/** * Copyright (C) ARM Limited 2010-2012. 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 #include #include #include #include #include #include #include "Collector.h" #include "SessionData.h" #include "Logging.h" #include "Sender.h" // Driver initialization independent of session settings Collector::Collector() { char text[sizeof(gSessionData->mPerfCounterType[0]) + 30]; // sufficiently large to hold all /dev/gator/events// mBufferFD = 0; checkVersion(); int enable = -1; if (readIntDriver("/dev/gator/enable", &enable) != 0 || enable != 0) { logg->logError(__FILE__, __LINE__, "Driver already enabled, possibly a session is already in progress."); handleException(); } readIntDriver("/dev/gator/cpu_cores", &gSessionData->mCores); if (gSessionData->mCores == 0) { gSessionData->mCores = 1; } mBufferSize = 0; if (readIntDriver("/dev/gator/buffer_size", &mBufferSize) || mBufferSize <= 0) { logg->logError(__FILE__, __LINE__, "Unable to read the driver buffer size"); handleException(); } getCoreName(); enablePerfCounters(); // Read unchanging keys from driver which are created at insmod'ing of gator.ko for (int i = 0; i < MAX_PERFORMANCE_COUNTERS; i++) { if (gSessionData->mPerfCounterEnabled[i]) { snprintf(text, sizeof(text), "/dev/gator/events/%s/key", gSessionData->mPerfCounterType[i]); readIntDriver(text, &gSessionData->mPerfCounterKey[i]); } } } Collector::~Collector() { // Write zero for safety, as a zero should have already been written writeDriver("/dev/gator/enable", "0"); // Calls event_buffer_release in the driver if (mBufferFD) { close(mBufferFD); } } #include void Collector::enablePerfCounters() { char text[sizeof(gSessionData->mPerfCounterType[0]) + 30]; // sufficiently large to hold all /dev/gator/events//enabled // Initialize all perf counters in the driver, i.e. set enabled to zero struct dirent *ent; DIR* dir = opendir("/dev/gator/events"); if (dir) { while ((ent = readdir(dir)) != NULL) { // skip hidden files, current dir, and parent dir if (ent->d_name[0] == '.') continue; snprintf(text, sizeof(text), "/dev/gator/events/%s/enabled", ent->d_name); writeDriver(text, 0); } closedir (dir); } for (int i=0; imPerfCounterEnabled[i]) { continue; } snprintf(text, sizeof(text), "/dev/gator/events/%s/enabled", gSessionData->mPerfCounterType[i]); if (writeReadDriver(text, &gSessionData->mPerfCounterEnabled[i])) { // Disable those events that don't exist on this hardware platform even though they exist in configuration.xml gSessionData->mPerfCounterEnabled[i] = 0; continue; } } } void Collector::setupPerfCounters() { char base[sizeof(gSessionData->mPerfCounterType[0]) + 20]; // sufficiently large to hold all /dev/gator/events/ char text[sizeof(gSessionData->mPerfCounterType[0]) + 30]; // sufficiently large to hold all /dev/gator/events// for (int i=0; imPerfCounterEnabled[i]) { continue; } snprintf(base, sizeof(base), "/dev/gator/events/%s", gSessionData->mPerfCounterType[i]); snprintf(text, sizeof(text), "%s/event", base); writeDriver(text, gSessionData->mPerfCounterEvent[i]); if (gSessionData->mPerfCounterEBSCapable[i]) { snprintf(text, sizeof(text), "%s/count", base); if (access(text, F_OK) == 0) { if (writeReadDriver(text, &gSessionData->mPerfCounterCount[i]) && gSessionData->mPerfCounterCount[i] > 0) { logg->logError(__FILE__, __LINE__, "Cannot enable EBS for %s:%s with a count of %d\n", gSessionData->mPerfCounterTitle[i], gSessionData->mPerfCounterName[i], gSessionData->mPerfCounterCount[i]); handleException(); } } else if (gSessionData->mPerfCounterCount[i] > 0) { logg->logError(__FILE__, __LINE__, "Event Based Sampling is only supported with kernel versions 3.0.0 and higher with CONFIG_PERF_EVENTS=y, and CONFIG_HW_PERF_EVENTS=y\n"); handleException(); } } } } void Collector::checkVersion() { int driver_version = 0; if (readIntDriver("/dev/gator/version", &driver_version) == -1) { logg->logError(__FILE__, __LINE__, "Error reading gator driver version"); handleException(); } // Verify the driver version matches the daemon version if (driver_version != PROTOCOL_VERSION) { if ((driver_version > PROTOCOL_DEV) || (PROTOCOL_VERSION > PROTOCOL_DEV)) { // One of the mismatched versions is development version logg->logError(__FILE__, __LINE__, "DEVELOPMENT BUILD MISMATCH: gator driver version \"%d\" is not in sync with gator daemon version \"%d\".