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/**
* Copyright (C) ARM Limited 2013-2016. 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 "PerfBuffer.h"
#include <sys/ioctl.h>
#include <sys/mman.h>
#include "Buffer.h"
#include "Logging.h"
#include "Sender.h"
#include "SessionData.h"
PerfBuffer::PerfBuffer() {
for (int cpu = 0; cpu < ARRAY_LENGTH(mBuf); ++cpu) {
mBuf[cpu] = MAP_FAILED;
mDiscard[cpu] = false;
mFds[cpu] = -1;
}
}
PerfBuffer::~PerfBuffer() {
for (int cpu = ARRAY_LENGTH(mBuf) - 1; cpu >= 0; --cpu) {
if (mBuf[cpu] != MAP_FAILED) {
munmap(mBuf[cpu], gSessionData.mPageSize + BUF_SIZE);
}
}
}
bool PerfBuffer::useFd(const int cpu, const int fd) {
if (mFds[cpu] < 0) {
if (mBuf[cpu] != MAP_FAILED) {
logg.logMessage("cpu %i already online or not correctly cleaned up", cpu);
return false;
}
// The buffer isn't mapped yet
mBuf[cpu] = mmap(NULL, gSessionData.mPageSize + BUF_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
if (mBuf[cpu] == MAP_FAILED) {
logg.logMessage("mmap failed");
return false;
}
mFds[cpu] = fd;
// Check the version
struct perf_event_mmap_page *pemp = static_cast<struct perf_event_mmap_page *>(mBuf[cpu]);
if (pemp->compat_version != 0) {
logg.logMessage("Incompatible perf_event_mmap_page compat_version");
return false;
}
} else {
if (mBuf[cpu] == MAP_FAILED) {
logg.logMessage("cpu already online or not correctly cleaned up");
return false;
}
if (ioctl(fd, PERF_EVENT_IOC_SET_OUTPUT, mFds[cpu]) < 0) {
logg.logMessage("ioctl failed");
return false;
}
}
return true;
}
void PerfBuffer::discard(const int cpu) {
if (mBuf[cpu] != MAP_FAILED) {
mDiscard[cpu] = true;
}
}
bool PerfBuffer::isEmpty() {
for (int cpu = 0; cpu < gSessionData.mCores; ++cpu) {
if (mBuf[cpu] != MAP_FAILED) {
// Take a snapshot of the positions
struct perf_event_mmap_page *pemp = static_cast<struct perf_event_mmap_page *>(mBuf[cpu]);
const __u64 head = ACCESS_ONCE(pemp->data_head);
const __u64 tail = ACCESS_ONCE(pemp->data_tail);
if (head != tail) {
return false;
}
}
}
return true;
}
bool PerfBuffer::isFull() {
for (int cpu = 0; cpu < gSessionData.mCores; ++cpu) {
if (mBuf[cpu] != MAP_FAILED) {
// Take a snapshot of the positions
struct perf_event_mmap_page *pemp = static_cast<struct perf_event_mmap_page *>(mBuf[cpu]);
const __u64 head = ACCESS_ONCE(pemp->data_head);
if (head + 2000 <= (unsigned int)BUF_SIZE) {
return true;
}
}
}
return false;
}
class PerfFrame {
public:
PerfFrame(Sender *const sender) : mSender(sender), mWritePos(-1), mCpuSizePos(-1) {}
void add(const int cpu, const __u64 head, __u64 tail, const uint8_t *const b) {
cpuHeader(cpu);
while (head > tail) {
const int count = reinterpret_cast<const struct perf_event_header *>(b + (tail & BUF_MASK))->size/sizeof(uint64_t);
// Can this whole message be written as Streamline assumes events are not split between frames
if (sizeof(mBuf) <= mWritePos + count*Buffer::MAXSIZE_PACK64) {
send();
cpuHeader(cpu);
}
for (int i = 0; i < count; ++i) {
// Must account for message size
Buffer::packInt64(mBuf, sizeof(mBuf), mWritePos, *reinterpret_cast<const uint64_t *>(b + (tail & BUF_MASK)));
tail += sizeof(uint64_t);
}
}
}
void send() {
if (mWritePos > 0) {
writeFrameSize();
mSender->writeData(mBuf, mWritePos, RESPONSE_APC_DATA);
mWritePos = -1;
mCpuSizePos = -1;
}
}
private:
void writeFrameSize() {
writeCpuSize();
const int typeLength = gSessionData.mLocalCapture ? 0 : 1;
Buffer::writeLEInt(reinterpret_cast<unsigned char *>(mBuf + typeLength), mWritePos - typeLength - sizeof(uint32_t));
}
void frameHeader() {
if (mWritePos < 0) {
mWritePos = 0;
mCpuSizePos = -1;
if (!gSessionData.mLocalCapture) {
mBuf[mWritePos++] = RESPONSE_APC_DATA;
}
// Reserve space for frame size
mWritePos += sizeof(uint32_t);
Buffer::packInt(mBuf, sizeof(mBuf), mWritePos, FRAME_PERF);
}
}
void writeCpuSize() {
if (mCpuSizePos >= 0) {
Buffer::writeLEInt(reinterpret_cast<unsigned char *>(mBuf + mCpuSizePos), mWritePos - mCpuSizePos - sizeof(uint32_t));
}
}
void cpuHeader(const int cpu) {
if (sizeof(mBuf) <= mWritePos + Buffer::MAXSIZE_PACK32 + sizeof(uint32_t)) {
send();
}
frameHeader();
writeCpuSize();
Buffer::packInt(mBuf, sizeof(mBuf), mWritePos, cpu);
mCpuSizePos = mWritePos;
// Reserve space for cpu size
mWritePos += sizeof(uint32_t);
}
// Pick a big size but something smaller than the chunkSize in Sender::writeData which is 100k
char mBuf[1<<16];
Sender *const mSender;
int mWritePos;
int mCpuSizePos;
// Intentionally unimplemented
PerfFrame(const PerfFrame &);
PerfFrame& operator=(const PerfFrame &);
};
bool PerfBuffer::send(Sender *const sender) {
PerfFrame frame(sender);
for (int cpu = 0; cpu < gSessionData.mCores; ++cpu) {
if (mBuf[cpu] == MAP_FAILED) {
continue;
}
// Take a snapshot of the positions
struct perf_event_mmap_page *pemp = static_cast<struct perf_event_mmap_page *>(mBuf[cpu]);
const __u64 head = ACCESS_ONCE(pemp->data_head);
const __u64 tail = ACCESS_ONCE(pemp->data_tail);
if (head > tail) {
const uint8_t *const b = static_cast<uint8_t *>(mBuf[cpu]) + gSessionData.mPageSize;
frame.add(cpu, head, tail, b);
// Update tail with the data read
pemp->data_tail = head;
}
if (mDiscard[cpu]) {
munmap(mBuf[cpu], gSessionData.mPageSize + BUF_SIZE);
mBuf[cpu] = MAP_FAILED;
mDiscard[cpu] = false;
mFds[cpu] = -1;
logg.logMessage("Unmaped cpu %i", cpu);
}
}
frame.send();
return true;
}
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