1 | """ |
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2 | GPU driver for C kernels |
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3 | |
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4 | There should be a single GPU environment running on the system. This |
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5 | environment is constructed on the first call to :func:`env`, and the |
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6 | same environment is returned on each call. |
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7 | |
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8 | After retrieving the environment, the next step is to create the kernel. |
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9 | This is done with a call to :meth:`GpuEnvironment.make_kernel`, which |
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10 | returns the type of data used by the kernel. |
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11 | |
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12 | Next a :class:`GpuData` object should be created with the correct kind |
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13 | of data. This data object can be used by multiple kernels, for example, |
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14 | if the target model is a weighted sum of multiple kernels. The data |
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15 | should include any extra evaluation points required to compute the proper |
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16 | data smearing. This need not match the square grid for 2D data if there |
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17 | is an index saying which q points are active. |
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18 | |
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19 | Together the GpuData, the program, and a device form a :class:`GpuKernel`. |
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20 | This kernel is used during fitting, receiving new sets of parameters and |
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21 | evaluating them. The output value is stored in an output buffer on the |
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22 | devices, where it can be combined with other structure factors and form |
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23 | factors and have instrumental resolution effects applied. |
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24 | |
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25 | In order to use OpenCL for your models, you will need OpenCL drivers for |
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26 | your machine. These should be available from your graphics card vendor. |
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27 | Intel provides OpenCL drivers for CPUs as well as their integrated HD |
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28 | graphics chipsets. AMD also provides drivers for Intel CPUs, but as of |
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29 | this writing the performance is lacking compared to the Intel drivers. |
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30 | NVidia combines drivers for CUDA and OpenCL in one package. The result |
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31 | is a bit messy if you have multiple drivers installed. You can see which |
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32 | drivers are available by starting python and running: |
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33 | |
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34 | import pyopencl as cl |
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35 | cl.create_some_context(interactive=True) |
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36 | |
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37 | Once you have done that, it will show the available drivers which you |
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38 | can select. It will then tell you that you can use these drivers |
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39 | automatically by setting the SAS_OPENCL environment variable, which is |
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40 | PYOPENCL_CTX equivalent but not conflicting with other pyopnecl programs. |
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41 | |
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42 | Some graphics cards have multiple devices on the same card. You cannot |
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43 | yet use both of them concurrently to evaluate models, but you can run |
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44 | the program twice using a different device for each session. |
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45 | |
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46 | OpenCL kernels are compiled when needed by the device driver. Some |
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47 | drivers produce compiler output even when there is no error. You |
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48 | can see the output by setting PYOPENCL_COMPILER_OUTPUT=1. It should be |
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49 | harmless, albeit annoying. |
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50 | """ |
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51 | from __future__ import print_function |
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52 | |
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53 | import os |
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54 | import warnings |
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55 | import logging |
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56 | import time |
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57 | |
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58 | import numpy as np # type: ignore |
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59 | |
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60 | |
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61 | # Attempt to setup opencl. This may fail if the opencl package is not |
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62 | # installed or if it is installed but there are no devices available. |
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63 | try: |
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64 | import pycuda.autoinit |
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65 | import pycuda.driver as cuda # type: ignore |
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66 | from pycuda.compiler import SourceModule |
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67 | HAVE_CUDA = True |
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68 | CUDA_ERROR = "" |
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69 | except Exception as exc: |
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70 | HAVE_CUDA = False |
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71 | CUDA_ERROR = str(exc) |
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72 | |
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73 | from . import generate |
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74 | from .kernel import KernelModel, Kernel |
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75 | |
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76 | # pylint: disable=unused-import |
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77 | try: |
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78 | from typing import Tuple, Callable, Any |
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79 | from .modelinfo import ModelInfo |
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80 | from .details import CallDetails |
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81 | except ImportError: |
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82 | pass |
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83 | # pylint: enable=unused-import |
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84 | |
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85 | # The max loops number is limited by the amount of local memory available |
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86 | # on the device. You don't want to make this value too big because it will |
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87 | # waste resources, nor too small because it may interfere with users trying |
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88 | # to do their polydispersity calculations. A value of 1024 should be much |
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89 | # larger than necessary given that cost grows as npts^k where k is the number |
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90 | # of polydisperse parameters. |
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91 | MAX_LOOPS = 2048 |
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92 | |
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93 | |
