MFcalloutng (r244249, r244306 by mav):

- Switch syscons from timeout() to callout_reset_flags() and specify that
precision is not important there -- anything from 20 to 30Hz will be fine.
- Reduce syscons "refresh" rate to 1-2Hz when console is in graphics mode
and there is nothing to do except some polling for keyboard.  Text mode
refresh would also be nice to have adaptive, but this change at least
should help laptop users who running X.

Sponsored by:	Google Summer of Code 2012, iXsystems inc.
Tested by:	flo, marius, ian, markj, Fabian Keil

2 files changed, 32 insertions, 28 deletions

diff --git a/sys/dev/syscons/syscons.c b/sys/dev/syscons/syscons.c
index 8094ea3..b863f90 100644
--- a/sys/dev/syscons/syscons.c
+++ b/sys/dev/syscons/syscons.c
@@ -506,6 +506,8 @@ sc_attach_unit(int unit, int flags)
 
     sc = sc_get_softc(unit, flags & SC_KERNEL_CONSOLE);
     sc->config = flags;
+    callout_init(&sc->ctimeout, 0);
+    callout_init(&sc->cblink, 0);
     scp = sc_get_stat(sc->dev[0]);
     if (sc_console == NULL)	/* sc_console_unit < 0 */
 	sc_console = scp;
@@ -1831,13 +1833,11 @@ static void
 scrn_timer(void *arg)
 {
 #ifndef PC98
-    static int kbd_interval = 0;
+    static time_t kbd_time_stamp = 0;
 #endif
-    struct timeval tv;
     sc_softc_t *sc;
     scr_stat *scp;
-    int again;
-    int s;
+    int again, rate;
 
     again = (arg != NULL);
     if (arg != NULL)
@@ -1847,18 +1847,18 @@ scrn_timer(void *arg)
     else
 	return;
 
+    /* find the vty to update */
+    scp = sc->cur_scp;
+
     /* don't do anything when we are performing some I/O operations */
-    if (suspend_in_progress || sc->font_loading_in_progress) {
-	if (again)
-	    timeout(scrn_timer, sc, hz / 10);
-	return;
-    }
-    s = spltty();
+    if (suspend_in_progress || sc->font_loading_in_progress)
+	goto done;
 
 #ifndef PC98
     if ((sc->kbd == NULL) && (sc->config & SC_AUTODETECT_KBD)) {
 	/* try to allocate a keyboard automatically */
-	if (++kbd_interval >= 25) {
+	if (kbd_time_stamp != time_uptime) {
+	    kbd_time_stamp = time_uptime;
 	    sc->keyboard = sc_allocate_keyboard(sc, -1);
 	    if (sc->keyboard >= 0) {
 		sc->kbd = kbd_get_keyboard(sc->keyboard);
@@ -1867,25 +1867,20 @@ scrn_timer(void *arg)
 		update_kbd_state(sc->cur_scp, sc->cur_scp->status,
 				 LOCK_MASK);
 	    }
-	    kbd_interval = 0;
 	}
     }
 #endif /* PC98 */
 
-    /* find the vty to update */
-    scp = sc->cur_scp;
-
     /* should we stop the screen saver? */
-    getmicrouptime(&tv);
     if (debugger > 0 || panicstr || shutdown_in_progress)
 	sc_touch_scrn_saver();
     if (run_scrn_saver) {
-	if (tv.tv_sec > sc->scrn_time_stamp + scrn_blank_time)
+	if (time_uptime > sc->scrn_time_stamp + scrn_blank_time)
 	    sc->flags |= SC_SCRN_IDLE;
 	else
 	    sc->flags &= ~SC_SCRN_IDLE;
     } else {
-	sc->scrn_time_stamp = tv.tv_sec;
+	sc->scrn_time_stamp = time_uptime;
 	sc->flags &= ~SC_SCRN_IDLE;
 	if (scrn_blank_time > 0)
 	    run_scrn_saver = TRUE;
@@ -1898,12 +1893,8 @@ scrn_timer(void *arg)
 
     /* should we just return ? */
     if (sc->blink_in_progress || sc->switch_in_progress
-	|| sc->write_in_progress) {
-	if (again)
-	    timeout(scrn_timer, sc, hz / 10);
-	splx(s);
-	return;
-    }
+	|| sc->write_in_progress)
+	goto done;
 
     /* Update the screen */
     scp = sc->cur_scp;		/* cur_scp may have changed... */
@@ -1917,9 +1908,19 @@ scrn_timer(void *arg)
 	    (*current_saver)(sc, TRUE);
 #endif
 
-    if (again)
-	timeout(scrn_timer, sc, hz / 25);
-    splx(s);
+done:
+    if (again) {
+	/*
+	 * Use reduced "refresh" rate if we are in graphics and that is not a
+	 * graphical screen saver.  In such case we just have nothing to do.
+	 */
+	if (ISGRAPHSC(scp) && !(sc->flags & SC_SCRN_BLANKED))
+	    rate = 2;
+	else
+	    rate = 30;
+	callout_reset_sbt(&sc->ctimeout, SBT_1S / rate, 0,
+	    scrn_timer, sc, C_PREL(1));
+    }
 }
 
 static int
@@ -3863,7 +3864,8 @@ blink_screen(void *arg)
 	(*scp->rndr->draw)(scp, 0, scp->xsize*scp->ysize, 
 			   scp->sc->blink_in_progress & 1);
 	scp->sc->blink_in_progress--;
-	timeout(blink_screen, scp, hz / 10);
+	callout_reset_sbt(&scp->sc->cblink, SBT_1S / 15, 0,
+	    blink_screen, scp, C_PREL(0));
     }
 }
 
diff --git a/sys/dev/syscons/syscons.h b/sys/dev/syscons/syscons.h
index 23a7bba..353b67f 100644
--- a/sys/dev/syscons/syscons.h
+++ b/sys/dev/syscons/syscons.h
@@ -269,6 +269,8 @@ typedef struct sc_softc {
 #ifdef KDB
 	int		sc_altbrk;
 #endif
+	struct callout	ctimeout;
+	struct callout	cblink;
 } sc_softc_t;
 
 /* virtual screen */