Merge "Set the atrace clock to the best available value: boot, mono, or global." into oc-dev (115d6cd1) · Commits · e / os / android_frameworks_native-old

cmds/atrace/atrace.cpp

+21 −46

Original line number	Original line	Diff line number	Diff line
	@@ -30,6 +30,7 @@
	#include <unistd.h>		#include <unistd.h>
	#include <zlib.h>		#include <zlib.h>

			#include <fstream>
	#include <memory>		#include <memory>

	#include <binder/IBinder.h>		#include <binder/IBinder.h>
	@@ -434,56 +435,31 @@ static bool setTraceBufferSizeKB(int size)
	return writeStr(k_traceBufferSizePath, str);		return writeStr(k_traceBufferSizePath, str);
	}		}

	// Read the trace_clock sysfs file and return true if it matches the requested		// Set the clock to the best available option while tracing. Use 'boot' if it's
	// value. The trace_clock file format is:		// available; otherwise, use 'mono'. If neither are available use 'global'.
	// local [global] counter uptime perf
	static bool isTraceClock(const char *mode)
	{
	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);
	return false;
	}

	char buf[4097];
	ssize_t n = read(fd, buf, 4096);
	close(fd);
	if (n == -1) {
	fprintf(stderr, "error reading %s: %s (%d)\n", k_traceClockPath,
	strerror(errno), errno);
	return false;
	}
	buf[n] = '\0';

	char *start = strchr(buf, '[');
	if (start == NULL) {
	return false;
	}
	start++;

	char *end = strchr(start, ']');
	if (end == NULL) {
	return false;
	}
	*end = '\0';

	return strcmp(mode, start) == 0;
	}

	// 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.
	// Any write to the trace_clock sysfs file will reset the buffer, so only		// Any write to the trace_clock sysfs file will reset the buffer, so only
	// update it if the requested value is not the current value.		// update it if the requested value is not the current value.
	static bool setGlobalClockEnable(bool enable)		static bool setClock()
	{		{
	const char *clock = enable ? "global" : "local";		std::ifstream clockFile((g_traceFolder + k_traceClockPath).c_str(), O_RDONLY);
			std::string clockStr((std::istreambuf_iterator<char>(clockFile)),
			std::istreambuf_iterator<char>());

			std::string newClock;
			if (clockStr.find("boot") != std::string::npos) {
			newClock = "boot";
			} else if (clockStr.find("mono") != std::string::npos) {
			newClock = "mono";
			} else {
			newClock = "global";
			}

	if (isTraceClock(clock)) {		size_t begin = clockStr.find("[") + 1;
			size_t end = clockStr.find("]");
			if (newClock.compare(0, std::string::npos, clockStr, begin, end-begin) == 0) {
	return true;		return true;
	}		}
			return writeStr(k_traceClockPath, newClock.c_str());
	return writeStr(k_traceClockPath, clock);
	}		}

	static bool setPrintTgidEnableIfPresent(bool enable)		static bool setPrintTgidEnableIfPresent(bool enable)
	@@ -776,7 +752,7 @@ static bool setUpTrace()
	ok &= setCategoriesEnableFromFile(g_categoriesFile);		ok &= setCategoriesEnableFromFile(g_categoriesFile);
	ok &= setTraceOverwriteEnable(g_traceOverwrite);		ok &= setTraceOverwriteEnable(g_traceOverwrite);
	ok &= setTraceBufferSizeKB(g_traceBufferSizeKB);		ok &= setTraceBufferSizeKB(g_traceBufferSizeKB);
	ok &= setGlobalClockEnable(true);		ok &= setClock();
	ok &= setPrintTgidEnableIfPresent(true);		ok &= setPrintTgidEnableIfPresent(true);
	ok &= setKernelTraceFuncs(g_kernelTraceFuncs);		ok &= setKernelTraceFuncs(g_kernelTraceFuncs);

	@@ -848,7 +824,6 @@ static void cleanUpTrace()
	// Set the options back to their defaults.		// Set the options back to their defaults.
	setTraceOverwriteEnable(true);		setTraceOverwriteEnable(true);
	setTraceBufferSizeKB(1);		setTraceBufferSizeKB(1);
	setGlobalClockEnable(false);
	setPrintTgidEnableIfPresent(false);		setPrintTgidEnableIfPresent(false);
	setKernelTraceFuncs(NULL);		setKernelTraceFuncs(NULL);
	}		}

cmds/atrace/atrace.rc

+5 −0

Original line number	Original line	Diff line number	Diff line
	@@ -124,6 +124,11 @@ on post-fs
	write /sys/kernel/debug/tracing/tracing_on 0		write /sys/kernel/debug/tracing/tracing_on 0
	write /sys/kernel/tracing/tracing_on 0		write /sys/kernel/tracing/tracing_on 0

			# Set the trace clock to boot; falling back to mono or boot
			write /d/tracing/trace_clock global
			write /d/tracing/trace_clock mono
			write /d/tracing/trace_clock boot

	# Allow only the shell group to read and truncate the kernel trace.		# 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/debug/tracing/trace
	chown root shell /sys/kernel/tracing/trace		chown root shell /sys/kernel/tracing/trace