EnvVars.hpp

/*
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*/

#ifndef ENVVARS_HPP
#define ENVVARS_HPP

#include <algorithm>

#define TB_VERSION "1.02"

// This class manages environment variable that affect TransferBench
class EnvVars
{
public:
  // Default configuration values
  int const DEFAULT_NUM_WARMUPS          =  3;
  int const DEFAULT_NUM_ITERATIONS       = 10;
  int const DEFAULT_SAMPLING_FACTOR      =  1;
  int const DEFAULT_NUM_CPU_PER_TRANSFER =  4;

  // Environment variables
  int blockBytes;        // Each CU, except the last, gets a multiple of this many bytes to copy
  int byteOffset;        // Byte-offset for memory allocations
  int numCpuPerTransfer; // Number of CPU child threads to use per CPU Transfer
  int numIterations;     // Number of timed iterations to perform.  If negative, run for -numIterations seconds instead
  int numWarmups;        // Number of un-timed warmup iterations to perform
  int outputToCsv;       // Output in CSV format
  int samplingFactor;    // Affects how many different values of N are generated (when N set to 0)
  int sharedMemBytes;    // Amount of shared memory to use per threadblock
  int useHipCall;        // Use hipMemcpy/hipMemset instead of custom shader kernels
  int useInteractive;    // Pause for user-input before starting transfer loop
  int useMemset;         // Perform a memset instead of a copy (ignores source memory)
  int usePcieIndexing;   // Base GPU indexing on PCIe address instead of HIP device
  int useSingleStream;   // Use a single stream per device instead of per Tink. Can not be used with USE_HIP_CALL

  std::vector<float> fillPattern; // Pattern of floats used to fill source data

  // Constructor that collects values
  EnvVars()
  {
    int maxSharedMemBytes = 0;
    hipDeviceGetAttribute(&maxSharedMemBytes,
                          hipDeviceAttributeMaxSharedMemoryPerMultiprocessor, 0);

    blockBytes        = GetEnvVar("BLOCK_BYTES"         , 256);
    byteOffset        = GetEnvVar("BYTE_OFFSET"         , 0);
    numCpuPerTransfer = GetEnvVar("NUM_CPU_PER_TRANSFER", DEFAULT_NUM_CPU_PER_TRANSFER);
    numIterations     = GetEnvVar("NUM_ITERATIONS"      , DEFAULT_NUM_ITERATIONS);
    numWarmups        = GetEnvVar("NUM_WARMUPS"         , DEFAULT_NUM_WARMUPS);
    outputToCsv       = GetEnvVar("OUTPUT_TO_CSV"       , 0);
    samplingFactor    = GetEnvVar("SAMPLING_FACTOR"     , DEFAULT_SAMPLING_FACTOR);
    sharedMemBytes    = GetEnvVar("SHARED_MEM_BYTES"    , maxSharedMemBytes / 2 + 1);
    useHipCall        = GetEnvVar("USE_HIP_CALL"        , 0);
    useInteractive    = GetEnvVar("USE_INTERACTIVE"     , 0);
    useMemset         = GetEnvVar("USE_MEMSET"          , 0);
    usePcieIndexing   = GetEnvVar("USE_PCIE_INDEX"      , 0);
    useSingleStream   = GetEnvVar("USE_SINGLE_STREAM"   , 0);

    // Check for fill pattern
    char* pattern = getenv("FILL_PATTERN");
    if (pattern != NULL)
    {
      int patternLen = strlen(pattern);
      if (patternLen % 2)
      {
        printf("[ERROR] FILL_PATTERN must contain an even-number of hex digits\n");
        exit(1);
      }

