";
+
+static const char* k_traceBufferSizePath =
+ "/sys/kernel/debug/tracing/buffer_size_kb";
+
+static const char* k_tracingOverwriteEnablePath =
+ "/sys/kernel/debug/tracing/options/overwrite";
+
+static const char* k_tracingOnPath =
+ "/sys/kernel/debug/tracing/tracing_on";
+
+static const char* k_tracePath =
+ "/sys/kernel/debug/tracing/trace";
+
+// Check whether a file exists.
+static bool fileExists(const char* filename) {
+ return access(filename, F_OK) != -1;
+}
+
+// Check whether a file is writable.
+static bool fileIsWritable(const char* filename) {
+ return access(filename, W_OK) != -1;
+}
+
+// Write a string to a file, returning true if the write was successful.
+static bool writeStr(const char* filename, const char* str)
+{
+ int fd = open(filename, O_WRONLY);
+ if (fd == -1) {
+ fprintf(stderr, "error opening %s: %s (%d)\n", filename,
+ strerror(errno), errno);
+ return false;
+ }
+
+ bool ok = true;
+ ssize_t len = strlen(str);
+ if (write(fd, str, len) != len) {
+ fprintf(stderr, "error writing to %s: %s (%d)\n", filename,
+ strerror(errno), errno);
+ ok = false;
+ }
+
+ close(fd);
+
+ return ok;
+}
+
+// Enable or disable a kernel option by writing a "1" or a "0" into a /sys
+// file.
+static bool setKernelOptionEnable(const char* filename, bool enable)
+{
+ return writeStr(filename, enable ? "1" : "0");
+}
+
+// Check whether the category is supported on the device with the current
+// rootness. A category is supported only if all its required /sys/ files are
+// writable and if enabling the category will enable one or more tracing tags
+// or /sys/ files.
+static bool isCategorySupported(const TracingCategory& category)
+{
+ bool ok = category.tags != 0;
+ for (int i = 0; i < MAX_SYS_FILES; i++) {
+ const char* path = category.sysfiles[i].path;
+ bool req = category.sysfiles[i].required == REQ;
+ if (path != NULL) {
+ if (req) {
+ if (!fileIsWritable(path)) {
+ return false;
+ } else {
+ ok = true;
+ }
+ } else {
+ ok |= fileIsWritable(path);
+ }
+ }
+ }
+ return ok;
+}
+
+// Check whether the category would be supported on the device if the user
+// were root. This function assumes that root is able to write to any file
+// that exists. It performs the same logic as isCategorySupported, but it
+// uses file existance rather than writability in the /sys/ file checks.
+static bool isCategorySupportedForRoot(const TracingCategory& category)
+{
+ bool ok = category.tags != 0;
+ for (int i = 0; i < MAX_SYS_FILES; i++) {
+ const char* path = category.sysfiles[i].path;
+ bool req = category.sysfiles[i].required == REQ;
+ if (path != NULL) {
+ if (req) {
+ if (!fileExists(path)) {
+ return false;
+ } else {
+ ok = true;
+ }
+ } else {
+ ok |= fileExists(path);
+ }
+ }
+ }
+ return ok;
+}
+
+// Enable or disable overwriting of the kernel trace buffers. Disabling this
+// will cause tracing to stop once the trace buffers have filled up.
+static bool setTraceOverwriteEnable(bool enable)
+{
+ return setKernelOptionEnable(k_tracingOverwriteEnablePath, enable);
+}
+
+// Enable or disable kernel tracing.
+static bool setTracingEnabled(bool enable)
+{
+ return setKernelOptionEnable(k_tracingOnPath, enable);
+}
+
+// Clear the contents of the kernel trace.
+static bool clearTrace()
+{
+ int traceFD = creat(k_tracePath, 0);
+ if (traceFD == -1) {
+ fprintf(stderr, "error truncating %s: %s (%d)\n", k_tracePath,
+ strerror(errno), errno);
+ return false;
+ }
+
+ close(traceFD);
+
+ return true;
+}
+
+// Set the size of the kernel's trace buffer in kilobytes.
+static bool setTraceBufferSizeKB(int size)
+{
+ char str[32] = "1";
+ int len;
+ if (size < 1) {
+ size = 1;
+ }
+ snprintf(str, 32, "%d", size);
+ return writeStr(k_traceBufferSizePath, str);
+}
+
+// Enable or disable the kernel's use of the global clock. Disabling the global
+// clock will result in the kernel using a per-CPU local clock.
