Simplify profiling and benchmarks.

- Tweak the benchmarks to work with b.N where appropriate. In many cases,
  b.N was simply being ignored. This creates an implicit dependency in the
  user passing a reasonable benchtime (less than or equal to the actual
  runtime of the test, or using the X syntax) otherwise the test runs
  forever.
- In cases where the above is impossible, explicitly set benchtime from
  the test wrapper, to prevent the above behavior (tensorflow).
- Drop the *Reverse variants, which are simply hey benchmarks. We should
  just add a hey benchmark. The platforms benchmarks already include a
  native platform, and thus these benchmarks are incredibly confusing.
  (In other words, BenchmarkNginxReverse has nothing to do with an nginx
  benchmark for runsc.)
- Remove the redunant Harness object, which contains no state, in order
  to slightly simplify the code.
- Make Block and Heap profiling actually work, but setting appropriate
  runtime parameters (and plumbing them through the config).
- Split the profiling into two phases: start and stop, since some will
  need to be started early, and others will need to happen at the end.

PiperOrigin-RevId: 349495377

2 files changed, 46 insertions, 39 deletions

diff --git a/test/benchmarks/fs/bazel_test.go b/test/benchmarks/fs/bazel_test.go
index 3fb4da9d1..8baeff0db 100644
--- a/test/benchmarks/fs/bazel_test.go
+++ b/test/benchmarks/fs/bazel_test.go
@@ -25,8 +25,6 @@ import (
 	"gvisor.dev/gvisor/test/benchmarks/tools"
 )
 
-var h harness.Harness
-
 // Note: CleanCache versions of this test require running with root permissions.
 func BenchmarkBuildABSL(b *testing.B) {
 	runBuildBenchmark(b, "benchmarks/absl", "/abseil-cpp", "absl/base/...")
@@ -41,7 +39,7 @@ func BenchmarkBuildRunsc(b *testing.B) {
 func runBuildBenchmark(b *testing.B, image, workdir, target string) {
 	b.Helper()
 	// Get a machine from the Harness on which to run.
-	machine, err := h.GetMachine()
+	machine, err := harness.GetMachine()
 	if err != nil {
 		b.Fatalf("failed to get machine: %v", err)
 	}
@@ -102,21 +100,20 @@ func runBuildBenchmark(b *testing.B, image, workdir, target string) {
 				prefix = "/tmp"
 			}
 
-			// Restart profiles after the copy.
-			container.RestartProfiles()
 			b.ResetTimer()
+			b.StopTimer()
+
 			// Drop Caches and bazel clean should happen inside the loop as we may use
 			// time options with b.N. (e.g. Run for an hour.)
 			for i := 0; i < b.N; i++ {
-				b.StopTimer()
 				// Drop Caches for clear cache runs.
 				if bm.clearCache {
 					if err := harness.DropCaches(machine); err != nil {
 						b.Skipf("failed to drop caches: %v. You probably need root.", err)
 					}
 				}
-				b.StartTimer()
 
+				b.StartTimer()
 				got, err := container.Exec(ctx, dockerutil.ExecOpts{
 					WorkDir: prefix + workdir,
 				}, "bazel", "build", "-c", "opt", target)
@@ -138,7 +135,6 @@ func runBuildBenchmark(b *testing.B, image, workdir, target string) {
 						b.Fatalf("build failed with: %v", err)
 					}
 				}
-				b.StartTimer()
 			}
 		})
 	}
@@ -146,6 +142,7 @@ func runBuildBenchmark(b *testing.B, image, workdir, target string) {
 
 // TestMain is the main method for package fs.
 func TestMain(m *testing.M) {
-	h.Init()
+	harness.Init()
+	harness.SetFixedBenchmarks()
 	os.Exit(m.Run())
 }
diff --git a/test/benchmarks/fs/fio_test.go b/test/benchmarks/fs/fio_test.go
index 96340373c..0c772b768 100644
--- a/test/benchmarks/fs/fio_test.go
+++ b/test/benchmarks/fs/fio_test.go
@@ -27,42 +27,50 @@ import (
 	"gvisor.dev/gvisor/test/benchmarks/tools"
 )
 
