diff options
| author | Theo de Raadt <deraadt@cvs.openbsd.org> | 1999-08-04 19:18:14 +0000 |
|---|---|---|
| committer | Theo de Raadt <deraadt@cvs.openbsd.org> | 1999-08-04 19:18:14 +0000 |
| commit | 5c1fabdc6905c56357a34f53e52df5bd923e36c8 (patch) | |
| tree | ca042973caf021ac33d0dd3705d173a050cd2b32 | |
| parent | 2307bb91f2e40e22872556cf51d7ba9f15527e4d (diff) | |
optimize poll() for small nfds, by avoiding malloc
| -rw-r--r-- | sys/kern/sys_generic.c | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/sys/kern/sys_generic.c b/sys/kern/sys_generic.c index 6e6f19d4be1..2cc5a66e27f 100644 --- a/sys/kern/sys_generic.c +++ b/sys/kern/sys_generic.c @@ -1,4 +1,4 @@ -/* $OpenBSD: sys_generic.c,v 1.19 1999/05/24 17:18:52 deraadt Exp $ */ +/* $OpenBSD: sys_generic.c,v 1.20 1999/08/04 19:18:13 deraadt Exp $ */ /* $NetBSD: sys_generic.c,v 1.24 1996/03/29 00:25:32 cgd Exp $ */ /* @@ -810,7 +810,7 @@ sys_poll(p, v, retval) { struct sys_poll_args *uap = v; size_t sz; - struct pollfd *pl; + struct pollfd pfds[4], *pl = pfds; int msec = SCARG(uap, timeout); struct timeval atv; int timo, ncoll, i, s, error, error2; @@ -821,7 +821,9 @@ sys_poll(p, v, retval) SCARG(uap, nfds) = p->p_fd->fd_nfiles; sz = sizeof(struct pollfd) * SCARG(uap, nfds); - pl = (struct pollfd *) malloc(sz, M_TEMP, M_WAITOK); + /* optimize for the default case, of a small nfds value */ + if (sz > sizeof(pfds)) + pl = (struct pollfd *) malloc(sz, M_TEMP, M_WAITOK); if ((error = copyin(SCARG(uap, fds), pl, sz)) != 0) goto bad; @@ -880,6 +882,7 @@ done: if ((error2 = copyout(pl, SCARG(uap, fds), sz)) != 0) error = error2; bad: - free((char *) pl, M_TEMP); + if (pl != pfds) + free((char *) pl, M_TEMP); return (error); } |