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94 | # Pragmas for enable OpenCL features. Be sure to protect them so that they |
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95 | # still compile even if OpenCL is not present. |
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96 | _F16_PRAGMA = """\ |
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97 | #if defined(__OPENCL_VERSION__) // && !defined(cl_khr_fp16) |
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98 | # pragma OPENCL EXTENSION cl_khr_fp16: enable |
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99 | #endif |
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100 | """ |
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101 | |
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102 | _F64_PRAGMA = """\ |
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103 | #if defined(__OPENCL_VERSION__) // && !defined(cl_khr_fp64) |
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104 | # pragma OPENCL EXTENSION cl_khr_fp64: enable |
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105 | #endif |
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106 | """ |
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107 | |
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108 | def use_cuda(): |
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109 | return HAVE_CUDA |
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110 | |
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111 | ENV = None |
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112 | def reset_environment(): |
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113 | """ |
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114 | Call to create a new OpenCL context, such as after a change to SAS_OPENCL. |
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115 | """ |
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116 | global ENV |
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117 | ENV = GpuEnvironment() if use_cuda() else None |
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118 | |
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119 | def environment(): |
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120 | # type: () -> "GpuEnvironment" |
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121 | """ |
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122 | Returns a singleton :class:`GpuEnvironment`. |
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123 | |
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124 | This provides an OpenCL context and one queue per device. |
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125 | """ |
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126 | if ENV is None: |
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127 | if not HAVE_CUDA: |
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128 | raise RuntimeError("OpenCL startup failed with ***" |
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129 | + CUDA_ERROR + "***; using C compiler instead") |
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130 | reset_environment() |
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131 | if ENV is None: |
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132 | raise RuntimeError("SAS_OPENCL=None in environment") |
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133 | return ENV |
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134 | |
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135 | def _stretch_input(vector, dtype, extra=1e-3, boundary=32): |
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136 | # type: (np.ndarray, np.dtype, float, int) -> np.ndarray |
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137 | """ |
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138 | Stretch an input vector to the correct boundary. |
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139 | |
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140 | Performance on the kernels can drop by a factor of two or more if the |
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141 | number of values to compute does not fall on a nice power of two |
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142 | boundary. The trailing additional vector elements are given a |
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143 | value of *extra*, and so f(*extra*) will be computed for each of |
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144 | them. The returned array will thus be a subset of the computed array. |
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145 | |
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146 | *boundary* should be a power of 2 which is at least 32 for good |
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147 | performance on current platforms (as of Jan 2015). It should |
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148 | probably be the max of get_warp(kernel,queue) and |
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149 | device.min_data_type_align_size//4. |
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150 | """ |
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151 | remainder = vector.size % boundary |
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152 | if remainder != 0: |
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153 | size = vector.size + (boundary - remainder) |
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154 | vector = np.hstack((vector, [extra] * (size - vector.size))) |
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155 | return np.ascontiguousarray(vector, dtype=dtype) |
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156 | |
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157 | |
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158 | def compile_model(source, dtype, fast=False): |
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159 | # type: (str, np.dtype, bool) -> cl.Program |
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160 | """ |
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161 | Build a model to run on the gpu. |
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162 | |
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163 | Returns the compiled program and its type. The returned type will |
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164 | be float32 even if the desired type is float64 if any of the |
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165 | devices in the context do not support the cl_khr_fp64 extension. |
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166 | """ |
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167 | source_list = [generate.convert_type(source, dtype)] |
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168 | |
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169 | if dtype == generate.F16: |
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170 | source_list.insert(0, _F16_PRAGMA) |
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171 | elif dtype == generate.F64: |
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172 | source_list.insert(0, _F64_PRAGMA) |
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173 | |
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174 | source_list.insert(0, "#define USE_SINCOS\n") |
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175 | source = "\n".join(source_list) |
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176 | program = SourceModule(source) # no_extern_c=True, include_dirs=[...] |
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177 | return program |
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178 | |
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179 | |
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180 | # for now, this returns one device in the context |
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181 | # TODO: create a context that contains all devices on all platforms |
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182 | class GpuEnvironment(object): |
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183 | """ |
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184 | GPU context, with possibly many devices, and one queue per device. |
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185 | """ |
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186 | def __init__(self, devnum=0): |
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187 | # type: () -> None |
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188 | # Byte boundary for data alignment |
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189 | #self.data_boundary = max(d.min_data_type_align_size |
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190 | # for d in self.context.devices) |
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191 | self.compiled = {} |
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192 | #self.device = cuda.Device(devnum) |
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193 | #self.context = self.device.make_context() |
