Performance test time reduction

1) Use 32MiB per core for bandwidth
2) Use 16MiB for latency

cmd/cxl-util/main.go

@@ -16,7 +16,7 @@ import (
 	"k8s.io/klog/v2"
 )
 
-var Version = "1.0.0"
+var Version = "1.3.2"
 
 // This variable is filled in during the linker step - -ldflags "-X main.buildTime=`date -u '+%Y-%m-%dT%H:%M:%S'`"
 var buildTime = ""
@@ -168,6 +168,11 @@ func main() {
 
 				if dev.Cdat != nil {
 					dev.Cdat.PrintAllCDAT()
+
+					devPerf := dev.Cdat.Get_CDAT_DSLBIS_performance()
+					fmt.Print("\nCDAT DSLBIS reported performance:")
+					fmt.Println("\nCDAT DSLBIS reported performance:", devPerf)
+
 				} else {
 					fmt.Printf("\n\nCDAT is not available on dev: %s\n", settings.PCIE)
 				}
@@ -212,11 +217,6 @@ func main() {
 
 			}
 
-			if dev.Cdat != nil {
-				devPerf := dev.Cdat.Get_CDAT_DSLBIS_performance()
-				fmt.Print("\nCDAT DSLBIS reported performance:")
-				fmt.Println("\nCDAT DSLBIS reported performance:", devPerf)
-			}
 			devBW, err := dev.MeasureBandwidth()
 			if err == nil {
 				fmt.Printf("\nMeasured Bandwidth: %.2f GiB/s\n", devBW)

go.mod

@@ -1,6 +1,6 @@
 module github.com/Seagate/cxl-lib
 
-go 1.20
+go 1.22.1
 
 require k8s.io/klog/v2 v2.100.1
 

pkg/cxl/cxl-util.go

@@ -524,7 +524,7 @@ func (c *CxlDev) MeasureLatency() (uint64, error) {
 	var diff time.Duration
 
 	startAddr := c.GetMemoryBaseAddr()
-	testSize := 128 << 20 // 128MiB should be enough for latency measurement while not taking too long
+	testSize := 16 << 20 // Limit to 16MiB test size
 
 	mem_file, err := os.OpenFile("/dev/mem", os.O_RDWR|os.O_SYNC, 0)
 	if err != nil {
@@ -572,7 +572,7 @@ func (c *CxlDev) MeasureLatency() (uint64, error) {
 
 	lat := uint64(diff.Nanoseconds() / int64(testSize>>3))
 
-	klog.V(DBG_LVL_BASIC).Infof("cxlDev.MeasureBandwidth: totalSize %d MiB, time %d ns", testSize>>20, diff.Nanoseconds())
+	klog.V(DBG_LVL_BASIC).Infof("cxlDev.MeasureLatency: totalSize %d MiB, time %d ns", testSize>>20, diff.Nanoseconds())
 	klog.V(DBG_LVL_BASIC).Infof("Average memory latency: %d ns\n", lat)
 
 	return lat, nil
@@ -603,8 +603,11 @@ func (c *CxlDev) MeasureBandwidth() (float64, error) {
 	var start, end time.Time
 	var diff time.Duration
 
-	startAddr := c.GetMemoryBaseAddr()
-	totalSize := int(c.GetMemorySize())
+	numCPU := runtime.NumCPU()
+
+	// Measure 1GiB from the middle of the memory
+	startAddr := c.GetMemoryBaseAddr() + c.GetMemorySize()/2
+	totalSize := min(int(c.GetMemorySize()), numCPU<<25) // 32MiB per core
 
 	mem_file, err := os.OpenFile("/dev/mem", os.O_RDWR|os.O_SYNC, 0)
 	if err != nil {
@@ -618,7 +621,6 @@ func (c *CxlDev) MeasureBandwidth() (float64, error) {
 	}
 
 	mRange := (*memRange)(unsafe.Pointer(&mmap))
-	numCPU := runtime.NumCPU()
 	ch := make(chan int, numCPU) // Buffering optional but sensible.
 
 	// fill the test area