Modularized the examples/pybind11/onemkl_gemv/sycl_timing_solver.py (#838)

Author: oleksandr-pavlyk

examples/pybind11/onemkl_gemv/sycl_timing_solver.py

@@ -63,41 +63,66 @@
 
 timer = dpctl.SyclTimer(time_scale=1e3)
 
-iters = []
-for i in range(6):
-    with timer(api_dev.sycl_queue):
-        x, conv_in = solve.cg_solve(A, b)
-
-    print(i, "(host_dt, device_dt)=", timer.dt)
-    iters.append(conv_in)
-    assert x.usm_type == A.usm_type
-    assert x.usm_type == b.usm_type
-    assert x.sycl_queue == A.sycl_queue
-    assert x.sycl_queue == b.sycl_queue
-
-print("Converged in: ", iters)
-
-hev, ev = sycl_gemm.gemv(q, A, x, r)
-hev2, ev2 = sycl_gemm.sub(q, r, b, delta, [ev])
-rs = sycl_gemm.norm_squared_blocking(q, delta)
-dpctl.SyclEvent.wait_for([hev, hev2])
-print(f"Python solution residual norm squared: {rs}")
+
+def time_python_solver(num_iters=6):
+    """
+    Time solver implemented in Python with use of asynchronous
+    SYCL kernel submission.
+    """
+    global x
+    iters = []
+    for i in range(num_iters):
+        with timer(api_dev.sycl_queue):
+            x, conv_in = solve.cg_solve(A, b)
+
+        print(i, "(host_dt, device_dt)=", timer.dt)
+        iters.append(conv_in)
+        assert x.usm_type == A.usm_type
+        assert x.usm_type == b.usm_type
+        assert x.sycl_queue == A.sycl_queue
+        assert x.sycl_queue == b.sycl_queue
+
+    return iters
+
+
+def time_cpp_solver(num_iters=6):
+    """
+    Time solver implemented in C++ but callable from Python.
+    C++ implementation uses the same algorithm and submits same
+    kernels asynchronously, but bypasses Python binding overhead
+    incurred when algorithm is driver from Python.
+    """
+    global x_cpp
+    x_cpp = dpt.empty_like(b)
+    iters = []
+    for i in range(num_iters):
+        with timer(api_dev.sycl_queue):
+            conv_in = sycl_gemm.cpp_cg_solve(q, A, b, x_cpp)
+
+        print(i, "(host_dt, device_dt)=", timer.dt)
+        iters.append(conv_in)
+
+    return iters
+
+
+def compute_residual(x):
+    """
+    Computes quality of the solution, `norm_squared(A@x - b)`.
+    """
+    assert isinstance(x, dpt.usm_ndarray)
+    q = A.sycl_queue
+    hev, ev = sycl_gemm.gemv(q, A, x, r)
+    hev2, ev2 = sycl_gemm.sub(q, r, b, delta, [ev])
+    rs = sycl_gemm.norm_squared_blocking(q, delta)
+    dpctl.SyclEvent.wait_for([hev, hev2])
+    return rs
+
+
+print("Converged in: ", time_python_solver())
+print(f"Python solution residual norm squared: {compute_residual(x)}")
 
 assert q == api_dev.sycl_queue
 print("")
 
-x_cpp = dpt.empty_like(b)
-iters = []
-for i in range(6):
-    with timer(api_dev.sycl_queue):
-        conv_in = sycl_gemm.cpp_cg_solve(q, A, b, x_cpp)
-
-    print(i, "(host_dt, device_dt)=", timer.dt)
-    iters.append(conv_in)
-
-print("Converged in: ", iters)
-hev, ev = sycl_gemm.gemv(q, A, x_cpp, r)
-hev2, ev2 = sycl_gemm.sub(q, r, b, delta, [ev])
-rs = sycl_gemm.norm_squared_blocking(q, delta)
-dpctl.SyclEvent.wait_for([hev, hev2])
-print(f"cpp_cg_solve solution residual norm squared: {rs}")
+print("Converged in: ", time_cpp_solver())
+print(f"cpp_cg_solve solution residual norm squared: {compute_residual(x_cpp)}")