diff options
Diffstat (limited to 'drivers/gator/daemon/Collector.cpp')
| -rw-r--r-- | drivers/gator/daemon/Collector.cpp | 281 |
1 files changed, 281 insertions, 0 deletions
diff --git a/drivers/gator/daemon/Collector.cpp b/drivers/gator/daemon/Collector.cpp new file mode 100644 index 00000000000..7a41198e5cb --- /dev/null +++ b/drivers/gator/daemon/Collector.cpp @@ -0,0 +1,281 @@ +/** + * 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 <fcntl.h> +#include <malloc.h> +#include <unistd.h> +#include <string.h> +#include <stdlib.h> +#include <errno.h> +#include <sys/time.h> +#include "Collector.h" +#include "SessionData.h" +#include "Logging.h" + +extern void handleException(); + +// Driver initialization independent of session settings +Collector::Collector() { + char text[sizeof(gSessionData->mPerfCounterType[0]) + 20]; // sufficiently large to hold all events/<types>/<file> + + bufferFD = 0; + + checkVersion(); + + int enable = -1; + if (readIntDriver("enable", &enable) != 0 || enable != 0) { + logg->logError(__FILE__, __LINE__, "Driver already enabled, possibly a session is already in progress."); + handleException(); + } + + readIntDriver("cpu_cores", &gSessionData->mCores); + if (gSessionData->mCores == 0) { + gSessionData->mCores = 1; + } + + bufferSize = 512 * 1024; + if (writeReadDriver("buffer_size", &bufferSize) || bufferSize <= 0) { + logg->logError(__FILE__, __LINE__, "Unable to set 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), "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("enable", "0"); + + // Calls event_buffer_release in the driver + if (bufferFD) { + close(bufferFD); + } +} + +void Collector::enablePerfCounters() { + char text[sizeof(gSessionData->mPerfCounterType[0]) + 30]; // sufficiently large to hold all /dev/gator/events/<types>/enabled + for (int i=0; i<MAX_PERFORMANCE_COUNTERS; i++) { + if (!gSessionData->mPerfCounterEnabled[i]) { + continue; + } + snprintf(text, sizeof(text), "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]) + 10]; // sufficiently large to hold all events/<types> + char text[sizeof(gSessionData->mPerfCounterType[0]) + 20]; // sufficiently large to hold all events/<types>/<file> + + for (int i=0; i<MAX_PERFORMANCE_COUNTERS; i++) { + if (!gSessionData->mPerfCounterEnabled[i]) { + continue; + } + snprintf(base, sizeof(base), "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(resolvePath(text), F_OK) == 0) { + if (writeReadDriver(text, &gSessionData->mPerfCounterCount[i]) && gSessionData->mPerfCounterCount[i] > 0) { + logg->logError(__FILE__, __LINE__, "Cannot enable EBS for %s with a count of %d\n", 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("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("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 + bufferFD = open(resolvePath("buffer"), O_RDONLY); + if (bufferFD < 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("tick", &gSessionData->mSampleRate) != 0) { + logg->logError(__FILE__, __LINE__, "Unable to set the driver tick"); + handleException(); + } + + // notify the kernel of the streaming mode, currently used for network stats + int streaming = (int)!gSessionData->mOneShot; + if (writeReadDriver("streaming", &streaming) != 0) { + logg->logError(__FILE__, __LINE__, "Unable to set streaming"); + handleException(); + } + + logg->logMessage("Start the driver"); + + // This command makes the driver start profiling by calling gator_op_start() in the driver + if (writeDriver("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(bufferFD, 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("enable", "0") != 0) { + logg->logMessage("Stopping kernel failed"); + } +} + +int Collector::collect(char* buffer) { + // Calls event_buffer_read in the driver + int bytesRead = read(bufferFD, buffer, bufferSize); + + // 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(bufferFD, buffer, bufferSize); + } + + 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 *)((int)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); +} + +char* Collector::resolvePath(const char* file) { + static char fullpath[100]; // Sufficiently large to hold any path within /dev/gator + snprintf(fullpath, sizeof(fullpath), "/dev/gator/%s", file); + return fullpath; +} + +int Collector::readIntDriver(const char* path, int* value) { + char* fullpath = resolvePath(path); + 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* path, const char* data) { + char* fullpath = resolvePath(path); + 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; +} |