sched_peg_curproc_to_cpu() - function to force a proc to stay on a cpu

forever.

3 files changed, 31 insertions, 3 deletions

diff --git a/sys/kern/kern_sched.c b/sys/kern/kern_sched.c
index 1b921159985..29dd5793efe 100644
--- a/sys/kern/kern_sched.c
+++ b/sys/kern/kern_sched.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_sched.c,v 1.9 2009/03/23 13:25:11 art Exp $	*/
+/*	$OpenBSD: kern_sched.c,v 1.10 2009/04/03 09:29:15 art Exp $	*/
 /*
  * Copyright (c) 2007, 2008 Artur Grabowski <art@openbsd.org>
  *
@@ -291,6 +291,12 @@ sched_choosecpu(struct proc *p)
 	struct cpu_info *ci;
 	struct cpuset set;
 
+	/*
+	 * If pegged to a cpu, don't allow it to move.
+	 */
+	if (p->p_flag & P_CPUPEG)
+		return;
+
 	sched_choose++;
 
 	/*
@@ -482,6 +488,26 @@ sched_proc_to_cpu_cost(struct cpu_info *ci, struct proc *p)
 }
 
 /*
+ * Peg a proc to a cpu.
+ */
+void
+sched_peg_curproc(struct cpu_info *ci)
+{
+	struct proc *p = curproc;
+	int s;
+
+	SCHED_LOCK(s);
+	p->p_priority = p->p_usrpri;
+	p->p_stat = SRUN;
+	p->p_cpu = ci;
+	atomic_setbits_int(&p->p_flag, P_CPUPEG);
+	setrunqueue(p);
+	p->p_stats->p_ru.ru_nvcsw++;
+	mi_switch();
+	SCHED_UNLOCK(s);
+}
+
+/*
  * Functions to manipulate cpu sets.
  */
 struct cpu_info *cpuset_infos[MAXCPUS];
diff --git a/sys/sys/proc.h b/sys/sys/proc.h
index 2031c6f1870..2bfc6e308e5 100644
--- a/sys/sys/proc.h
+++ b/sys/sys/proc.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: proc.h,v 1.114 2009/03/26 17:24:33 oga Exp $	*/
+/*	$OpenBSD: proc.h,v 1.115 2009/04/03 09:29:15 art Exp $	*/
 /*	$NetBSD: proc.h,v 1.44 1996/04/22 01:23:21 christos Exp $	*/
 
 /*-
@@ -305,6 +305,7 @@ struct proc {
 #define	P_IGNEXITRV	0x8000000	/* For thread kills */
 #define	P_SOFTDEP	0x10000000	/* Stuck processing softdep worklist */
 #define P_STOPPED	0x20000000	/* Just stopped. */
+#define P_CPUPEG	0x40000000	/* Do not move to another cpu. */
 
 #define	P_BITS \
     ("\20\01ADVLOCK\02CTTY\04NOCLDSTOP\05PPWAIT\06PROFIL\07SELECT" \
diff --git a/sys/sys/sched.h b/sys/sys/sched.h
index 151adc9af37..7766f4da093 100644
--- a/sys/sys/sched.h
+++ b/sys/sys/sched.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: sched.h,v 1.20 2009/03/23 13:25:11 art Exp $	*/
+/*	$OpenBSD: sched.h,v 1.21 2009/04/03 09:29:15 art Exp $	*/
 /* $NetBSD: sched.h,v 1.2 1999/02/28 18:14:58 ross Exp $ */
 
 /*-
@@ -144,6 +144,7 @@ void sched_choosecpu(struct proc *);
 void cpu_idle_enter(void);
 void cpu_idle_cycle(void);
 void cpu_idle_leave(void);
+void sched_peg_curproc(struct cpu_info *ci);
 
 #define curcpu_is_idle()	(curcpu()->ci_schedstate.spc_whichqs == 0)