+static bool setGlobalClockEnable(bool enable)
+{
+ return writeStr(k_traceClockPath, enable ? "global" : "local");
+}
+
+// Poke all the binder-enabled processes in the system to get them to re-read
+// their system properties.
+static bool pokeBinderServices()
+{
+ sp<IServiceManager> sm = defaultServiceManager();
+ Vector<String16> services = sm->listServices();
+ for (size_t i = 0; i < services.size(); i++) {
+ sp<IBinder> obj = sm->checkService(services[i]);
+ if (obj != NULL) {
+ Parcel data;
+ if (obj->transact(IBinder::SYSPROPS_TRANSACTION, data,
+ NULL, 0) != OK) {
+ if (false) {
+ // XXX: For some reason this fails on tablets trying to
+ // poke the "phone" service. It's not clear whether some
+ // are expected to fail.
+ String8 svc(services[i]);
+ fprintf(stderr, "error poking binder service %s\n",
+ svc.string());
+ return false;
+ }
+ }
+ }
+ }
+ return true;
+}
+
+// Set the trace tags that userland tracing uses, and poke the running
+// processes to pick up the new value.
+static bool setTagsProperty(uint64_t tags)
+{
+ char buf[64];
+ snprintf(buf, 64, "%#llx", tags);
+ if (property_set(k_traceTagsProperty, buf) < 0) {
+ fprintf(stderr, "error setting trace tags system property\n");
+ return false;
+ }
+ return pokeBinderServices();
+}
+
+// Disable all /sys/ enable files.
+static bool disableKernelTraceEvents() {
+ bool ok = true;
+ for (int i = 0; i < NELEM(k_categories); i++) {
+ const TracingCategory &c = k_categories[i];
+ for (int j = 0; j < MAX_SYS_FILES; j++) {
+ const char* path = c.sysfiles[j].path;
+ if (path != NULL && fileIsWritable(path)) {
+ ok &= setKernelOptionEnable(path, false);
+ }
+ }
+ }
+ return ok;
+}
+
+// Enable tracing in the kernel.
+static bool startTrace()
+{
+ bool ok = true;
+
+ // Set up the tracing options.
+ ok &= setTraceOverwriteEnable(g_traceOverwrite);
+ ok &= setTraceBufferSizeKB(g_traceBufferSizeKB);
+ ok &= setGlobalClockEnable(true);
+
+ // Set up the tags property.
+ uint64_t tags = 0;
+ for (int i = 0; i < NELEM(k_categories); i++) {
+ if (g_categoryEnables[i]) {
+ const TracingCategory &c = k_categories[i];
+ tags |= c.tags;
+ }
+ }
+ ok &= setTagsProperty(tags);
+
+ // Disable all the sysfs enables. This is done as a separate loop from
+ // the enables to allow the same enable to exist in multiple categories.
+ ok &= disableKernelTraceEvents();
+
+ // Enable all the sysfs enables that are in an enabled category.
+ for (int i = 0; i < NELEM(k_categories); i++) {
+ if (g_categoryEnables[i]) {
+ const TracingCategory &c = k_categories[i];
+ for (int j = 0; j < MAX_SYS_FILES; j++) {
+ const char* path = c.sysfiles[j].path;
+ bool required = c.sysfiles[j].required == REQ;
+ if (path != NULL) {
+ if (fileIsWritable(path)) {
+ ok &= setKernelOptionEnable(path, true);
+ } else if (required) {
+ fprintf(stderr, "error writing file %s\n", path);
+ ok = false;
+ }
+ }
+ }
+ }
+ }
+
+ // Enable tracing.
+ ok &= setTracingEnabled(true);
+
+ return ok;
+}
+
+// Disable tracing in the kernel.
+static void stopTrace()
+{
+ // Disable tracing.
+ setTracingEnabled(false);
+
+ // Disable all tracing that we're able to.
+ disableKernelTraceEvents();
+
+ // Disable all the trace tags.
+ setTagsProperty(0);
+
+ // Set the options back to their defaults.
+ setTraceOverwriteEnable(true);
+ setGlobalClockEnable(false);
+
+ // Note that we can't reset the trace buffer size here because that would
+ // clear the trace before we've read it.
+}
+
+// Read the current kernel trace and write it to stdout.
