minor speedup

b979d25a · Nickolai Zeldovich · 44c54e3d · b979d25a
--- a/kernel/vm.cc
+++ b/kernel/vm.cc
@@ -25,7 +25,7 @@ vmnode::vmnode(u64 npg, vmntype ntype, inode *i, u64 off, u64 s)
 {
  if (npg > NELEM(page))
    panic("vmnode too big\n");
-  memset(page, 0, sizeof(page));
+  memset(page, 0, npg * sizeof(page[0]));
  if (type == EAGER) {
    assert(allocpg() == 0);
    if (ip)
@@ -35,12 +35,9 @@ vmnode::vmnode(u64 npg, vmntype ntype, inode *i, u64 off, u64 s)
 vmnode::~vmnode()
 {
-  for(u64 i = 0; i < npages; i++) {
+  for(u64 i = 0; i < npages; i++)
-    if (page[i]) {
+    if (page[i])
      kfree(page[i]);
-      page[i] = 0;
-    }
-  }
  if (ip)
    iput(ip);
 }