tools/gator/daemon/PerfGroup.cpp

/**
 * Copyright (C) ARM Limited 2013-2014. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include "PerfGroup.h"

#include <errno.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/syscall.h>
#include <unistd.h>

#include "Buffer.h"
#include "Logging.h"
#include "Monitor.h"
#include "PerfBuffer.h"
#include "SessionData.h"

#define DEFAULT_PEA_ARGS(pea, additionalSampleType) \
	pea.size = sizeof(pea); \
	/* Emit time, read_format below, group leader id, and raw tracepoint info */ \
	pea.sample_type = PERF_SAMPLE_TIME | PERF_SAMPLE_READ | PERF_SAMPLE_IDENTIFIER | additionalSampleType; \
	/* Emit emit value in group format */ \
	pea.read_format = PERF_FORMAT_ID | PERF_FORMAT_GROUP; \
	/* start out disabled */ \
	pea.disabled = 1; \
	/* have a sampling interrupt happen when we cross the wakeup_watermark boundary */ \
	pea.watermark = 1; \
	/* Be conservative in flush size as only one buffer set is monitored */ \
	pea.wakeup_watermark = 3 * BUF_SIZE / 4

static int sys_perf_event_open(struct perf_event_attr *const attr, const pid_t pid, const int cpu, const int group_fd, const unsigned long flags) {
	return syscall(__NR_perf_event_open, attr, pid, cpu, group_fd, flags);
}

PerfGroup::PerfGroup(PerfBuffer *const pb) : mPb(pb) {
	memset(&mAttrs, 0, sizeof(mAttrs));
	memset(&mKeys, -1, sizeof(mKeys));
	memset(&mFds, -1, sizeof(mFds));
}

PerfGroup::~PerfGroup() {
	for (int pos = ARRAY_LENGTH(mFds) - 1; pos >= 0; --pos) {
		if (mFds[pos] >= 0) {
			close(mFds[pos]);
		}
	}
}

bool PerfGroup::add(Buffer *const buffer, const int key, const __u32 type, const __u64 config, const __u64 sample, const __u64 sampleType, const int flags) {
	int i;
	for (i = 0; i < ARRAY_LENGTH(mKeys); ++i) {
		if (mKeys[i] < 0) {
			break;
		}
	}

	if (i >= ARRAY_LENGTH(mKeys)) {
		logg->logMessage("%s(%s:%i): Too many counters", __FUNCTION__, __FILE__, __LINE__);
		return false;
	}

	DEFAULT_PEA_ARGS(mAttrs[i], sampleType);
	mAttrs[i].type = type;
	mAttrs[i].config = config;
	mAttrs[i].sample_period = sample;
	// always be on the CPU but only a group leader can be pinned
	mAttrs[i].pinned = (i == 0 ? 1 : 0);
	mAttrs[i].mmap = (flags & PERF_GROUP_MMAP ? 1 : 0);
	mAttrs[i].comm = (flags & PERF_GROUP_COMM ? 1 : 0);
	mAttrs[i].freq = (flags & PERF_GROUP_FREQ ? 1 : 0);
	mAttrs[i].task = (flags & PERF_GROUP_TASK ? 1 : 0);
	mAttrs[i].sample_id_all = (flags & PERF_GROUP_SAMPLE_ID_ALL ? 1 : 0);

	mKeys[i] = key;

	buffer->pea(&mAttrs[i], key);

	return true;
}

bool PerfGroup::prepareCPU(const int cpu) {
	logg->logMessage("%s(%s:%i): Onlining cpu %i", __FUNCTION__, __FILE__, __LINE__, cpu);

	for (int i = 0; i < ARRAY_LENGTH(mKeys); ++i) {
		if (mKeys[i] < 0) {
			continue;
		}

		const int offset = i * gSessionData->mCores;
		if (mFds[cpu + offset] >= 0) {
			logg->logMessage("%s(%s:%i): cpu already online or not correctly cleaned up", __FUNCTION__, __FILE__, __LINE__);
			return false;
		}

