- Redefine p_swtime and td_slptime as p_swtick and td_slptick. This

   changes the units from seconds to the value of 'ticks' when swapped
   in/out.  ULE does not have a periodic timer that scans all threads in
   the system and as such maintaining a per-second counter is difficult.
 - Change computations requiring the unit in seconds to subtract ticks
   and divide by hz.  This does make the wraparound condition hz times
   more frequent but this is still in the range of several months to
   years and the adverse effects are minimal.

Approved by:    re

1 files changed, 14 insertions, 9 deletions

diff --git a/sys/vm/vm_glue.c b/sys/vm/vm_glue.c
index 6e4f42d..caa8aa0 100644
--- a/sys/vm/vm_glue.c
+++ b/sys/vm/vm_glue.c
@@ -636,7 +636,7 @@ faultin(p)
 		PROC_LOCK(p);
 		PROC_SLOCK(p);
 		swapclear(p);
-		p->p_swtime = 0;
+		p->p_swtick = ticks;
 		PROC_SUNLOCK(p);
 
 		wakeup(&p->p_flag);
@@ -663,9 +663,11 @@ scheduler(dummy)
 {
 	struct proc *p;
 	struct thread *td;
-	int pri;
 	struct proc *pp;
+	int slptime;
+	int swtime;
 	int ppri;
+	int pri;
 
 	mtx_assert(&Giant, MA_OWNED | MA_NOTRECURSED);
 	mtx_unlock(&Giant);
@@ -688,6 +690,7 @@ loop:
 			PROC_UNLOCK(p);
 			continue;
 		}
+		swtime = (ticks - p->p_swtick) / hz;
 		PROC_SLOCK(p);
 		FOREACH_THREAD_IN_PROC(p, td) {
 			/*
@@ -697,7 +700,8 @@ loop:
 			 */
 			thread_lock(td);
 			if (td->td_inhibitors == TDI_SWAPPED) {
-				pri = p->p_swtime + td->td_slptime;
+				slptime = (ticks - td->td_slptick) / hz;
+				pri = swtime + slptime;
 				if ((td->td_flags & TDF_SWAPINREQ) == 0)
 					pri -= p->p_nice * 8;
 				/*
@@ -816,6 +820,7 @@ retry:
 	FOREACH_PROC_IN_SYSTEM(p) {
 		struct vmspace *vm;
 		int minslptime = 100000;
+		int slptime;
 		
 		/*
 		 * Watch out for a process in
@@ -882,12 +887,12 @@ retry:
 					thread_unlock(td);
 					goto nextproc;
 				}
-
+				slptime = (ticks - td->td_slptick) / hz;
 				/*
 				 * Guarantee swap_idle_threshold1
 				 * time in memory.
 				 */
-				if (td->td_slptime < swap_idle_threshold1) {
+				if (slptime < swap_idle_threshold1) {
 					thread_unlock(td);
 					goto nextproc;
 				}
@@ -914,13 +919,13 @@ retry:
 				 */
 				if (((action & VM_SWAP_NORMAL) == 0) &&
 				    (((action & VM_SWAP_IDLE) == 0) ||
-				    (td->td_slptime < swap_idle_threshold2))) {
+				    (slptime < swap_idle_threshold2))) {
 					thread_unlock(td);
 					goto nextproc;
 				}
 
-				if (minslptime > td->td_slptime)
-					minslptime = td->td_slptime;
+				if (minslptime > slptime)
+					minslptime = slptime;
 				thread_unlock(td);
 			}
 
@@ -1038,7 +1043,7 @@ swapout(p)
 	PROC_LOCK(p);
 	p->p_flag &= ~P_SWAPPINGOUT;
 	PROC_SLOCK(p);
-	p->p_swtime = 0;
+	p->p_swtick = ticks;
 	return (0);
 }
 #endif /* !NO_SWAPPING */