[src/trunk]: src/sys/kern Add a ttyprintf_nolock() to be called when we are p...

[christos <christos%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/f5b68e0639a7
branches:  trunk
changeset: 543124:f5b68e0639a7
user:      christos <christos%NetBSD.org@localhost>
date:      Mon Feb 17 22:23:14 2003 +0000

description:
Add a ttyprintf_nolock() to be called when we are printing the ttyinfo
stuff, since we already have the lock.
Adjust tputchar so that it does not lock, when NOLOCK is passed in flags.

diffstat:

 sys/kern/tty.c |  56 ++++++++++++++++++++++++++++++++++++++++----------------
 1 files changed, 40 insertions(+), 16 deletions(-)

diffs (147 lines):

diff -r 8c263fe3c94c -r f5b68e0639a7 sys/kern/tty.c
--- a/sys/kern/tty.c    Mon Feb 17 22:21:52 2003 +0000
+++ b/sys/kern/tty.c    Mon Feb 17 22:23:14 2003 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: tty.c,v 1.148 2003/02/06 12:21:21 pk Exp $     */
+/*     $NetBSD: tty.c,v 1.149 2003/02/17 22:23:14 christos Exp $       */
 
 /*-
  * Copyright (c) 1982, 1986, 1990, 1991, 1993
@@ -41,7 +41,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: tty.c,v 1.148 2003/02/06 12:21:21 pk Exp $");
+__KERNEL_RCSID(0, "$NetBSD: tty.c,v 1.149 2003/02/17 22:23:14 christos Exp $");
 
 #include "opt_uconsole.h"
 
@@ -64,11 +64,16 @@
 #include <sys/signalvar.h>
 #include <sys/resourcevar.h>
 #include <sys/poll.h>
+#include <sys/kprintf.h>
+
+#include <machine/stdarg.h>
 
 static int     ttnread(struct tty *);
 static void    ttyblock(struct tty *);
 static void    ttyecho(int, struct tty *);
 static void    ttyrubo(struct tty *, int);
+static void    ttyprintf_nolock(struct tty *, const char *fmt, ...)
+    __attribute__((__format__(__printf__,2,3)));
 static int     proc_compare(struct proc *, struct proc *);
 
 /* Symbolic sleep message strings. */
@@ -2203,23 +2208,23 @@
 
        /* Print load average. */
        tmp = (averunnable.ldavg[0] * 100 + FSCALE / 2) >> FSHIFT;
-       ttyprintf(tp, "load: %d.%02d ", tmp / 100, tmp % 100);
+       ttyprintf_nolock(tp, "load: %d.%02d ", tmp / 100, tmp % 100);
 
        if (tp->t_session == NULL)
-               ttyprintf(tp, "not a controlling terminal\n");
+               ttyprintf_nolock(tp, "not a controlling terminal\n");
        else if (tp->t_pgrp == NULL)
-               ttyprintf(tp, "no foreground process group\n");
+               ttyprintf_nolock(tp, "no foreground process group\n");
        else if ((p = LIST_FIRST(&tp->t_pgrp->pg_members)) == 0)
-               ttyprintf(tp, "empty foreground process group\n");
+               ttyprintf_nolock(tp, "empty foreground process group\n");
        else {
                /* Pick interesting process. */
                for (pick = NULL; p != NULL; p = LIST_NEXT(p, p_pglist))
                        if (proc_compare(pick, p))
                                pick = p;
 
-               ttyprintf(tp, " cmd: %s %d [", pick->p_comm, pick->p_pid);
+               ttyprintf_nolock(tp, " cmd: %s %d [", pick->p_comm, pick->p_pid);
                LIST_FOREACH(l, &pick->p_lwps, l_sibling)
-                   ttyprintf(tp, "%s%s",
+                   ttyprintf_nolock(tp, "%s%s",
                    l->l_stat == LSONPROC ? "running" :
                    l->l_stat == LSRUN ? "runnable" :
                    l->l_wmesg ? l->l_wmesg : "iowait",
@@ -2233,7 +2238,7 @@
                        utime.tv_sec += 1;
                        utime.tv_usec -= 1000000;
                }
-               ttyprintf(tp, "%ld.%02ldu ", (long int)utime.tv_sec,
+               ttyprintf_nolock(tp, "%ld.%02ldu ", (long int)utime.tv_sec,
                    (long int)utime.tv_usec / 10000);
 
                /* Round up and print system time. */
@@ -2242,13 +2247,13 @@
                        stime.tv_sec += 1;
                        stime.tv_usec -= 1000000;
                }
-               ttyprintf(tp, "%ld.%02lds ", (long int)stime.tv_sec,
+               ttyprintf_nolock(tp, "%ld.%02lds ", (long int)stime.tv_sec,
                    (long int)stime.tv_usec / 10000);
 
 #define        pgtok(a)        (((u_long) ((a) * PAGE_SIZE) / 1024))
                /* Print percentage cpu. */
                tmp = (pick->p_pctcpu * 10000 + FSCALE / 2) >> FSHIFT;
-               ttyprintf(tp, "%d%% ", tmp / 100);
+               ttyprintf_nolock(tp, "%d%% ", tmp / 100);
 
                /* Print resident set size. */
                if (pick->p_stat == SIDL || P_ZOMBIE(pick))
@@ -2257,7 +2262,7 @@
                        struct vmspace *vm = pick->p_vmspace;
                        tmp = pgtok(vm_resident_count(vm));
                }
-               ttyprintf(tp, "%dk\n", tmp);
+               ttyprintf_nolock(tp, "%dk\n", tmp);
        }
        tp->t_rocount = 0;      /* so pending input will be retyped if BS */
 }
@@ -2340,12 +2345,13 @@
  * Can be called with tty lock held through kprintf() machinery..
  */
 int
-tputchar(int c, struct tty *tp)
+tputchar(int c, int flags, struct tty *tp)
 {
-       int     release_lock, s, r = 0;
+       int s, r = 0;
 
        s = spltty();
-       release_lock = simple_lock_try(&tp->t_slock);
+       if ((flags & NOLOCK) == 0)
+               simple_lock(&tp->t_slock);
        if (!CONNECTED(tp)) {
                r = -1;
                goto out;
@@ -2355,7 +2361,7 @@
        (void)ttyoutput(c, tp);
        ttstart(tp);
 out:
-       if (release_lock)
+       if ((flags & NOLOCK) == 0)
                TTY_UNLOCK(tp);
        splx(s);
        return (r);
@@ -2474,3 +2480,21 @@
        clfree(&tp->t_outq);
        pool_put(&tty_pool, tp);
 }
+
+/*
+ * ttyprintf_nolock: send a message to a specific tty, without locking.
+ *
+ * => should be used only by tty driver or anything that knows the
+ *    underlying tty will not be revoked(2)'d away.  [otherwise,
+ *    use tprintf]
+ */
+static void
+ttyprintf_nolock(struct tty *tp, const char *fmt, ...)
+{
+       va_list ap;
+
+       /* No mutex needed; going to process TTY. */
+       va_start(ap, fmt);
+       kprintf(fmt, TOTTY|NOLOCK, tp, NULL, ap);
+       va_end(ap);
+}