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194 | |
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195 | def has_type(self, dtype): |
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196 | # type: (np.dtype) -> bool |
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197 | """ |
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198 | Return True if all devices support a given type. |
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199 | """ |
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200 | return True |
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201 | |
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202 | def compile_program(self, name, source, dtype, fast, timestamp): |
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203 | # type: (str, str, np.dtype, bool, float) -> cl.Program |
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204 | """ |
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205 | Compile the program for the device in the given context. |
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206 | """ |
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207 | # Note: PyOpenCL caches based on md5 hash of source, options and device |
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208 | # so we don't really need to cache things for ourselves. I'll do so |
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209 | # anyway just to save some data munging time. |
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210 | tag = generate.tag_source(source) |
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211 | key = "%s-%s-%s%s"%(name, dtype, tag, ("-fast" if fast else "")) |
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212 | # Check timestamp on program |
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213 | program, program_timestamp = self.compiled.get(key, (None, np.inf)) |
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214 | if program_timestamp < timestamp: |
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215 | del self.compiled[key] |
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216 | if key not in self.compiled: |
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217 | logging.info("building %s for CUDA", key) |
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218 | program = compile_model(str(source), dtype, fast) |
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219 | self.compiled[key] = (program, timestamp) |
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220 | return program |
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221 | |
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222 | class GpuModel(KernelModel): |
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223 | """ |
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224 | GPU wrapper for a single model. |
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225 | |
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226 | *source* and *model_info* are the model source and interface as returned |
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227 | from :func:`generate.make_source` and :func:`generate.make_model_info`. |
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228 | |
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229 | *dtype* is the desired model precision. Any numpy dtype for single |
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230 | or double precision floats will do, such as 'f', 'float32' or 'single' |
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231 | for single and 'd', 'float64' or 'double' for double. Double precision |
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232 | is an optional extension which may not be available on all devices. |
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233 | Half precision ('float16','half') may be available on some devices. |
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234 | Fast precision ('fast') is a loose version of single precision, indicating |
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235 | that the compiler is allowed to take shortcuts. |
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236 | """ |
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237 | def __init__(self, source, model_info, dtype=generate.F32, fast=False): |
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238 | # type: (Dict[str,str], ModelInfo, np.dtype, bool) -> None |
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239 | self.info = model_info |
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240 | self.source = source |
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241 | self.dtype = dtype |
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242 | self.fast = fast |
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243 | self.program = None # delay program creation |
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244 | self._kernels = None |
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245 | |
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246 | def __getstate__(self): |
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247 | # type: () -> Tuple[ModelInfo, str, np.dtype, bool] |
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248 | return self.info, self.source, self.dtype, self.fast |
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249 | |
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250 | def __setstate__(self, state): |
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251 | # type: (Tuple[ModelInfo, str, np.dtype, bool]) -> None |
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252 | self.info, self.source, self.dtype, self.fast = state |
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253 | self.program = None |
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254 | |
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255 | def make_kernel(self, q_vectors): |
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256 | # type: (List[np.ndarray]) -> "GpuKernel" |
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257 | if self.program is None: |
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258 | compile_program = environment().compile_program |
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259 | timestamp = generate.ocl_timestamp(self.info) |
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260 | self.program = compile_program( |
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261 | self.info.name, |
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262 | self.source['opencl'], |
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263 | self.dtype, |
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264 | self.fast, |
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265 | timestamp) |
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266 | variants = ['Iq', 'Iqxy', 'Imagnetic'] |
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267 | names = [generate.kernel_name(self.info, k) for k in variants] |
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268 | kernels = [self.program.get_function(k) for k in names] |
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269 | self._kernels = dict((k, v) for k, v in zip(variants, kernels)) |
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270 | is_2d = len(q_vectors) == 2 |
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271 | if is_2d: |
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272 | kernel = [self._kernels['Iqxy'], self._kernels['Imagnetic']] |
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273 | else: |
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274 | kernel = [self._kernels['Iq']]*2 |
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275 | return GpuKernel(kernel, self.dtype, self.info, q_vectors) |
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276 | |
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277 | def release(self): |
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278 | # type: () -> None |
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279 | """ |
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280 | Free the resources associated with the model. |
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281 | """ |
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282 | if self.program is not None: |
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283 | self.program = None |
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284 | |
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285 | def __del__(self): |
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286 | # type: () -> None |
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287 | self.release() |
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288 | |
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289 | # TODO: check that we don't need a destructor for buffers which go out of scope |
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290 | class GpuInput(object): |
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291 | """ |
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292 | Make q data available to the gpu. |
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293 | |
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294 | *q_vectors* is a list of q vectors, which will be *[q]* for 1-D data, |
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295 | and *[qx, qy]* for 2-D data. Internally, the vectors will be reallocated |
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296 | to get the best performance on OpenCL, which may involve shifting and |
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297 | stretching the array to better match the memory architecture. Additional |
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298 | points will be evaluated with *q=1e-3*. |
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299 | |
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300 | *dtype* is the data type for the q vectors. The data type should be |
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301 | set to match that of the kernel, which is an attribute of |
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302 | :class:`GpuProgram`. Note that not all kernels support double |
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303 | precision, so even if the program was created for double precision, |
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304 | the *GpuProgram.dtype* may be single precision. |
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305 | |
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306 | Call :meth:`release` when complete. Even if not called directly, the |
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307 | buffer will be released when the data object is freed. |
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308 | """ |
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309 | def __init__(self, q_vectors, dtype=generate.F32): |
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310 | # type: (List[np.ndarray], np.dtype) -> None |
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311 | # TODO: do we ever need double precision q? |
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312 | self.nq = q_vectors[0].size |
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313 | self.dtype = np.dtype(dtype) |
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314 | self.is_2d = (len(q_vectors) == 2) |
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315 | # TODO: stretch input based on get_warp() |
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316 | # not doing it now since warp depends on kernel, which is not known |
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317 | # at this point, so instead using 32, which is good on the set of |
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318 | # architectures tested so far. |
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319 | if self.is_2d: |
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320 | # Note: 16 rather than 15 because result is 1 longer than input. |
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321 | width = ((self.nq+16)//16)*16 |
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322 | self.q = np.empty((width, 2), dtype=dtype) |
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323 | self.q[:self.nq, 0] = q_vectors[0] |
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324 | self.q[:self.nq, 1] = q_vectors[1] |
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325 | else: |
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326 | # Note: 32 rather than 31 because result is 1 longer than input. |
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327 | width = ((self.nq+32)//32)*32 |
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328 | self.q = np.empty(width, dtype=dtype) |
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329 | self.q[:self.nq] = q_vectors[0] |
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330 | self.global_size = [self.q.shape[0]] |
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331 | #print("creating inputs of size", self.global_size) |
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332 | self.q_b = cuda.to_device(self.q) |
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333 | |
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334 | def release(self): |
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335 | # type: () -> None |
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336 | """ |
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337 | Free the memory. |
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338 | """ |
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339 | if self.q_b is not None: |
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340 | self.q_b.free() |
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341 | self.q_b = None |
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342 | |
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343 | def __del__(self): |
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344 | # type: () -> None |
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345 | self.release() |
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346 | |
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347 | class GpuKernel(Kernel): |
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348 | """ |
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349 | Callable SAS kernel. |
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350 | |
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351 | *kernel* is the GpuKernel object to call |
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352 | |
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353 | *model_info* is the module information |
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354 | |
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355 | *q_vectors* is the q vectors at which the kernel should be evaluated |
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356 | |
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357 | *dtype* is the kernel precision |
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358 | |
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359 | The resulting call method takes the *pars*, a list of values for |
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360 | the fixed parameters to the kernel, and *pd_pars*, a list of (value,weight) |
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361 | vectors for the polydisperse parameters. *cutoff* determines the |
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362 | integration limits: any points with combined weight less than *cutoff* |
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363 | will not be calculated. |
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364 | |
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365 | Call :meth:`release` when done with the kernel instance. |
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366 | """ |
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367 | def __init__(self, kernel, dtype, model_info, q_vectors): |
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368 | # type: (cl.Kernel, np.dtype, ModelInfo, List[np.ndarray]) -> None |
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369 | q_input = GpuInput(q_vectors, dtype) |
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370 | self.kernel = kernel |
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371 | self.info = model_info |
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372 | self.dtype = dtype |
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373 | self.dim = '2d' if q_input.is_2d else '1d' |
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374 | # plus three for the normalization values |
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375 | self.result = np.empty(q_input.nq+1, dtype) |
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376 | |
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377 | # Inputs and outputs for each kernel call |
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378 | # Note: res may be shorter than res_b if global_size != nq |
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379 | self.result_b = cuda.mem_alloc(q_input.global_size[0] * dtype.itemsize) |
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380 | self.q_input = q_input # allocated by GpuInput above |
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381 | |
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382 | self._need_release = [self.result_b, self.q_input] |
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383 | self.real = (np.float32 if dtype == generate.F32 |
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384 | else np.float64 if dtype == generate.F64 |
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385 | else np.float16 if dtype == generate.F16 |
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386 | else np.float32) # will never get here, so use np.float32 |
