Benchmarking forcing functions

benchmark/benchmark_forcing_functions.jl

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+using TimerOutputs, Printf
+
+using Oceananigans
+
+const timer = TimerOutput()
+
+Ni = 2   # Number of iterations before benchmarking starts.
+Nt = 10  # Number of iterations to use for benchmarking time stepping.
+
+# Run benchmark across these parameters.
+            Ns = [(128, 128, 128)]
+   float_types = [Float64]  # Float types to benchmark.
+         archs = [CPU()]    # Architectures to benchmark on.
+@hascuda archs = [GPU()]    # Benchmark GPU on systems with CUDA-enabled GPUs.
+
+arch_name(::String) = ""
+arch_name(::CPU) = "CPU"
+arch_name(::GPU) = "GPU"
+
+function benchmark_name(N, id, arch, FT; npad=2)
+    Nx, Ny, Nz = N
+
+    bn = ""
+    bn *= lpad(Nx, npad, " ") * "×" * lpad(Ny, npad, " ") * "×" * lpad(Nz, npad, " ")
+    bn *= " $id"
+
+    arch = arch_name(arch)
+    bn *= " ($arch, $FT)"
+
+    return bn
+end
+
+benchmark_name(N, id) = benchmark_name(N, id, "", "", "")
+
+@inline function Fu(grid, U, Φ, i, j, k)
+    if k == 1
+        return @inbounds -2*0.1/grid.Δz^2 * (U.u[i, j, 1] - 0)
+    elseif k == grid.Nz
+        return @inbounds -2*0.1/grid.Δz^2 * (U.u[i, j, grid.Nz] - 0)
+    else
+        return 0
+    end
+end
+
+@inline FT(grid, U, Φ, i, j, k) = @inbounds ifelse(k == 1, -1e-4 * (Φ.T[i, j, 1] - 0), 0)
+forcing = Forcing(Fu=Fu, FT=FT)
+
+for arch in archs, float_type in float_types, N in Ns
+    Nx, Ny, Nz = N
+    Lx, Ly, Lz = 1, 1, 1
+
+    forced_model = Model(N=(Nx, Ny, Nz), L=(Lx, Ly, Lz), arch=arch, float_type=float_type, forcing=forcing)
+    time_step!(forced_model, Ni, 1)  # First 1-2 iterations usually slower.
+
+    bn =  benchmark_name(N, "with forcing", arch, float_type)
+    @printf("Running benchmark: %s...\n", bn)
+    for i in 1:Nt
+        @timeit timer bn time_step!(forced_model, 1, 1)
+    end
+
+    unforced_model = Model(N=(Nx, Ny, Nz), L=(Lx, Ly, Lz), arch=arch, float_type=float_type)
+    time_step!(unforced_model, Ni, 1)  # First 1-2 iterations usually slower.
+
+    bn =  benchmark_name(N, "  no forcing", arch, float_type)
+    @printf("Running benchmark: %s...\n", bn)
+    for i in 1:Nt
+        @timeit timer bn time_step!(unforced_model, 1, 1)
+    end
+end
+
+print_timer(timer, title="Forcing function benchmarks")
+println("")
+