From 409b865291e53eb3a52f2f39867fedea3be9aab0 Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Tue, 20 Sep 1994 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1994-09-20

---
 port/portdat.h |  1 +
 port/proc.c    | 20 ++++++++++++++++----
 2 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/port/portdat.h b/port/portdat.h
index 664d9590035dbc4e66881e45577cc2862170d1dd..d1f953ed0087843e2311bac2bcd47ef9d880f6e1 100644
--- a/port/portdat.h
+++ b/port/portdat.h
@@ -502,6 +502,7 @@ enum
 
 	Nrq		= 20,	/* number of scheduler priority levels */
 	PriNormal	= 10,	/* base priority for normal processes */
+	PriKproc	= 13,	/* base priority for kernel processes */
 	PriRoot		= 13,	/* base priority for root processes */
 };
 
diff --git a/port/proc.c b/port/proc.c
index 8d934f71c875ecaa3199ef71c67c630b53a986b1..5b528c4b483faa87d75882dca22626a1c9d5b0cb 100644
--- a/port/proc.c
+++ b/port/proc.c
@@ -137,11 +137,22 @@ ready(Proc *p)
 
 	s = splhi();
 
-	if(p->state == Running)
+	/* history counts */
+	if(p->state == Running){
 		p->rt++;
-	pri = p->basepri - (((p->art + p->rt)>>1)/Squantum);
+		pri = ((p->art + (p->rt<<1))>>2)/Squantum;
+	} else {
+		p->art = (p->art + (p->rt<<1))>>2;
+		p->rt = 0;
+		pri = p->art/Squantum;
+	}
+	pri = p->basepri - pri;
 	if(pri < 0)
 		pri = 0;
+
+	/* the only intersection between the classes is at PriNormal */
+	if(pri < PriNormal && p->basepri > PriNormal)
+		pri = PriNormal;
 	p->priority = pri;
 	rq = &runq[p->priority];
 
@@ -364,8 +375,6 @@ sleep1(Rendez *r, int (*f)(void*), void *arg)
 		dumpstack();
 	}
 	up->state = Wakeme;
-	up->art = (up->art + up->rt)>>1;
-	up->rt = 0;
 	r->p = up;
 	unlock(r);
 }
@@ -812,6 +821,9 @@ kproc(char *name, void (*func)(void *), void *arg)
 	p->ureg = 0;
 	p->dbgreg = 0;
 
+	p->basepri = PriKproc;
+	p->priority = p->basepri;
+
 	kprocchild(p, func, arg);
 
 	strcpy(p->user, eve);