Hopefully fix the "calcru: runtime went backwards from ..." problem by

keeping the resource values locked (where needed) while we use them
for calculations.

MFC after:	3 days

2 files changed, 4 insertions, 3 deletions

diff --git a/sys/kern/kern_exit.c b/sys/kern/kern_exit.c
index 56f800f..38e0131 100644
--- a/sys/kern/kern_exit.c
+++ b/sys/kern/kern_exit.c
@@ -437,14 +437,13 @@ retry:
 
 	/*
 	 * Save exit status and finalize rusage info except for times,
-	 * adding in child rusage info.
+	 * adding in child rusage info later when our time is locked.
 	 */
 	PROC_LOCK(p);
 	p->p_xstat = rv;
 	p->p_xthread = td;
 	p->p_stats->p_ru.ru_nvcsw++;
 	*p->p_ru = p->p_stats->p_ru;
-	ruadd(p->p_ru, &p->p_rux, &p->p_stats->p_cru, &p->p_crux);
 
 	/*
 	 * Notify interested parties of our demise.
@@ -531,6 +530,8 @@ retry:
 	p->p_state = PRS_ZOMBIE;
 	PROC_UNLOCK(p->p_pptr);
 
+	ruadd(p->p_ru, &p->p_rux, &p->p_stats->p_cru, &p->p_crux);
+
 	/* Do the same timestamp bookkeeping that mi_switch() would do. */
 	binuptime(&new_switchtime);
 	bintime_add(&p->p_rux.rux_runtime, &new_switchtime);
diff --git a/sys/kern/kern_resource.c b/sys/kern/kern_resource.c
index 397a7c5..ccfa07e 100644
--- a/sys/kern/kern_resource.c
+++ b/sys/kern/kern_resource.c
@@ -733,8 +733,8 @@ calcru(p, up, sp)
 			    &pcpu_find(td->td_oncpu)->pc_switchtime);
 		}
 	}
-	mtx_unlock_spin(&sched_lock);
 	calcru1(p, &rux, up, sp);
+	mtx_unlock_spin(&sched_lock);
 	p->p_rux.rux_uu = rux.rux_uu;
 	p->p_rux.rux_su = rux.rux_su;
 	p->p_rux.rux_iu = rux.rux_iu;