      // Read in bytes
      std::vector<unsigned char> bytes;
      unsigned char val = 0;
      for (int i = 0; i < patternLen; i++)
      {
        if ('0' <= pattern[i] && pattern[i] <= '9')
          val += (pattern[i] - '0');
        else if ('A' <= pattern[i] && pattern[i] <= 'F')
          val += (pattern[i] - 'A' + 10);
        else if ('a' <= pattern[i] && pattern[i] <= 'f')
          val += (pattern[i] - 'a' + 10);
        else
        {
          printf("[ERROR] FILL_PATTERN must contain an even-number of hex digits (0-9'/a-f/A-F).  (not %c)\n", pattern[i]);
          exit(1);
        }

        if (i % 2 == 0)
          val <<= 4;
        else
        {
          bytes.push_back(val);
          val = 0;
        }
      }

      // Reverse bytes (input is assumed to be given in big-endian)
      std::reverse(bytes.begin(), bytes.end());

      // Figure out how many copies of the pattern are necessary to fill a 4-byte float properly
      int copies;
      switch (patternLen % 8)
      {
      case 0:  copies = 1; break;
      case 4:  copies = 2; break;
      default: copies = 4; break;
      }

      // Fill floats
      int numFloats = copies * patternLen / 8;
      fillPattern.resize(numFloats);
      unsigned char* rawData = (unsigned char*) fillPattern.data();
      for (int i = 0; i < numFloats * 4; i++)
        rawData[i] = bytes[i % bytes.size()];
    }
    else fillPattern.clear();

    // Perform some basic validation
    if (byteOffset % sizeof(float))
    {
      printf("[ERROR] BYTE_OFFSET must be set to multiple of %lu\n", sizeof(float));
      exit(1);
    }
    if (numWarmups < 0)
    {
      printf("[ERROR] NUM_WARMUPS must be set to a non-negative number\n");
      exit(1);
    }
    if (samplingFactor < 1)
    {
      printf("[ERROR] SAMPLING_FACTOR must be greater or equal to 1\n");
      exit(1);
    }
    if (numCpuPerTransfer < 1)
    {
      printf("[ERROR] NUM_CPU_PER_TRANSFER must be greater or equal to 1\n");
      exit(1);
    }
    if (sharedMemBytes < 0 || sharedMemBytes > maxSharedMemBytes)
    {
      printf("[ERROR] SHARED_MEM_BYTES must be between 0 and %d\n", maxSharedMemBytes);
      exit(1);
    }
    if (blockBytes <= 0 || blockBytes % 4)
    {
      printf("[ERROR] BLOCK_BYTES must be a positive multiple of 4\n");
      exit(1);
    }
    if (useSingleStream && useHipCall)
    {
      printf("[ERROR] Single stream mode cannot be used with HIP calls\n");
      exit(1);
    }
  }

  // Display info on the env vars that can be used
  static void DisplayUsage()
  {
    printf("Environment variables:\n");
    printf("======================\n");
    printf(" BLOCK_BYTES=B      - Each CU (except the last) receives a multiple of BLOCK_BYTES to copy\n");
    printf(" BYTE_OFFSET        - Initial byte-offset for memory allocations.  Must be multiple of 4. Defaults to 0\n");
    printf(" FILL_PATTERN=STR   - Fill input buffer with pattern specified in hex digits (0-9,a-f,A-F).  Must be even number of digits, (byte-level big-endian)\n");
    printf(" NUM_CPU_PER_TRANSFER=C - Use C threads per Transfer for CPU-executed copies\n");
    printf(" NUM_ITERATIONS=I   - Perform I timed iteration(s) per test\n");
    printf(" NUM_WARMUPS=W      - Perform W untimed warmup iteration(s) per test\n");
    printf(" OUTPUT_TO_CSV      - Outputs to CSV format if set\n");
    printf(" SAMPLING_FACTOR=F  - Add F samples (when possible) between powers of 2 when auto-generating data sizes\n");
    printf(" SHARED_MEM_BYTES=X - Use X shared mem bytes per threadblock, potentially to avoid multiple threadblocks per CU\n");
    printf(" USE_HIP_CALL       - Use hipMemcpy/hipMemset instead of custom shader kernels for GPU-executed copies\n");
    printf(" USE_INTERACTIVE    - Pause for user-input before starting transfer loop\n");
    printf(" USE_MEMSET         - Perform a memset instead of a copy (ignores source memory)\n");
    printf(" USE_PCIE_INDEX     - Index GPUs by PCIe address-ordering instead of HIP-provided indexing\n");
    printf(" USE_SINGLE_STREAM  - Use single stream per device instead of per Transfer.  Cannot be used with USE_HIP_CALL\n");
  }