		logg->logMessage("%s(%s:%i): perf_event_open cpu: %i type: %lli config: %lli sample: %lli sample_type: %lli", __FUNCTION__, __FILE__, __LINE__, cpu, (long long)mAttrs[i].type, (long long)mAttrs[i].config, (long long)mAttrs[i].sample_period, (long long)mAttrs[i].sample_type);
		mFds[cpu + offset] = sys_perf_event_open(&mAttrs[i], -1, cpu, i == 0 ? -1 : mFds[cpu], i == 0 ? 0 : PERF_FLAG_FD_OUTPUT);
		if (mFds[cpu + offset] < 0) {
			logg->logMessage("%s(%s:%i): failed %s", __FUNCTION__, __FILE__, __LINE__, strerror(errno));
			continue;
		}

		if (!mPb->useFd(cpu, mFds[cpu + offset], mFds[cpu])) {
			logg->logMessage("%s(%s:%i): PerfBuffer::useFd failed", __FUNCTION__, __FILE__, __LINE__);
			return false;
		}
	}

	return true;
}

int PerfGroup::onlineCPU(const int cpu, const bool start, Buffer *const buffer, Monitor *const monitor) {
	__u64 ids[ARRAY_LENGTH(mKeys)];
	int coreKeys[ARRAY_LENGTH(mKeys)];
	int idCount = 0;

	for (int i = 0; i < ARRAY_LENGTH(mKeys); ++i) {
		const int fd = mFds[cpu + i * gSessionData->mCores];
		if (fd < 0) {
			continue;
		}

		coreKeys[idCount] = mKeys[i];
		if (ioctl(fd, PERF_EVENT_IOC_ID, &ids[idCount]) != 0) {
			logg->logMessage("%s(%s:%i): ioctl failed", __FUNCTION__, __FILE__, __LINE__);
			return false;
		}
		++idCount;
	}

	if (!monitor->add(mFds[cpu])) {
		logg->logMessage("%s(%s:%i): Monitor::add failed", __FUNCTION__, __FILE__, __LINE__);
		return false;
	}

	buffer->keys(idCount, ids, coreKeys);

	if (start) {
		for (int i = 0; i < ARRAY_LENGTH(mKeys); ++i) {
			int offset = i * gSessionData->mCores + cpu;
			if (mFds[offset] >= 0 && ioctl(mFds[offset], PERF_EVENT_IOC_ENABLE) < 0) {
				logg->logMessage("%s(%s:%i): ioctl failed", __FUNCTION__, __FILE__, __LINE__);
				return false;
			}
		}
	}

	return idCount;
}

bool PerfGroup::offlineCPU(const int cpu) {
	logg->logMessage("%s(%s:%i): Offlining cpu %i", __FUNCTION__, __FILE__, __LINE__, cpu);

	for (int i = 0; i < ARRAY_LENGTH(mKeys); ++i) {
		int offset = i * gSessionData->mCores + cpu;
		if (mFds[offset] >= 0 && ioctl(mFds[offset], PERF_EVENT_IOC_DISABLE) < 0) {
			logg->logMessage("%s(%s:%i): ioctl failed", __FUNCTION__, __FILE__, __LINE__);
			return false;
		}
	}

	// Mark the buffer so that it will be released next time it's read
	mPb->discard(cpu);

	for (int i = 0; i < ARRAY_LENGTH(mKeys); ++i) {
		if (mKeys[i] < 0) {
			continue;
		}

		int offset = i * gSessionData->mCores + cpu;
		if (mFds[offset] >= 0) {
			close(mFds[offset]);
			mFds[offset] = -1;
		}
	}

	return true;
}

bool PerfGroup::start() {
	for (int pos = 0; pos < ARRAY_LENGTH(mFds); ++pos) {
		if (mFds[pos] >= 0 && ioctl(mFds[pos], PERF_EVENT_IOC_ENABLE) < 0) {
			logg->logMessage("%s(%s:%i): ioctl failed", __FUNCTION__, __FILE__, __LINE__);
			goto fail;
		}
	}

	return true;

 fail:
	stop();

	return false;
}

void PerfGroup::stop() {
	for (int pos = ARRAY_LENGTH(mFds) - 1; pos >= 0; --pos) {
		if (mFds[pos] >= 0) {
			ioctl(mFds[pos], PERF_EVENT_IOC_DISABLE);
		}
	}
}