Automatically set the number of CPUs.

example/main.go

@@ -6,8 +6,8 @@ import (
 	"fmt"
 	"os"
 	"flag"
+	"runtime"
 )
-
 func main() {
 	// Scans the arg list and sets up flags
 	debug := flag.Bool("debug", false, "print debugging messages.")
@@ -27,7 +27,11 @@ func main() {
 
 	mountPoint := flag.Arg(1)
 	state.Mount(mountPoint)
-
-	fmt.Printf("Mounted %s on %s (threaded=%v, debug=%v)\n", orig, mountPoint, *threaded, *debug)
+	cpus := fuse.CountCpus()
+	if cpus > 1 {
+		runtime.GOMAXPROCS(cpus)
+	}
+	
+	fmt.Printf("Mounted %s on %s (threaded=%v, debug=%v, cpus=%v)\n", orig, mountPoint, *threaded, *debug, cpus)
 	state.Loop(*threaded)
 }

fuse/misc.go

@@ -11,6 +11,7 @@ import (
 	"fmt"
 	"path"
 	"math"
+	"regexp"
 	"syscall"
 	"unsafe"
 )
@@ -268,3 +269,17 @@ func Writev(fd int, packet [][]byte) (n int, err os.Error) {
 	}
 	return
 }
+
+func CountCpus() int {
+	var contents [10240]byte
+	
+	f, err := os.Open("/proc/stat", os.O_RDONLY, 0)
+	defer f.Close()
+	if err != nil {
+		return 1 
+	}
+	n, _ := f.Read(contents[:])
+	re, _ := regexp.Compile("\ncpu[0-9]")
+	
+	return len(re.FindAllString(string(contents[:n]), 100))
+}