Module Name: src
Committed By: christos
Date: Fri Oct 21 02:08:10 UTC 2011
Modified Files:
src/sys/kern: tty.c
Log Message:
extract broken proc_compare. lwp compares against self.
To generate a diff of this commit:
cvs rdiff -u -r1.248 -r1.249 src/sys/kern/tty.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/kern/tty.c
diff -u src/sys/kern/tty.c:1.248 src/sys/kern/tty.c:1.249
--- src/sys/kern/tty.c:1.248 Fri Sep 23 20:05:38 2011
+++ src/sys/kern/tty.c Thu Oct 20 22:08:09 2011
@@ -1,4 +1,4 @@
-/* $NetBSD: tty.c,v 1.248 2011/09/24 00:05:38 christos Exp $ */
+/* $NetBSD: tty.c,v 1.249 2011/10/21 02:08:09 christos Exp $ */
/*-
* Copyright (c) 2008 The NetBSD Foundation, Inc.
@@ -63,7 +63,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: tty.c,v 1.248 2011/09/24 00:05:38 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: tty.c,v 1.249 2011/10/21 02:08:09 christos Exp $");
#include <sys/param.h>
#include <sys/systm.h>
@@ -99,7 +99,7 @@ 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 *);
+static int proc_compare_wrapper(struct proc *, struct proc *);
static void ttysigintr(void *);
/* Symbolic sleep message strings. */
@@ -2488,7 +2488,7 @@ ttygetinfo(struct tty *tp, int fromsig,
} else
mutex_enter(p->p_lock);
oldpick = pick;
- if (proc_compare(pick, p))
+ if (proc_compare_wrapper(pick, p))
pick = p;
mutex_exit(p->p_lock);
if (p->p_lock != oldpick->p_lock)
@@ -2594,26 +2594,11 @@ ttyputinfo(struct tty *tp, char *buf)
}
/*
- * Returns 1 if p2 is "better" than p1
- *
- * The algorithm for picking the "interesting" process is thus:
- *
- * 1) Only foreground processes are eligible - implied.
- * 2) Runnable processes are favored over anything else. The runner
- * with the highest CPU utilization is picked (l_pctcpu). Ties are
- * broken by picking the highest pid.
- * 3) The sleeper with the shortest sleep time is next. With ties,
- * we pick out just "short-term" sleepers (P_SINTR == 0).
- * 4) Further ties are broken by picking the highest pid.
- */
-#define ISRUN(p) ((p)->p_nrlwps > 0)
-#define TESTAB(a, b) ((a)<<1 | (b))
-#define ONLYA 2
-#define ONLYB 1
-#define BOTH 3
-
+ * Returns 1 if p2 has a better chance being the active foreground process
+ * in a terminal instead of p1.
+ */
static int
-proc_compare(struct proc *p1, struct proc *p2)
+proc_compare_wrapper(struct proc *p1, struct proc *p2)
{
lwp_t *l1, *l2;
@@ -2621,51 +2606,12 @@ proc_compare(struct proc *p1, struct pro
KASSERT(mutex_owned(p2->p_lock));
if ((l1 = LIST_FIRST(&p1->p_lwps)) == NULL)
- return (1);
+ return 1;
+
if ((l2 = LIST_FIRST(&p2->p_lwps)) == NULL)
- return (0);
- /*
- * see if at least one of them is runnable
- */
- switch (TESTAB(ISRUN(p1), ISRUN(p2))) {
- case ONLYA:
- return (0);
- case ONLYB:
- return (1);
- case BOTH:
- /*
- * tie - favor one with highest recent CPU utilization
- */
- if (l2->l_pctcpu > l1->l_pctcpu)
- return (1);
- return (p2->p_pid > p1->p_pid); /* tie - return highest pid */
- }
- /*
- * weed out zombies
- */
- switch (TESTAB(P_ZOMBIE(p1), P_ZOMBIE(p2))) {
- case ONLYA:
- return (1);
- case ONLYB:
- return (0);
- case BOTH:
- return (p2->p_pid > p1->p_pid); /* tie - return highest pid */
- }
- /*
- * pick the one with the smallest sleep time
- */
- if (l2->l_slptime > l2->l_slptime)
- return (0);
- if (l2->l_slptime > l2->l_slptime)
- return (1);
- /*
- * favor one sleeping in a non-interruptible sleep
- */
- if (l2->l_flag & LW_SINTR && (l2->l_flag & LW_SINTR) == 0)
- return (1);
- if (l2->l_flag & LW_SINTR && (l2->l_flag & LW_SINTR) == 0)
- return (0);
- return (p2->p_pid > p1->p_pid); /* tie - return highest pid */
+ return 0;
+
+ return proc_compare(p1, l1, p2, l2);
}
/*