+static void dumpTrace()
+{
+ int traceFD = open(k_tracePath, O_RDWR);
+ if (traceFD == -1) {
+ fprintf(stderr, "error opening %s: %s (%d)\n", k_tracePath,
+ strerror(errno), errno);
+ return;
+ }
+
+ if (g_compress) {
+ z_stream zs;
+ uint8_t *in, *out;
+ int result, flush;
+
+ bzero(&zs, sizeof(zs));
+ result = deflateInit(&zs, Z_DEFAULT_COMPRESSION);
+ if (result != Z_OK) {
+ fprintf(stderr, "error initializing zlib: %d\n", result);
+ close(traceFD);
+ return;
+ }
+
+ const size_t bufSize = 64*1024;
+ in = (uint8_t*)malloc(bufSize);
+ out = (uint8_t*)malloc(bufSize);
+ flush = Z_NO_FLUSH;
+
+ zs.next_out = out;
+ zs.avail_out = bufSize;
+
+ do {
+
+ if (zs.avail_in == 0) {
+ // More input is needed.
+ result = read(traceFD, in, bufSize);
+ if (result < 0) {
+ fprintf(stderr, "error reading trace: %s (%d)\n",
+ strerror(errno), errno);
+ result = Z_STREAM_END;
+ break;
+ } else if (result == 0) {
+ flush = Z_FINISH;
+ } else {
+ zs.next_in = in;
+ zs.avail_in = result;
+ }
+ }
+
+ if (zs.avail_out == 0) {
+ // Need to write the output.
+ result = write(STDOUT_FILENO, out, bufSize);
+ if ((size_t)result < bufSize) {
+ fprintf(stderr, "error writing deflated trace: %s (%d)\n",
+ strerror(errno), errno);
+ result = Z_STREAM_END; // skip deflate error message
+ zs.avail_out = bufSize; // skip the final write
+ break;
+ }
+ zs.next_out = out;
+ zs.avail_out = bufSize;
+ }
+
+ } while ((result = deflate(&zs, flush)) == Z_OK);
+
+ if (result != Z_STREAM_END) {
+ fprintf(stderr, "error deflating trace: %s\n", zs.msg);
+ }
+
+ if (zs.avail_out < bufSize) {
+ size_t bytes = bufSize - zs.avail_out;
+ result = write(STDOUT_FILENO, out, bytes);
+ if ((size_t)result < bytes) {
+ fprintf(stderr, "error writing deflated trace: %s (%d)\n",
+ strerror(errno), errno);
+ }
+ }
+
+ result = deflateEnd(&zs);
+ if (result != Z_OK) {
+ fprintf(stderr, "error cleaning up zlib: %d\n", result);
+ }
+
+ free(in);
+ free(out);
+ } else {
+ ssize_t sent = 0;
+ while ((sent = sendfile(STDOUT_FILENO, traceFD, NULL, 64*1024*1024)) > 0);
+ if (sent == -1) {
+ fprintf(stderr, "error dumping trace: %s (%d)\n", strerror(errno),
+ errno);
+ }
+ }
+
+ close(traceFD);
+}
+
+static void handleSignal(int signo)
+{
+ if (!g_nohup) {
+ g_traceAborted = true;
+ }
+}
+
+static void registerSigHandler()
+{
+ struct sigaction sa;
+ sigemptyset(&sa.sa_mask);
+ sa.sa_flags = 0;
+ sa.sa_handler = handleSignal;
+ sigaction(SIGHUP, &sa, NULL);
+ sigaction(SIGINT, &sa, NULL);
+ sigaction(SIGQUIT, &sa, NULL);
+ sigaction(SIGTERM, &sa, NULL);
+}
+
+static bool setCategoryEnable(const char* name, bool enable)
+{
+ for (int i = 0; i < NELEM(k_categories); i++) {
+ const TracingCategory& c = k_categories[i];
+ if (strcmp(name, c.name) == 0) {
+ if (isCategorySupported(c)) {
+ g_categoryEnables[i] = enable;
+ return true;
+ } else {
+ if (isCategorySupportedForRoot(c)) {
+ fprintf(stderr, "error: category \"%s\" requires root "
+ "privileges.\n", name);
+ } else {
+ fprintf(stderr, "error: category \"%s\" is not supported "
+ "on this device.\n", name);
+ }
+ return false;
+ }
+ }
+ }
+ fprintf(stderr, "error: unknown tracing category \"%s\"\n", name);
+ return false;
+}
+
+static void listSupportedCategories()
+{
+ for (int i = 0; i < NELEM(k_categories); i++) {
+ const TracingCategory& c = k_categories[i];
+ if (isCategorySupported(c)) {
+ printf(" %10s - %s\n", c.name, c.longname);
+ }
+ }
+}
+
+// Print the command usage help to stderr.
