Subject: network receive performance improvement (#131)
Index:	pdpif/if_uba.c 2.11BSD

Description:
	The receive routine 'if_rubaget' does not allocate a large
	mbuf when possible.

Repeat-By:
	Examination.  Note that the 3com driver (if_ec.c) does not
	call if_rubaget and implements its own "cluster" (large) mbuf
	allocation logic.

Fix:
	Apply the following patch.

	Using a DEQNA on a 11/73 this patch improved the 'ftp' performance
	by 12% when transferring a file to the 11/73.  

	A couple of register variable assignments were changed (there was
	an unused register variable in one function) to improve the code
	generated.
===========================cut here=================================
*** /sys/pdpif/if_uba.c.old	Sun Jan  3 00:52:53 1993
--- /sys/pdpif/if_uba.c	Sat Apr  3 21:13:32 1993
***************
*** 3,9 ****
   * All rights reserved.  The Berkeley software License Agreement
   * specifies the terms and conditions for redistribution.
   *
!  *	@(#)if_uba.c	1.1 (2.10BSD Berkeley) 12/1/86
   *
   *	2.11BSD - uballoc and ubmalloc calling conventions changed.
   *		  ubmalloc now only performs address computation, the
--- 3,9 ----
   * All rights reserved.  The Berkeley software License Agreement
   * specifies the terms and conditions for redistribution.
   *
!  *	@(#)if_uba.c	1.2 (2.11BSD GTE) 4/3/93
   *
   *	2.11BSD - uballoc and ubmalloc calling conventions changed.
   *		  ubmalloc now only performs address computation, the
***************
*** 85,90 ****
--- 85,99 ----
  			cp = (caddr_t) (ifu->ifu_hlen + off);
  		} else
  			len = totlen;
+ 		if (len >= NBPG) {
+ 			if (ifp)
+ 				goto nopage;
+ 			MCLGET(m);
+ 			if (m->m_len != CLBYTES)
+ 				goto nopage;
+ 			m->m_len = MIN(len, CLBYTES);
+ 			goto copy;
+ 		}
  nopage:
  		m->m_off = MMINOFF;
  		if (ifp) {
***************
*** 132,142 ****
   * header.
   */
  if_wubaput(ifu, m)
! 	register struct ifuba *ifu;
  	register struct mbuf *m;
  {
  	register struct mbuf *mp;
! 	u_short off = 0;
  	u_short click = ifu->ifu_w.ifrw_click;
  
  	while (m) {
--- 141,151 ----
   * header.
   */
  if_wubaput(ifu, m)
! 	struct ifuba *ifu;
  	register struct mbuf *m;
  {
  	register struct mbuf *mp;
! 	register u_short off = 0;
  	u_short click = ifu->ifu_w.ifrw_click;
  
  	while (m) {
***************
*** 162,168 ****
  	caddr_t addr;
  	u_int size;
  {
! 	register int nregs, s;
  	register struct ubmap *ubp;
  	ubadr_t paddr, vaddr;
  	u_int click, first;
--- 171,177 ----
  	caddr_t addr;
  	u_int size;
  {
! 	register int nregs;
  	register struct ubmap *ubp;
  	ubadr_t paddr, vaddr;
  	u_int click, first;
***************
*** 206,212 ****
   */
  ubadr_t
  ubmalloc(addr)
! 	register memaddr addr;		/* pdp11 "clicks" */
  {
  	extern ubadr_t mioumr;
  	extern memaddr miostart;
--- 215,221 ----
   */
  ubadr_t
  ubmalloc(addr)
! 	memaddr addr;		/* pdp11 "clicks" */
  {
  	extern ubadr_t mioumr;
  	extern memaddr miostart;