add benchmark scritp for dot (apache#59)

* add benchmark scritp for dot

add gpu option for bench

add get_data funciton for benchmark

print t_sparse, too;

add comment

change nnz to dnesity

add backward

* add comment

benchmark/python/sparse_op.py

@@ -0,0 +1,143 @@
+# pylint: skip-file
+import mxnet as mx
+from mxnet.test_utils import *
+import numpy as np
+import scipy.sparse as sp
+import os, gzip
+import pickle as pickle
+import time
+import sys
+
+def get_avazu(data_dir):
+    if not os.path.isdir(data_dir):
+        os.system("mkdir " + data_dir)
+    os.chdir(data_dir)
+    if (not os.path.exists('avazu-app.t')):
+        import urllib, zipfile
+        zippath = os.path.join(data_dir, "avazu-app.t.bz2")
+        url = "https://www.csie.ntu.edu.tw/~cjlin/libsvmtools/datasets/binary/avazu-app.t.bz2"
+        urllib.urlretrieve(url, zippath)
+        # decompress
+        os.system("bzip2 -d avazu-app.t.bz2")
+    os.chdir("..")
+
+def test_dot_real():
+    def get_iter(path, data_shape, batch_size):
+        data_train = mx.io.LibSVMIter(data_libsvm=path,
+                                      data_shape=data_shape,
+                                      batch_size=batch_size)
+        data_iter = iter(data_train)
+        return data_iter
+    data_dir = os.path.join(os.getcwd(), 'data')
+    get_avazu(data_dir)
+    path = os.path.join(data_dir, 'avazu-app.t')
+    # TODO(haibin) get file size automatically
+    size = 336490781 >> 20
+
+    # model
+    batch_size = 512
+    feature_dim = 1000000
+    data_shape = (feature_dim, )
+    train_iter = get_iter(path, data_shape, batch_size)
+
+    k = 500
+    weight = mx.nd.random_uniform(low=0, high=1, shape=(feature_dim, k)) 
+    weight.wait_to_read()
+
+    # start workload
+    start = time.time()
+    results = []
+    num_batch = 0
+    for batch in train_iter:
+        data = train_iter.getdata()
+        results.append(mx.nd.dot(data, weight))
+        num_batch += 1
+    for result in results:
+        result.wait_to_read()
+
+    end = time.time()
+    cost = end - start
+    print(size / cost, cost, num_batch, num_batch / cost)
+
+def test_dot_synthetic():
+    """benchmark mx.nd.dot(sparse_ndarray, dense_ndarray) with given density.
+    `t_sparse` is the time cost of dot(csr, dns), while `t_dense` is the time cost
+    of dot(dns, dns), with the same matrix except that it is in default storage type.
+    """
+    def measure_cost(repeat, f, *args, **kwargs):
+       # start bench
+       start = time.time()
+       results = []
+       for i in range(repeat):
+           results.append(f(*args, **kwargs))
+       for result in results:
+           result.wait_to_read()
+       end = time.time()
+       diff = end - start
+       return diff / repeat
+
+    def bench_dot_forward(m, k, n, density, ctx, repeat):
+        set_default_context(ctx)
+        dns = mx.nd.random_uniform(shape=(k, n)).copyto(ctx)
+        data_shape = (m, k)
+        csr_data = rand_ndarray(data_shape, 'csr', density)
+        dns_data = csr_data.to_dense()
+
+        data = [dns_data, csr_data]
+        costs = []
+        for d in data:
+            dns.wait_to_read()
+            d.wait_to_read()
+            cost = measure_cost(repeat, mx.nd.dot, d, dns)
+            costs.append(cost / repeat)
+        ratio = costs[1] / costs[0]
+        fmt = "%0.1f\t\t%s\t%d\t%d\t%d\t%0.6f\t%0.5f\t%0.2f"
+        print(fmt % (density * 100, str(ctx), n, m, k, costs[1], costs[0], ratio))
+
+    def bench_dot_backward(m, k, n, density, ctx, repeat):
+        set_default_context(ctx)
+        dns = mx.nd.random_uniform(shape=(m, n)).copyto(ctx)
+        data_shape = (m, k)
+        csr_data = rand_ndarray(data_shape, 'csr', density)
+        dns_data = csr_data.to_dense()
+
+        data = [dns_data, csr_data]
+        costs = []
+        for d in data:
+            dns.wait_to_read()
+            d.wait_to_read()
+            cost = measure_cost(repeat, mx.nd.dot, d, dns, transpose_a=True)
+            costs.append(cost)
+        ratio = costs[1] / costs[0]
+        fmt = "%0.1f\t\t%s\t%d\t%d\t%d\t%0.6f\t%0.5f\t%0.2f"
+        print(fmt % (density * 100, str(ctx), n, m, k, costs[1], costs[0], ratio))
+
+
+    print("A = sparse NDArray of shape(m, k)")
+    print("B = dense NDArray of shape(k, n)")
+    print("dot_forward\tdot(csr, dns)")
+    print('density(%)\tcontext\tn\tm\tk\tt_sparse\tt_dense\tt_sparse/t_dense')
+
+    # TODO(haibin) make these runtime options
+    m = 512
+    k = [50000, 100000]
+    n = [50, 100]
+    density = [0.05, 0.02, 0.01, 0.005, 0.001]
+    num_repeat = 10
+    # contexts = [mx.cpu(), mx.gpu(0)]
+    contexts = [mx.cpu()]
+    for i in range(2):
+        for ctx in contexts:
+            for den in density:
+                bench_dot_forward(m, k[i], n[i], den, ctx, num_repeat)
+
+    print("dot_backward\tdot(csr.T, dns)")
+    print('density(%)\tcontext\tn\tm\tk\tt_sparse\tt_dense\tt_sparse/t_dense')
+    for i in range(2):
+        for ctx in contexts:
+            for den in density:
+                bench_dot_backward(m, k[i], n[i], den, ctx, num_repeat)
+
+if __name__ == "__main__":
+    test_dot_real()
+    test_dot_synthetic()