Add parallel tuning on multiple remote GPUs using Ray

examples/cuda/sepconv_parallel.py

@@ -0,0 +1,88 @@
+#!/usr/bin/env python
+import numpy
+from kernel_tuner import tune_kernel
+from collections import OrderedDict
+
+
+def tune():
+    with open("convolution.cu", "r") as f:
+        kernel_string = f.read()
+
+    # setup tunable parameters
+    tune_params = OrderedDict()
+    tune_params["filter_height"] = [i for i in range(3, 19, 2)]
+    tune_params["filter_width"] = [i for i in range(3, 19, 2)]
+    tune_params["block_size_x"] = [16 * i for i in range(1, 65)]
+    tune_params["block_size_y"] = [2**i for i in range(6)]
+    tune_params["tile_size_x"] = [i for i in range(1, 11)]
+    tune_params["tile_size_y"] = [i for i in range(1, 11)]
+
+    tune_params["use_padding"] = [0, 1]  # toggle the insertion of padding in shared memory
+    tune_params["read_only"] = [0, 1]  # toggle using the read-only cache
+
+    # limit the search to only use padding when its effective, and at least 32 threads in a block
+    restrict = ["use_padding==0 or (block_size_x % 32 != 0)", "block_size_x*block_size_y >= 32"]
+
+    # setup input and output dimensions
+    problem_size = (4096, 4096)
+    size = numpy.prod(problem_size)
+    largest_fh = max(tune_params["filter_height"])
+    largest_fw = max(tune_params["filter_width"])
+    input_size = (problem_size[0] + largest_fw - 1) * (problem_size[1] + largest_fh - 1)
+
+    # create input data
+    output_image = numpy.zeros(size).astype(numpy.float32)
+    input_image = numpy.random.randn(input_size).astype(numpy.float32)
+    filter_weights = numpy.random.randn(largest_fh * largest_fw).astype(numpy.float32)
+
+    # setup kernel arguments
+    cmem_args = {"d_filter": filter_weights}
+    args = [output_image, input_image, filter_weights]
+
+    # tell the Kernel Tuner how to compute grid dimensions
+    grid_div_x = ["block_size_x", "tile_size_x"]
+    grid_div_y = ["block_size_y", "tile_size_y"]
+
+    # start tuning separable convolution (row)
+    tune_params["filter_height"] = [1]
+    tune_params["tile_size_y"] = [1]
+    results_row = tune_kernel(
+        "convolution_kernel",
+        kernel_string,
+        problem_size,
+        args,
+        tune_params,
+        grid_div_y=grid_div_y,
+        grid_div_x=grid_div_x,
+        cmem_args=cmem_args,
+        verbose=False,
+        restrictions=restrict,
+        parallel_runner=1024,
+        cache="convolution_kernel_row",
+    )
+
+    # start tuning separable convolution (col)
+    tune_params["filter_height"] = tune_params["filter_width"][:]
+    tune_params["file_size_y"] = tune_params["tile_size_x"][:]
+    tune_params["filter_width"] = [1]
+    tune_params["tile_size_x"] = [1]
+    results_col = tune_kernel(
+        "convolution_kernel",
+        kernel_string,
+        problem_size,
+        args,
+        tune_params,
+        grid_div_y=grid_div_y,
+        grid_div_x=grid_div_x,
+        cmem_args=cmem_args,
+        verbose=False,
+        restrictions=restrict,
+        parallel_runner=1024,
+        cache="convolution_kernel_col",
+    )
+
+    return results_row, results_col
+
+
+if __name__ == "__main__":
+    results_row, results_col = tune()

examples/cuda/vector_add_parallel.py

@@ -0,0 +1,35 @@
+#!/usr/bin/env python
+
+import numpy
+from kernel_tuner import tune_kernel
+
+
+def tune():
+    kernel_string = """
+    __global__ void vector_add(float *c, float *a, float *b, int n) {
+        int i = (blockIdx.x * block_size_x) + threadIdx.x;
+        if ( i < n ) {
+            c[i] = a[i] + b[i];
+        }
+    }
+    """
+
+    size = 10000000
+
+    a = numpy.random.randn(size).astype(numpy.float32)
+    b = numpy.random.randn(size).astype(numpy.float32)
+    c = numpy.zeros_like(b)
+    n = numpy.int32(size)
+
+    args = [c, a, b, n]
+
+    tune_params = dict()
+    tune_params["block_size_x"] = [32 * i for i in range(1, 33)]
+
+    results, env = tune_kernel("vector_add", kernel_string, size, args, tune_params, parallel_workers=True)
+    print(env)
+    return results
+
+
+if __name__ == "__main__":
+    tune()

kernel_tuner/interface.py

@@ -39,8 +39,6 @@
 import kernel_tuner.util as util
 from kernel_tuner.file_utils import get_input_file, get_t4_metadata, get_t4_results, import_class_from_file
 from kernel_tuner.integration import get_objective_defaults
-from kernel_tuner.runners.sequential import SequentialRunner
-from kernel_tuner.runners.simulation import SimulationRunner
 from kernel_tuner.searchspace import Searchspace
 
 try:
@@ -473,6 +471,7 @@ def __deepcopy__(self, _):
         ),
         ("metrics", ("specifies user-defined metrics, please see :ref:`metrics`.", "dict")),
         ("simulation_mode", ("Simulate an auto-tuning search from an existing cachefile", "bool")),
+        ("parallel_workers", ("Set to `True` or an integer to enable parallel tuning. If set to an integer, this will be the number of parallel workers.", "int|bool")),
         ("observers", ("""A list of Observers to use during tuning, please see :ref:`observers`.""", "list")),
     ]
 )
@@ -584,6 +583,7 @@ def tune_kernel(
     cache=None,
     metrics=None,
     simulation_mode=False,
+    parallel_workers=None,
     observers=None,
     objective=None,
     objective_higher_is_better=None,
@@ -651,9 +651,22 @@ def tune_kernel(
         strategy = brute_force
 
     # select the runner for this job based on input
-    selected_runner = SimulationRunner if simulation_mode else SequentialRunner
+    # TODO: we could use the "match case" syntax when removing support for 3.9
     tuning_options.simulated_time = 0
-    runner = selected_runner(kernelsource, kernel_options, device_options, iterations, observers)
+
+    if parallel_workers and simulation_mode:
+        raise ValueError("Enabling `parallel_workers` and `simulation_mode` together is not supported")
+    elif simulation_mode:
+        from kernel_tuner.runners.simulation import SimulationRunner
+        runner = SimulationRunner(kernelsource, kernel_options, device_options, iterations, observers)
+    elif parallel_workers:
+        from kernel_tuner.runners.parallel import ParallelRunner
+        num_workers = None if parallel_workers is True else parallel_workers
+        runner = ParallelRunner(kernelsource, kernel_options, device_options, tuning_options, iterations, observers, num_workers=num_workers)
+    else:
+        from kernel_tuner.runners.sequential import SequentialRunner
+        runner = SequentialRunner(kernelsource, kernel_options, device_options, iterations, observers)
+
 
     # the user-specified function may or may not have an optional atol argument;
     # we normalize it so that it always accepts atol.
@@ -669,16 +682,20 @@ def preprocess_cache(filepath):
     # process cache
     if cache:
         cache = preprocess_cache(cache)
-        util.process_cache(cache, kernel_options, tuning_options, runner)
+        tuning_options.cachefile = cache
+        tuning_options.cache = util.process_cache(cache, kernel_options, tuning_options, runner)
     else:
-        tuning_options.cache = {}
         tuning_options.cachefile = None
+        tuning_options.cache = {}
 
     # create search space
     tuning_options.restrictions_unmodified = deepcopy(restrictions)
-    searchspace = Searchspace(tune_params, restrictions, runner.dev.max_threads, **searchspace_construction_options)
+    device_info = runner.get_device_info()
+    searchspace = Searchspace(tune_params, restrictions, device_info.max_threads, **searchspace_construction_options)
+
     restrictions = searchspace._modified_restrictions
     tuning_options.restrictions = restrictions
+
     if verbose:
         print(f"Searchspace has {searchspace.size} configurations after restrictions.")
 
@@ -696,6 +713,9 @@ def preprocess_cache(filepath):
     results = strategy.tune(searchspace, runner, tuning_options)
     env = runner.get_environment(tuning_options)
 
+    # Shut down the runner
+    runner.shutdown()
+
     # finished iterating over search space
     if results:  # checks if results is not empty
         best_config = util.get_best_config(results, objective, objective_higher_is_better)