  // Display env var settings
  void DisplayEnvVars() const
  {
    if (!outputToCsv)
    {
      printf("Run configuration (TransferBench v%s)\n", TB_VERSION);
      printf("=====================================================\n");
      printf("%-20s = %12d : Each CU gets a multiple of %d bytes to copy\n", "BLOCK_BYTES", blockBytes, blockBytes);
      printf("%-20s = %12d : Using byte offset of %d\n", "BYTE_OFFSET", byteOffset, byteOffset);
      printf("%-20s = %12s : ", "FILL_PATTERN", getenv("FILL_PATTERN") ? "(specified)" : "(unset)");
      if (fillPattern.size())
        printf("Pattern: %s", getenv("FILL_PATTERN"));
      else
        printf("Pseudo-random: (Element i = i modulo 383 + 31)");
      printf("\n");
      printf("%-20s = %12d : Using %d CPU thread(s) per CPU-based-copy Transfer\n", "NUM_CPU_PER_TRANSFER", numCpuPerTransfer, numCpuPerTransfer);
      printf("%-20s = %12d : Running %d %s per topology\n", "NUM_ITERATIONS", numIterations,
             numIterations > 0 ? numIterations : -numIterations,
             numIterations > 0 ? "timed iteration(s)" : "second(s)");
      printf("%-20s = %12d : Running %d warmup iteration(s) per topology\n", "NUM_WARMUPS", numWarmups, numWarmups);
      printf("%-20s = %12d : Output to %s\n", "OUTPUT_TO_CSV", outputToCsv,
             outputToCsv ? "CSV" : "console");
      printf("%-20s = %12s : Using %d shared mem per threadblock\n", "SHARED_MEM_BYTES",
             getenv("SHARED_MEM_BYTES") ? "(specified)" : "(unset)", sharedMemBytes);
      printf("%-20s = %12d : Using %s for GPU-executed copies\n", "USE_HIP_CALL", useHipCall,
             useHipCall ? "HIP functions" : "custom kernels");
      if (useHipCall && !useMemset)
      {
        char* env = getenv("HSA_ENABLE_SDMA");
        printf("%-20s = %12s : %s\n", "HSA_ENABLE_SDMA", env,
               (env && !strcmp(env, "0")) ? "Using blit kernels for hipMemcpy" : "Using DMA copy engines");
      }
      printf("%-20s = %12d : Running in %s mode\n", "USE_INTERACTIVE", useInteractive,
             useInteractive ? "interactive" : "non-interactive");
      printf("%-20s = %12d : Performing %s\n", "USE_MEMSET", useMemset,
             useMemset ? "memset" : "memcopy");
      printf("%-20s = %12d : Using %s-based GPU indexing\n", "USE_PCIE_INDEX",
             usePcieIndexing, (usePcieIndexing ? "PCIe" : "HIP"));
      printf("%-20s = %12d : Using single stream per %s\n", "USE_SINGLE_STREAM",
             useSingleStream, (useSingleStream ? "device" : "Transfer"));
      printf("\n");
    }
  };

  // Helper function that gets parses environment variable or sets to default value
  static int GetEnvVar(std::string const varname, int defaultValue)
  {
    if (getenv(varname.c_str()))
      return atoi(getenv(varname.c_str()));
    return defaultValue;
  }
};

#endif