Eliminate the overhead of gratuitous repeated reinitialization of cap_rights

- Add macros to allow preinitialization of cap_rights_t.

- Convert most commonly used code paths to use preinitialized cap_rights_t.
  A 3.6% speedup in fstat was measured with this change.

Reported by:	mjg
Reviewed by:	oshogbo
Approved by:	sbruno
MFC after:	1 month

1 files changed, 5 insertions, 9 deletions

diff --git a/sys/kern/vfs_aio.c b/sys/kern/vfs_aio.c
index c82823f00274..69dd50cf7bdf 100644
--- a/sys/kern/vfs_aio.c
+++ b/sys/kern/vfs_aio.c
@@ -1450,7 +1450,6 @@ aio_aqueue(struct thread *td, struct aiocb *ujob, struct aioliojob *lj,
     int type, struct aiocb_ops *ops)
 {
 	struct proc *p = td->td_proc;
-	cap_rights_t rights;
 	struct file *fp;
 	struct kaiocb *job;
 	struct kaioinfo *ki;
@@ -1528,21 +1527,19 @@ aio_aqueue(struct thread *td, struct aiocb *ujob, struct aioliojob *lj,
 	fd = job->uaiocb.aio_fildes;
 	switch (opcode) {
 	case LIO_WRITE:
-		error = fget_write(td, fd,
-		    cap_rights_init(&rights, CAP_PWRITE), &fp);
+		error = fget_write(td, fd, &cap_pwrite_rights, &fp);
 		break;
 	case LIO_READ:
-		error = fget_read(td, fd,
-		    cap_rights_init(&rights, CAP_PREAD), &fp);
+		error = fget_read(td, fd, &cap_pread_rights, &fp);
 		break;
 	case LIO_SYNC:
-		error = fget(td, fd, cap_rights_init(&rights, CAP_FSYNC), &fp);
+		error = fget(td, fd, &cap_fsync_rights, &fp);
 		break;
 	case LIO_MLOCK:
 		fp = NULL;
 		break;
 	case LIO_NOP:
-		error = fget(td, fd, cap_rights_init(&rights), &fp);
+		error = fget(td, fd, &cap_no_rights, &fp);
 		break;
 	default:
 		error = EINVAL;
@@ -1959,14 +1956,13 @@ sys_aio_cancel(struct thread *td, struct aio_cancel_args *uap)
 	struct kaioinfo *ki;
 	struct kaiocb *job, *jobn;
 	struct file *fp;
-	cap_rights_t rights;
 	int error;
 	int cancelled = 0;
 	int notcancelled = 0;
 	struct vnode *vp;
 
 	/* Lookup file object. */
-	error = fget(td, uap->fd, cap_rights_init(&rights), &fp);
+	error = fget(td, uap->fd, &cap_no_rights, &fp);
 	if (error)
 		return (error);