sql/tests: disable profiling during sysbench setup

This commit disables memory, mutex, and block profiling during sysbench
setup. All three of these profile types record events from process startup
onward if we don't manully disable them.

Epic: None
Release note: None

pkg/sql/tests/sysbench_test.go

@@ -9,6 +9,7 @@ import (
 	"context"
 	"fmt"
 	"math/rand"
+	"runtime"
 	"slices"
 	"testing"
 
@@ -638,23 +639,44 @@ func BenchmarkSysbench(b *testing.B) {
 						}
 					}()
 
+					// Set up the cluster and dataset.
+					disableProfiling()
 					ctx := context.Background()
 					sys, cleanup := driver.constructorFn(ctx, b)
 					defer cleanup()
-
 					rng := rand.New(rand.NewSource(0))
 					sys.prep(rng)
 
+					// Start profiling and timer, then run the workload.
+					enableProfiling()
 					b.ResetTimer()
+					b.ReportAllocs()
 					for i := 0; i < b.N; i++ {
 						workload.opFn(sys, rng)
 					}
+
+					// Stop timer and profiling to exclude (deferred) cluster teardown.
+					b.StopTimer()
+					disableProfiling()
 				})
 			}
 		})
 	}
 }
 
+func disableProfiling() {
+	runtime.MemProfileRate = 0
+	runtime.SetMutexProfileFraction(0)
+	runtime.SetBlockProfileRate(0)
+}
+
+func enableProfiling() {
+	runtime.GC()
+	runtime.MemProfileRate = 1
+	runtime.SetMutexProfileFraction(1)
+	runtime.SetBlockProfileRate(1)
+}
+
 func try0(err error) {
 	if err != nil {
 		panic(errors.WrapWithDepth(1, err, "try failed"))