\n" ">> The following must be synchronized from engineering repository:\n" ">> * gator driver\n" ">> * gator daemon\n" ">> * Streamline", driver_version, PROTOCOL_VERSION); handleException(); } else { // Release version mismatch logg->logError(__FILE__, __LINE__, "gator driver version \"%d\" is different than gator daemon version \"%d\".\n" ">> Please upgrade the driver and daemon to the latest versions.", driver_version, PROTOCOL_VERSION); handleException(); } } } void Collector::start() { // Set the maximum backtrace depth if (writeReadDriver("/dev/gator/backtrace_depth", &gSessionData->mBacktraceDepth)) { logg->logError(__FILE__, __LINE__, "Unable to set the driver backtrace depth"); handleException(); } // open the buffer which calls userspace_buffer_open() in the driver mBufferFD = open("/dev/gator/buffer", O_RDONLY); if (mBufferFD < 0) { logg->logError(__FILE__, __LINE__, "The gator driver did not set up properly. Please view the linux console or dmesg log for more information on the failure."); handleException(); } // set the tick rate of the profiling timer if (writeReadDriver("/dev/gator/tick", &gSessionData->mSampleRate) != 0) { logg->logError(__FILE__, __LINE__, "Unable to set the driver tick"); handleException(); } // notify the kernel of the response type int response_type = gSessionData->mLocalCapture ? 0 : RESPONSE_APC_DATA; if (writeDriver("/dev/gator/response_type", response_type)) { logg->logError(__FILE__, __LINE__, "Unable to write the response type"); handleException(); } logg->logMessage("Start the driver"); // This command makes the driver start profiling by calling gator_op_start() in the driver if (writeDriver("/dev/gator/enable", "1") != 0) { logg->logError(__FILE__, __LINE__, "The gator driver did not start properly. Please view the linux console or dmesg log for more information on the failure."); handleException(); } lseek(mBufferFD, 0, SEEK_SET); } // These commands should cause the read() function in collect() to return void Collector::stop() { // This will stop the driver from profiling if (writeDriver("/dev/gator/enable", "0") != 0) { logg->logMessage("Stopping kernel failed"); } } int Collector::collect(char* buffer) { // Calls event_buffer_read in the driver int bytesRead; errno = 0; bytesRead = read(mBufferFD, buffer, mBufferSize); // If read() returned due to an interrupt signal, re-read to obtain the last bit of collected data if (bytesRead == -1 && errno == EINTR) { bytesRead = read(mBufferFD, buffer, mBufferSize); } // return the total bytes written logg->logMessage("Driver read of %d bytes", bytesRead); return bytesRead; } void Collector::getCoreName() { char temp[256]; // arbitrarily large amount strcpy(gSessionData->mCoreName, "unknown"); FILE* f = fopen("/proc/cpuinfo", "r"); if (f == NULL) { logg->logMessage("Error opening /proc/cpuinfo\n" "The core name in the captured xml file will be 'unknown'."); return; } while (fgets(temp, sizeof(temp), f)) { if (strlen(temp) > 0) { temp[strlen(temp) - 1] = 0; // Replace the line feed with a null } if (strstr(temp, "Hardware") != 0) { char* position = strchr(temp, ':'); if (position == NULL || (unsigned int)(position - temp) + 2 >= strlen(temp)) { logg->logMessage("Unknown format of /proc/cpuinfo\n" "The core name in the captured xml file will be 'unknown'."); return; } strncpy(gSessionData->mCoreName, (char*)((long)position + 2), sizeof(gSessionData->mCoreName)); gSessionData->mCoreName[sizeof(gSessionData->mCoreName) - 1] = 0; // strncpy does not guarantee a null-terminated string fclose(f); return; } } logg->logMessage("Could not determine core name from /proc/cpuinfo\n" "The core name in the captured xml file will be 'unknown'."); fclose(f); } int Collector::readIntDriver(const char* fullpath, int* value) { FILE* file = fopen(fullpath, "r"); if (file == NULL) { return -1; } if (fscanf(file, "%u", value) != 1) { fclose(file); logg->logMessage("Invalid value in file %s", fullpath); return -1; } fclose(file); return 0; } int Collector::writeDriver(const char* path, int value) { char data[40]; // Sufficiently large to hold any integer snprintf(data, sizeof(data), "%d", value); return writeDriver(path, data); } int Collector::writeDriver(const char* fullpath, const char* data) { int fd = open(fullpath, O_WRONLY); if (fd < 0) { return -1; } if (write(fd, data, strlen(data)) < 0) { close(fd); logg->logMessage("Opened but could not write to %s", fullpath); return -1; } close(fd); return 0; } int Collector::writeReadDriver(const char* path, int* value) { if (writeDriver(path, *value) || readIntDriver(path, value)) { return -1; } return 0; }