Define os.PageSize and syscall.PageSize.

R=rsc
APPROVED=rsc
DELTA=13  (13 added, 0 deleted, 0 changed)
OCL=29429
CL=29819

src/lib/os/types.go

@@ -9,6 +9,11 @@ import "syscall"
 // An operating-system independent representation of Unix data structures.
 // OS-specific routines in this directory convert the OS-local versions to these.
 
+// Getpagesize returns the underlying system's memory page size.
+func Getpagesize() int{
+	return syscall.Getpagesize()
+}
+
 // A Dir describes a file and is returned by Stat, Fstat, and Lstat
 type Dir struct {
 	Dev	uint64;	// device number of file system holding file.

src/lib/syscall/syscall_darwin_amd64.go

@@ -6,6 +6,10 @@ package syscall
 
 import "syscall"
 
+func Getpagesize() int {
+	return 4096
+}
+
 func TimespecToNsec(ts Timespec) int64 {
 	return int64(ts.Sec)*1e9 + int64(ts.Nsec);
 }

src/lib/syscall/syscall_linux_amd64.go

@@ -6,6 +6,10 @@ package syscall
 
 import "syscall"
 
+func Getpagesize() int {
+	return 4096
+}
+
 func TimespecToNsec(ts Timespec) int64 {
 	return int64(ts.Sec)*1e9 + int64(ts.Nsec);
 }