Great speedup ttread, if !(ICANON | ISIG), from bde.

diff --git a/sys/kern/tty.c b/sys/kern/tty.c
index 294ca4c..b07e7cc 100644 (file)
--- a/sys/kern/tty.c
+++ b/sys/kern/tty.c
@@ -32,7 +32,7 @@
  * SUCH DAMAGE.
  *
  *     from: @(#)tty.c 7.44 (Berkeley) 5/28/91
  * SUCH DAMAGE.
  *
  *     from: @(#)tty.c 7.44 (Berkeley) 5/28/91

- *     $Id: tty.c,v 1.11 1993/12/19 00:51:38 wollman Exp $
+ *     $Id: tty.c,v 1.12 1993/12/30 05:27:01 davidg Exp $

  */
 
 #include "param.h"
  */
 
 #include "param.h"


@@ -1294,14 +1294,17 @@ loop:
        /*
         * take pending input first 
         */
        /*
         * take pending input first 
         */

-       if (lflag&PENDIN)
+       if (lflag&PENDIN) {

                ttypend(tp);
                ttypend(tp);

-       splx(s);
+               splx(s);        /* reduce latency */
+               s = spltty();
+       }

 
        /*
         * Hang process if it's in the background.
         */
        if (isbackground(p, tp)) {
 
        /*
         * Hang process if it's in the background.
         */
        if (isbackground(p, tp)) {

+               splx(s);

                if ((p->p_sigignore & sigmask(SIGTTIN)) ||
                   (p->p_sigmask & sigmask(SIGTTIN)) ||
                    p->p_flag&SPPWAIT || p->p_pgrp->pg_jobc == 0)
                if ((p->p_sigignore & sigmask(SIGTTIN)) ||
                   (p->p_sigmask & sigmask(SIGTTIN)) ||
                    p->p_flag&SPPWAIT || p->p_pgrp->pg_jobc == 0)


@@ -1325,7 +1328,6 @@ loop:
         * awaiting hardware receipt and notification.
         * If we have data, we don't need to check for carrier.
         */
         * awaiting hardware receipt and notification.
         * If we have data, we don't need to check for carrier.
         */

-       s = spltty();

        if (RB_LEN(qp) <= not_enough) {
                int carrier;
 
        if (RB_LEN(qp) <= not_enough) {
                int carrier;
 


@@ -1351,13 +1353,45 @@ loop:
                        return (error);
                goto loop;
        }
                        return (error);
                goto loop;
        }

-       splx(s);

 
        /*
         * Input present, check for input mapping and processing.
         */
        first = 1;
 
        /*
         * Input present, check for input mapping and processing.
         */
        first = 1;

-       while ((c = getc(qp)) >= 0) {
+       if (lflag & (ICANON | ISIG))
+               goto slowcase;
+       for (;;) {
+               int rcc;
+
+               rcc = RB_CONTIGGET(qp);
+               if (rcc > uio->uio_resid)
+                       rcc = uio->uio_resid;
+               if (rcc <= 0) {
+                       if (first) {
+                               /* queue got flushed (can't happen) */
+                               splx(s);
+                               goto loop;
+                       }
+                       break;
+               }
+               error = uiomove(qp->rb_hd, rcc, uio);
+               if (error)
+                       splx(s);
+               qp->rb_hd = RB_ROLLOVER(qp, qp->rb_hd + rcc);
+               splx(s);
+               s = spltty();
+               first = 0;
+       }
+       goto out;
+slowcase:
+       for (;;) {
+               c = getc(qp);
+               splx(s);
+               if (c < 0) {
+                       if (first)
+                               goto loop;
+                       break;
+               }

                /*
                 * delayed suspend (^Y)
                 */
                /*
                 * delayed suspend (^Y)
                 */


@@ -1390,16 +1424,21 @@ loop:
                 */
                if (lflag&ICANON && ttbreakc(c))
                        break;
                 */
                if (lflag&ICANON && ttbreakc(c))
                        break;

+               s = spltty();

                first = 0;
        }
                first = 0;
        }

+       s = spltty();
+

        /*
         * Look to unblock input now that (presumably)
         * the input queue has gone down.
         */
        /*
         * Look to unblock input now that (presumably)
         * the input queue has gone down.
         */

+out:

        if (tp->t_state & (TS_TBLOCK | TS_HW_IFLOW)
            && INPUT_LEN(tp) <= I_LOW_WATER)
                ttyunblock(tp);
 
        if (tp->t_state & (TS_TBLOCK | TS_HW_IFLOW)
            && INPUT_LEN(tp) <= I_LOW_WATER)
                ttyunblock(tp);
 

+       splx(s);

        return (error);
 }
 
        return (error);
 }