kern/65857: sched_ule.c doesn't honor P_NOLOAD, leading to high (by one) vm.loadavg

[Nikos Ntarmos]

>Number:         65857
>Category:       kern
>Synopsis:       sched_ule.c doesn't honor P_NOLOAD, leading to high (by one) vm.loadavg
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Wed Apr 21 11:00:38 PDT 2004
>Closed-Date:
>Last-Modified:
>Originator:     Nikos Ntarmos
>Release:        FreeBSD 5.2-CURRENT alpha
>Organization:
NetCINS Lab - CEID - UPatras - Greece
>Environment:
System: FreeBSD Gatekeeper.ceid.upatras.gr 5.2-CURRENT FreeBSD 5.2-CURRENT #11: Wed Apr 21 03:22:39 EEST 2004 root at Gatekeeper.ceid.upatras.gr:/usr/obj/usr/src/sys/GATEKEEPER alpha


	
>Description:
	sched_ule.c doesn't honor P_NOLOAD. This results in the system
	load being reported as "expected-load-plus-one", also refernced
	in a current@ thread back in January 2004. This is ULE-specific.
	
>How-To-Repeat:
	Just run CURRENT with 'options SCHED_ULE' and see the system load
	(as reported by vm.loadavg or userland tools such as top) hovering
	to 1.00 for an idle system, or to "expected-load-plus-one" in general.
	
>Fix:
--- sys/kern/sched_ule.c.orig   Wed Apr 21 03:10:29 2004
+++ sys/kern/sched_ule.c        Wed Apr 21 03:20:34 2004
@@ -357,7 +357,7 @@
        if (class == PRI_TIMESHARE)
                kseq->ksq_load_timeshare++;
        kseq->ksq_load++;
-       if (class != PRI_ITHD)
+       if (class != PRI_ITHD && (ke->ke_proc->p_flag & P_NOLOAD) == 0)
 #ifdef SMP
                kseq->ksq_group->ksg_load++;
 #else
@@ -380,7 +380,7 @@
        class = PRI_BASE(ke->ke_ksegrp->kg_pri_class);
        if (class == PRI_TIMESHARE)
                kseq->ksq_load_timeshare--;
-       if (class != PRI_ITHD)
+       if (class != PRI_ITHD  && (ke->ke_proc->p_flag & P_NOLOAD) == 0)
 #ifdef SMP
                kseq->ksq_group->ksg_load--;
 #else
>Release-Note:
>Audit-Trail:
>Unformatted: