am e7f3cce7: Merge "logd: Add minimum time bucket statistics" (c76e38ba) · Commits · e / os / android_system_core

logd/LogBuffer.cpp

+19 −2

Original line number	Diff line number	Diff line
		@@ -37,11 +37,11 @@
		LogBuffer::LogBuffer(LastLogTimes *times)
		: mTimes(*times) {
		pthread_mutex_init(&mLogElementsLock, NULL);
		#ifdef USERDEBUG_BUILD
		dgram_qlen_statistics = false;

		log_id_for_each(i) {
		mMaxSize[i] = LOG_BUFFER_SIZE;
		}
		#endif
		}

		void LogBuffer::log(log_id_t log_id, log_time realtime,
		@@ -61,6 +61,23 @@ void LogBuffer::log(log_id_t log_id, log_time realtime,
		LogBufferElementCollection::iterator last = it;
		while (--it != mLogElements.begin()) {
		if ((*it)->getRealTime() <= realtime) {
		// halves the peak performance, use with caution
		if (dgram_qlen_statistics) {
		LogBufferElementCollection::iterator ib = it;
		unsigned short buckets, num = 1;
		for (unsigned short i = 0; (buckets = stats.dgram_qlen(i)); ++i) {
		buckets -= num;
		num += buckets;
		while (buckets && (--ib != mLogElements.begin())) {
		--buckets;
		}
		if (buckets) {
		break;
		}
		stats.recordDiff(
		elem->getRealTime() - (*ib)->getRealTime(), i);
		}
		}
		break;
		}
		last = it;

logd/LogBuffer.h

+7 −0

Original line number	Diff line number	Diff line
		@@ -36,6 +36,8 @@ class LogBuffer {

		LogStatistics stats;

		bool dgram_qlen_statistics;

		#ifdef USERDEBUG_BUILD
		PruneList mPrune;

		@@ -64,6 +66,11 @@ public:
		// *strp uses malloc, use free to release.
		void formatStatistics(char **strp, uid_t uid, unsigned int logMask);

		void enableDgramQlenStatistics() {
		stats.enableDgramQlenStatistics();
		dgram_qlen_statistics = true;
		}

		#ifdef USERDEBUG_BUILD
		int initPrune(char *cp) { return mPrune.init(cp); }
		// *strp uses malloc, use free to release.

logd/LogStatistics.cpp

+133 −3

Original line number	Diff line number	Diff line
		@@ -275,6 +275,66 @@ LogStatistics::LogStatistics()
		mSizes[i] = 0;
		mElements[i] = 0;
		}

		dgram_qlen_statistics = false;
		for(unsigned short bucket = 0; dgram_qlen(bucket); ++bucket) {
		mMinimum[bucket].tv_sec = (uint32_t)-1;
		mMinimum[bucket].tv_nsec = 999999999UL;
		}
		}

		// Each bucket below represents a dgram_qlen of log messages. By
		// finding the minimum period of time from start to finish
		// of each dgram_qlen, we can get a performance expectation for
		// the user space logger. The net result is that the period
		// of time divided by the dgram_qlen will give us the average time
		// between log messages; at the point where the average time
		// is greater than the throughput capability of the logger
		// we will not longer require the benefits of the FIFO formed
		// by max_dgram_qlen. We will also expect to see a very visible
		// knee in the average time between log messages at this point,
		// so we do not necessarily have to compare the rate against the
		// measured performance (BM_log_maximum_retry) of the logger.
		//
		// for example (reformatted):
		//
		// Minimum time between log events per dgram_qlen:
		// 1 2 3 5 10 20 30 50 100 200 300 400 500 600
		// 5u2 12u 13u 15u 16u 27u 30u 36u 407u 3m1 3m3 3m9 3m9 5m5
		//
		// demonstrates a clear knee rising at 100, so this means that for this
		// case max_dgram_qlen = 100 would be more than sufficient to handle the
		// worst that the system could stuff into the logger. The
		// BM_log_maximum_retry performance (derated by the log collection) on the
		// same system was 33.2us so we would almost be fine with max_dgram_qlen = 50.
		// BM_log_maxumum_retry with statistics off is roughly 20us, so
		// max_dgram_qlen = 20 would work. We will be more than willing to have
		// a large engineering margin so the rule of thumb that lead us to 100 is
		// fine.
		//
		// bucket dgram_qlen are tuned for /proc/sys/net/unix/max_dgram_qlen = 300
		const unsigned short LogStatistics::mBuckets[] = {
		1, 2, 3, 5, 10, 20, 30, 50, 100, 200, 300, 400, 500, 600
		};

		unsigned short LogStatistics::dgram_qlen(unsigned short bucket) {
		if (bucket >= sizeof(mBuckets) / sizeof(mBuckets[0])) {
		return 0;
		}
		return mBuckets[bucket];
		}

		unsigned long long LogStatistics::minimum(unsigned short bucket) {
		if (mMinimum[bucket].tv_sec == LONG_MAX) {
		return 0;
		}
		return mMinimum[bucket].nsec();
		}

		void LogStatistics::recordDiff(log_time diff, unsigned short bucket) {
		if ((diff.tv_sec \|\| diff.tv_nsec) && (mMinimum[bucket] > diff)) {
		mMinimum[bucket] = diff;
		}
		}

		void LogStatistics::add(unsigned short size,
		@@ -352,6 +412,9 @@ void LogStatistics::format(char **buf,
		log_id_for_each(i) {
		if (logMask & (1 << i)) {
		oldLength = string.length();
		if (spaces < 0) {
		spaces = 0;
		}
		string.appendFormat("%*s%s", spaces, "", android_log_id_to_name(i));
		spaces += spaces_total + oldLength - string.length();
		}
		@@ -369,6 +432,9 @@ void LogStatistics::format(char **buf,
		continue;
		}
		oldLength = string.length();
		if (spaces < 0) {
		spaces = 0;
		}
		string.appendFormat("%*s%zu/%zu", spaces, "",
		sizesTotal(i), elementsTotal(i));
		spaces += spaces_total + oldLength - string.length();
		@@ -388,12 +454,64 @@ void LogStatistics::format(char **buf,
		size_t els = elements(i);
		if (els) {
		oldLength = string.length();
		if (spaces < 0) {
		spaces = 0;
		}
		string.appendFormat("%*s%zu/%zu", spaces, "", sizes(i), els);
		spaces -= string.length() - oldLength;
		}
		spaces += spaces_total;
		}

		if (dgram_qlen_statistics) {
		const unsigned short spaces_time = 6;
		const unsigned long long max_seconds = 100000;
		spaces = 0;
		string.append("\n\nMinimum time between log events per dgram_qlen:\n");
		for(unsigned short i = 0; dgram_qlen(i); ++i) {
		oldLength = string.length();
		if (spaces < 0) {
		spaces = 0;
		}
		string.appendFormat("%*s%u", spaces, "", dgram_qlen(i));
		spaces += spaces_time + oldLength - string.length();
		}
		string.append("\n");
		spaces = 0;
		unsigned short n;
		for(unsigned short i = 0; (n = dgram_qlen(i)); ++i) {
		unsigned long long duration = minimum(i);
		if (duration) {
		duration /= n;
		if (duration >= (NS_PER_SEC * max_seconds)) {
		duration = NS_PER_SEC * (max_seconds - 1);
		}
		oldLength = string.length();
		if (spaces < 0) {
		spaces = 0;
		}
		string.appendFormat("%*s", spaces, "");
		if (duration >= (NS_PER_SEC * 10)) {
		string.appendFormat("%llu",
		(duration + (NS_PER_SEC / 2))
		/ NS_PER_SEC);
		} else if (duration >= (NS_PER_SEC / (1000 / 10))) {
		string.appendFormat("%llum",
		(duration + (NS_PER_SEC / 2 / 1000))
		/ (NS_PER_SEC / 1000));
		} else if (duration >= (NS_PER_SEC / (1000000 / 10))) {
		string.appendFormat("%lluu",
		(duration + (NS_PER_SEC / 2 / 1000000))
		/ (NS_PER_SEC / 1000000));
		} else {
		string.appendFormat("%llun", duration);
		}
		spaces -= string.length() - oldLength;
		}
		spaces += spaces_time;
		}
		}

		log_id_for_each(i) {
		if (!(logMask & (1 << i))) {
		continue;
		@@ -433,7 +551,7 @@ void LogStatistics::format(char **buf,

		if (!oneline) {
		first = true;
		} else if (!first && spaces) {
		} else if (!first && (spaces > 0)) {
		string.appendFormat("%*s", spaces, "");
		}
		spaces = 0;
		@@ -458,10 +576,16 @@ void LogStatistics::format(char **buf,

		size_t els = up->elements();
		if (els == elsTotal) {
		if (spaces < 0) {
		spaces = 0;
		}
		string.appendFormat("%*s=", spaces, "");
		spaces = -1;
		} else if (els) {
		oldLength = string.length();
		if (spaces < 0) {
		spaces = 0;
		}
		string.appendFormat("%*s%zu/%zu", spaces, "", up->sizes(), els);
		spaces -= string.length() - oldLength;
		}
		@@ -502,7 +626,7 @@ void LogStatistics::format(char **buf,
		continue;
		}

		if (!first && spaces) {
		if (!first && (spaces > 0)) {
		string.appendFormat("%*s", spaces, "");
		}
		spaces = 0;
		@@ -517,10 +641,16 @@ void LogStatistics::format(char **buf,
		spaces += spaces_total + oldLength - string.length();

		if (els == elsTotal) {
		if (spaces < 0) {
		spaces = 0;
		}
		string.appendFormat("%*s=", spaces, "");
		spaces = -1;
		} else if (els) {
		oldLength = string.length();
		if (spaces < 0) {
		spaces = 0;
		}
		string.appendFormat("%*s%zu/%zu", spaces, "",
		pp->sizes(), els);
		spaces -= string.length() - oldLength;
		@@ -531,7 +661,7 @@ void LogStatistics::format(char **buf,
		}

		if (gone_els) {
		if (!first && spaces) {
		if (!first && (spaces > 0)) {
		string.appendFormat("%*s", spaces, "");
		}

logd/LogStatistics.h

+10 −0

Original line number	Diff line number	Diff line
		@@ -114,6 +114,11 @@ class LogStatistics {
		size_t mSizes[LOG_ID_MAX];
		size_t mElements[LOG_ID_MAX];

		bool dgram_qlen_statistics;

		static const unsigned short mBuckets[14];
		log_time mMinimum[sizeof(mBuckets) / sizeof(mBuckets[0])];

		public:
		const log_time start;

		@@ -121,6 +126,11 @@ public:

		LidStatistics &id(log_id_t log_id) { return LogIds[log_id]; }

		void enableDgramQlenStatistics() { dgram_qlen_statistics = true; }
		static unsigned short dgram_qlen(unsigned short bucket);
		unsigned long long minimum(unsigned short bucket);
		void recordDiff(log_time diff, unsigned short bucket);

		void add(unsigned short size, log_id_t log_id, uid_t uid, pid_t pid);
		void subtract(unsigned short size, log_id_t log_id, uid_t uid, pid_t pid);

logd/main.cpp

+9 −0

Original line number	Diff line number	Diff line
		@@ -24,9 +24,12 @@
		#include <sys/capability.h>
		#include <sys/stat.h>
		#include <sys/types.h>
		#include <unistd.h>

		#include <linux/prctl.h>

		#include <cutils/properties.h>

		#include "private/android_filesystem_config.h"
		#include "CommandListener.h"
		#include "LogBuffer.h"
		@@ -92,6 +95,12 @@ int main() {

		LogBuffer *logBuf = new LogBuffer(times);

		char dgram_qlen_statistics[PROPERTY_VALUE_MAX];
		property_get("logd.dgram_qlen.statistics", dgram_qlen_statistics, "");
		if (atol(dgram_qlen_statistics)) {
		logBuf->enableDgramQlenStatistics();
		}

		// LogReader listens on /dev/socket/logdr. When a client
		// connects, log entries in the LogBuffer are written to the client.