+static void showHelp(const char *cmd)
+{
+ fprintf(stderr, "usage: %s [options] [categories...]\n", cmd);
+ fprintf(stderr, "options include:\n"
+ " -b N use a trace buffer size of N KB\n"
+ " -c trace into a circular buffer\n"
+ " -n ignore signals\n"
+ " -s N sleep for N seconds before tracing [default 0]\n"
+ " -t N trace for N seconds [defualt 5]\n"
+ " -z compress the trace dump\n"
+ " --async_start start circular trace and return immediatly\n"
+ " --async_dump dump the current contents of circular trace buffer\n"
+ " --async_stop stop tracing and dump the current contents of circular\n"
+ " trace buffer\n"
+ );
+}
+
+int main(int argc, char **argv)
+{
+ bool async = false;
+ bool traceStart = true;
+ bool traceStop = true;
+ bool traceDump = true;
+
+ if (argc == 2 && 0 == strcmp(argv[1], "--help")) {
+ showHelp(argv[0]);
+ exit(0);
+ }
+
+ for (;;) {
+ int ret;
+ int option_index = 0;
+ static struct option long_options[] = {
+ {"async_start", no_argument, 0, 0 },
+ {"async_stop", no_argument, 0, 0 },
+ {"async_dump", no_argument, 0, 0 },
+ {"list_categories", no_argument, 0, 0 },
+ { 0, 0, 0, 0 }
+ };
+
+ ret = getopt_long(argc, argv, "b:cns:t:z",
+ long_options, &option_index);
+
+ if (ret < 0) {
+ for (int i = optind; i < argc; i++) {
+ if (!setCategoryEnable(argv[i], true)) {
+ fprintf(stderr, "error enabling tracing category \"%s\"\n", argv[i]);
+ exit(1);
+ }
+ }
+ break;
+ }
+
+ switch(ret) {
+ case 'b':
+ g_traceBufferSizeKB = atoi(optarg);
+ break;
+
+ case 'c':
+ g_traceOverwrite = true;
+ break;
+
+ case 'n':
+ g_nohup = true;
+ break;
+
+ case 's':
+ g_initialSleepSecs = atoi(optarg);
+ break;
+
+ case 't':
+ g_traceDurationSeconds = atoi(optarg);
+ break;
+
+ case 'z':
+ g_compress = true;
+ break;
+
+ case 0:
+ if (!strcmp(long_options[option_index].name, "async_start")) {
+ async = true;
+ traceStop = false;
+ traceDump = false;
+ g_traceOverwrite = true;
+ } else if (!strcmp(long_options[option_index].name, "async_stop")) {
+ async = true;
+ traceStop = false;
+ } else if (!strcmp(long_options[option_index].name, "async_dump")) {
+ async = true;
+ traceStart = false;
+ traceStop = false;
+ } else if (!strcmp(long_options[option_index].name, "list_categories")) {
+ listSupportedCategories();
+ exit(0);
+ }
+ break;
+
+ default:
+ fprintf(stderr, "\n");
+ showHelp(argv[0]);
+ exit(-1);
+ break;
+ }
+ }
+
+ registerSigHandler();
+
+ if (g_initialSleepSecs > 0) {
+ sleep(g_initialSleepSecs);
+ }
+
+ bool ok = startTrace();
+
+ if (ok && traceStart) {
+ printf("capturing trace...");
+ fflush(stdout);
+
+ // We clear the trace after starting it because tracing gets enabled for
+ // each CPU individually in the kernel. Having the beginning of the trace
+ // contain entries from only one CPU can cause "begin" entries without a
+ // matching "end" entry to show up if a task gets migrated from one CPU to
+ // another.
+ ok = clearTrace();
+
+ if (ok && !async) {
+ // Sleep to allow the trace to be captured.
+ struct timespec timeLeft;
+ timeLeft.tv_sec = g_traceDurationSeconds;
+ timeLeft.tv_nsec = 0;
+ do {
+ if (g_traceAborted) {
+ break;
+ }
+ } while (nanosleep(&timeLeft, &timeLeft) == -1 && errno == EINTR);
+ }
+ }
+
+ // Stop the trace and restore the default settings.
+ if (traceStop)
+ stopTrace();
+
+ if (ok && traceDump) {
+ if (!g_traceAborted) {
+ printf(" done\nTRACE:\n");
+ fflush(stdout);
+ dumpTrace();
+ } else {
+ printf("\ntrace aborted.\n");
+ fflush(stdout);
+ }
+ clearTrace();
+ } else if (!ok) {
+ fprintf(stderr, "unable to start tracing\n");
+ }
+
+ // Reset the trace buffer size to 1.
+ if (traceStop)
+ setTraceBufferSizeKB(1);
+
+ return g_traceAborted ? 1 : 0;
+}