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387 | |
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388 | def __call__(self, call_details, values, cutoff, magnetic): |
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389 | # type: (CallDetails, np.ndarray, np.ndarray, float, bool) -> np.ndarray |
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390 | # Arrange data transfer to card |
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391 | details_b = cuda.to_device(call_details.buffer) |
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392 | values_b = cuda.to_device(values) |
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393 | |
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394 | kernel = self.kernel[1 if magnetic else 0] |
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395 | args = [ |
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396 | np.uint32(self.q_input.nq), None, None, |
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397 | details_b, values_b, self.q_input.q_b, self.result_b, |
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398 | self.real(cutoff), |
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399 | ] |
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400 | grid = partition(self.q_input.nq) |
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401 | #print("Calling OpenCL") |
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402 | #call_details.show(values) |
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403 | # Call kernel and retrieve results |
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404 | last_nap = time.clock() |
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405 | step = 1000000//self.q_input.nq + 1 |
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406 | #step = 1000000000 |
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407 | for start in range(0, call_details.num_eval, step): |
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408 | stop = min(start + step, call_details.num_eval) |
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409 | #print("queuing",start,stop) |
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410 | args[1:3] = [np.int32(start), np.int32(stop)] |
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411 | kernel(*args, **grid) |
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412 | if stop < call_details.num_eval: |
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413 | sync() |
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414 | # Allow other processes to run |
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415 | current_time = time.clock() |
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416 | if current_time - last_nap > 0.5: |
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417 | time.sleep(0.05) |
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418 | last_nap = current_time |
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419 | sync() |
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420 | details_b.free() |
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421 | values_b.free() |
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422 | cuda.memcpy_dtoh(self.result, self.result_b) |
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423 | #print("result", self.result) |
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424 | |
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425 | pd_norm = self.result[self.q_input.nq] |
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426 | scale = values[0]/(pd_norm if pd_norm != 0.0 else 1.0) |
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427 | background = values[1] |
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428 | #print("scale",scale,values[0],self.result[self.q_input.nq],background) |
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429 | return scale*self.result[:self.q_input.nq] + background |
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430 | # return self.result[:self.q_input.nq] |
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431 | |
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432 | def release(self): |
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433 | # type: () -> None |
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434 | """ |
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435 | Release resources associated with the kernel. |
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436 | """ |
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437 | if self.result_b is not None: |
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438 | self.result_b.free() |
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439 | self.result_b = None |
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440 | |
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441 | def __del__(self): |
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442 | # type: () -> None |
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443 | self.release() |
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444 | |
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445 | |
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446 | def sync(): |
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447 | """ |
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448 | Overview: |
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449 | Waits for operation in the current context to complete. |
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450 | |
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451 | Note: Maybe context.synchronize() is sufficient. |
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452 | """ |
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453 | #return # The following works in C++; don't know what pycuda is doing |
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454 | # Create an event with which to synchronize |
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455 | done = cuda.Event() |
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456 | |
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457 | # Schedule an event trigger on the GPU. |
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458 | done.record() |
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459 | |
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460 | #line added to not hog resources |
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461 | while not done.query(): time.sleep(0.01) |
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462 | |
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463 | # Block until the GPU executes the kernel. |
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464 | done.synchronize() |
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465 | # Clean up the event; I don't think they can be reused. |
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466 | del done |
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467 | |
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468 | |
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469 | def partition(n): |
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470 | ''' |
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471 | Overview: |
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472 | Auto grids the thread blocks to achieve some level of calculation |
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473 | efficiency. |
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474 | ''' |
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475 | max_gx,max_gy = 65535,65535 |
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476 | blocksize = 32 |
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477 | #max_gx,max_gy = 5,65536 |
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478 | #blocksize = 3 |
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479 | block = (blocksize,1,1) |
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480 | num_blocks = int((n+blocksize-1)/blocksize) |
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481 | if num_blocks < max_gx: |
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482 | grid = (num_blocks,1) |
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483 | else: |
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484 | gx = max_gx |
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485 | gy = (num_blocks + max_gx - 1) / max_gx |
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486 | if gy >= max_gy: raise ValueError("vector is too large") |
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487 | grid = (gx,gy) |
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488 | #print "block",block,"grid",grid |
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489 | #print "waste",block[0]*block[1]*block[2]*grid[0]*grid[1] - n |
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490 | return dict(block=block,grid=grid) |
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491 | |
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