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/**
* 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 "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("%s(%s:%i): cpu %i already online or not correctly cleaned up", __FUNCTION__, __FILE__, __LINE__, 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("%s(%s:%i): mmap failed", __FUNCTION__, __FILE__, __LINE__);
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("%s(%s:%i): Incompatible perf_event_mmap_page compat_version", __FUNCTION__, __FILE__, __LINE__);
return false;
}
} else {
if (mBuf[cpu] == MAP_FAILED) {
logg->logMessage("%s(%s:%i): cpu already online or not correctly cleaned up", __FUNCTION__, __FILE__, __LINE__);
return false;
}
if (ioctl(fd, PERF_EVENT_IOC_SET_OUTPUT, mFds[cpu]) < 0) {
logg->logMessage("%s(%s:%i): ioctl failed", __FUNCTION__, __FILE__, __LINE__);
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 = pemp->data_head;
const __u64 tail = pemp->data_tail;
if (head != tail) {
return false;
}
}
}
return true;
}
static void compressAndSend(const int cpu, const __u64 head, __u64 tail, const uint8_t *const b, Sender *const sender) {
// Pick a big size but something smaller than the chunkSize in Sender::writeData which is 100k
char buf[1<<16];
int writePos = 0;
const int typeLength = gSessionData->mLocalCapture ? 0 : 1;
while (head > tail) {
writePos = 0;
if (!gSessionData->mLocalCapture) {
buf[writePos++] = RESPONSE_APC_DATA;
}
// Reserve space for size
writePos += sizeof(uint32_t);
Buffer::packInt(buf, sizeof(buf), writePos, FRAME_PERF);
Buffer::packInt(buf, sizeof(buf), writePos, 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(buf) <= writePos + count*Buffer::MAXSIZE_PACK64) {
break;
}
for (int i = 0; i < count; ++i) {
// Must account for message size
Buffer::packInt64(buf, sizeof(buf), writePos, *reinterpret_cast<const uint64_t *>(b + (tail & BUF_MASK)));
tail += sizeof(uint64_t);
}
}
// Write size
Buffer::writeLEInt(reinterpret_cast<unsigned char *>(buf + typeLength), writePos - typeLength - sizeof(uint32_t));
sender->writeData(buf, writePos, RESPONSE_APC_DATA);
}
}
bool PerfBuffer::send(Sender *const 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 = pemp->data_head;
const __u64 tail = pemp->data_tail;
if (head > tail) {
const uint8_t *const b = static_cast<uint8_t *>(mBuf[cpu]) + gSessionData->mPageSize;
compressAndSend(cpu, head, tail, b, sender);
// 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("%s(%s:%i): Unmaped cpu %i", __FUNCTION__, __FILE__, __LINE__, cpu);
}
}
return true;
}
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