-var h harness.Harness
-
 // BenchmarkFio runs fio on the runtime under test. There are 4 basic test
 // cases each run on a tmpfs mount and a bind mount. Fio requires root so that
 // caches can be dropped.
 func BenchmarkFio(b *testing.B) {
 	testCases := []tools.Fio{
 		tools.Fio{
-			Test:      "write",
-			Size:      "5G",
-			Blocksize: "1M",
-			Iodepth:   4,
+			Test:      "write4K",
+			Size:      b.N,
+			BlockSize: 4,
+			IODepth:   4,
+		},
+		tools.Fio{
+			Test:      "write1M",
+			Size:      b.N,
+			BlockSize: 1024,
+			IODepth:   4,
+		},
+		tools.Fio{
+			Test:      "read4K",
+			Size:      b.N,
+			BlockSize: 4,
+			IODepth:   4,
 		},
 		tools.Fio{
-			Test:      "read",
-			Size:      "5G",
-			Blocksize: "1M",
-			Iodepth:   4,
+			Test:      "read1M",
+			Size:      b.N,
+			BlockSize: 1024,
+			IODepth:   4,
 		},
 		tools.Fio{
-			Test:      "randwrite",
-			Size:      "5G",
-			Blocksize: "4K",
-			Iodepth:   4,
-			Time:      30,
+			Test:      "randwrite4K",
+			Size:      b.N,
+			BlockSize: 4,
+			IODepth:   4,
 		},
 		tools.Fio{
-			Test:      "randread",
-			Size:      "5G",
-			Blocksize: "4K",
-			Iodepth:   4,
-			Time:      30,
+			Test:      "randread4K",
+			Size:      b.N,
+			BlockSize: 4,
+			IODepth:   4,
 		},
 	}
 
-	machine, err := h.GetMachine()
+	machine, err := harness.GetMachine()
 	if err != nil {
 		b.Fatalf("failed to get machine with: %v", err)
 	}
@@ -116,7 +124,7 @@ func BenchmarkFio(b *testing.B) {
 
 				// For reads, we need a file to read so make one inside the container.
 				if strings.Contains(tc.Test, "read") {
-					fallocateCmd := fmt.Sprintf("fallocate -l %s %s", tc.Size, outfile)
+					fallocateCmd := fmt.Sprintf("fallocate -l %dK %s", tc.Size, outfile)
 					if out, err := container.Exec(ctx, dockerutil.ExecOpts{},
 						strings.Split(fallocateCmd, " ")...); err != nil {
 						b.Fatalf("failed to create readable file on mount: %v, %s", err, out)
@@ -128,22 +136,24 @@ func BenchmarkFio(b *testing.B) {
 					b.Skipf("failed to drop caches with %v. You probably need root.", err)
 				}
 				cmd := tc.MakeCmd(outfile)
-				container.RestartProfiles()
+
 				b.ResetTimer()
+				b.StopTimer()
+
 				for i := 0; i < b.N; i++ {
+					if err := harness.DropCaches(machine); err != nil {
+						b.Fatalf("failed to drop caches: %v", err)
+					}
+
 					// Run fio.
+					b.StartTimer()
 					data, err := container.Exec(ctx, dockerutil.ExecOpts{}, cmd...)
 					if err != nil {
 						b.Fatalf("failed to run cmd %v: %v", cmd, err)
 					}
 					b.StopTimer()
+					b.SetBytes(1024 * 1024) // Bytes for go reporting (Size is in megabytes).
 					tc.Report(b, data)
-					// If b.N is used (i.e. we run for an hour), we should drop caches
-					// after each run.
-					if err := harness.DropCaches(machine); err != nil {
-						b.Fatalf("failed to drop caches: %v", err)
-					}
-					b.StartTimer()
 				}
 			})
 		}
@@ -185,6 +195,6 @@ func makeMount(machine harness.Machine, mountType mount.Type, target string) (mo
 
 // TestMain is the main method for package fs.
 func TestMain(m *testing.M) {
-	h.Init()
+	harness.Init()
 	os.Exit(m.Run())
 }