6577453 Java CPU hogs can escape CPU Caps enforcement by sleeping a lot

3 files changed, 28 insertions, 9 deletions

diff --git a/usr/src/uts/common/disp/fss.c b/usr/src/uts/common/disp/fss.c
index a409ebc800..e132ff3397 100644
--- a/usr/src/uts/common/disp/fss.c
+++ b/usr/src/uts/common/disp/fss.c
@@ -1799,6 +1799,13 @@ fss_exit(kthread_t *t)
 	mutex_exit(&fsspset->fssps_lock);
 	mutex_exit(&fsspsets_lock);
 
+	/*
+	 * A thread could be exiting in between clock ticks, so we need to
+	 * calculate how much CPU time it used since it was charged last time.
+	 *
+	 * CPU caps are not enforced on exiting processes - it is usually
+	 * desirable to exit as soon as possible to free resources.
+	 */
 	if (CPUCAPS_ON()) {
 		thread_lock(t);
 		fssproc = FSSPROC(t);
@@ -1993,7 +2000,7 @@ fss_preempt(kthread_t *t)
 	 */
 	if (CPUCAPS_ON()) {
 		(void) cpucaps_charge(t, &fssproc->fss_caps,
-		    CPUCAPS_CHARGE_ONLY);
+		    CPUCAPS_CHARGE_ENFORCE);
 
 		if (!(fssproc->fss_flags & FSSKPRI) && CPUCAPS_ENFORCE(t))
 			return;
@@ -2109,7 +2116,7 @@ fss_sleep(kthread_t *t)
 	/*
 	 * Account for time spent on CPU before going to sleep.
 	 */
-	(void) CPUCAPS_CHARGE(t, &fssproc->fss_caps, CPUCAPS_CHARGE_ONLY);
+	(void) CPUCAPS_CHARGE(t, &fssproc->fss_caps, CPUCAPS_CHARGE_ENFORCE);
 
 	fss_inactive(t);
 
@@ -2412,7 +2419,7 @@ fss_yield(kthread_t *t)
 	/*
 	 * Collect CPU usage spent before yielding
 	 */
-	(void) CPUCAPS_CHARGE(t, &fssproc->fss_caps, CPUCAPS_CHARGE_ONLY);
+	(void) CPUCAPS_CHARGE(t, &fssproc->fss_caps, CPUCAPS_CHARGE_ENFORCE);
 
 	/*
 	 * Clear the preemption control "yield" bit since the user is
diff --git a/usr/src/uts/common/disp/fx.c b/usr/src/uts/common/disp/fx.c
index 53bfb46e2a..b4899e0edf 100644
--- a/usr/src/uts/common/disp/fx.c
+++ b/usr/src/uts/common/disp/fx.c
@@ -543,6 +543,13 @@ fx_exit(kthread_t *t)
 	thread_lock(t);
 	fxpp = (fxproc_t *)(t->t_cldata);
 
+	/*
+	 * A thread could be exiting in between clock ticks, so we need to
+	 * calculate how much CPU time it used since it was charged last time.
+	 *
+	 * CPU caps are not enforced on exiting processes - it is usually
+	 * desirable to exit as soon as possible to free resources.
+	 */
 	(void) CPUCAPS_CHARGE(t, &fxpp->fx_caps, CPUCAPS_CHARGE_ONLY);
 
 	if (FX_HAS_CB(fxpp)) {
@@ -1115,7 +1122,7 @@ fx_preempt(kthread_t *t)
 	ASSERT(t == curthread);
 	ASSERT(THREAD_LOCK_HELD(curthread));
 
-	(void) CPUCAPS_CHARGE(t, &fxpp->fx_caps, CPUCAPS_CHARGE_ONLY);
+	(void) CPUCAPS_CHARGE(t, &fxpp->fx_caps, CPUCAPS_CHARGE_ENFORCE);
 
 	/*
 	 * Check to see if we're doing "preemption control" here.  If
@@ -1209,7 +1216,7 @@ fx_sleep(kthread_t *t)
 	/*
 	 * Account for time spent on CPU before going to sleep.
 	 */
-	(void) CPUCAPS_CHARGE(t, &fxpp->fx_caps, CPUCAPS_CHARGE_ONLY);
+	(void) CPUCAPS_CHARGE(t, &fxpp->fx_caps, CPUCAPS_CHARGE_ENFORCE);
 
 	if (FX_HAS_CB(fxpp)) {
 		FX_CB_SLEEP(FX_CALLB(fxpp), fxpp->fx_cookie);
@@ -1428,7 +1435,7 @@ fx_yield(kthread_t *t)
 	/*
 	 * Collect CPU usage spent before yielding CPU.
 	 */
-	(void) CPUCAPS_CHARGE(t, &fxpp->fx_caps, CPUCAPS_CHARGE_ONLY);
+	(void) CPUCAPS_CHARGE(t, &fxpp->fx_caps, CPUCAPS_CHARGE_ENFORCE);
 
 	if (FX_HAS_CB(fxpp))  {
 		clock_t new_quantum =  (clock_t)fxpp->fx_pquantum;
diff --git a/usr/src/uts/common/disp/ts.c b/usr/src/uts/common/disp/ts.c
index a55b890e83..e071a80ab5 100644
--- a/usr/src/uts/common/disp/ts.c
+++ b/usr/src/uts/common/disp/ts.c
@@ -1320,6 +1320,10 @@ ts_exit(kthread_t *t)
 		 * A thread could be exiting in between clock ticks,
 		 * so we need to calculate how much CPU time it used
 		 * since it was charged last time.
+		 *
+		 * CPU caps are not enforced on exiting processes - it is
+		 * usually desirable to exit as soon as possible to free
+		 * resources.
 		 */
 		thread_lock(t);
 		tspp = (tsproc_t *)t->t_cldata;
@@ -1382,7 +1386,8 @@ ts_preempt(kthread_t *t)
 	 * Do not enforce CPU caps on threads running at a kernel priority
 	 */
 	if (CPUCAPS_ON()) {
-		(void) cpucaps_charge(t, &tspp->ts_caps, CPUCAPS_CHARGE_ONLY);
+		(void) cpucaps_charge(t, &tspp->ts_caps,
+		    CPUCAPS_CHARGE_ENFORCE);
 		if (!(tspp->ts_flags & TSKPRI) && CPUCAPS_ENFORCE(t))
 			return;
 	}
@@ -1509,7 +1514,7 @@ ts_sleep(kthread_t *t)
 	/*
 	 * Account for time spent on CPU before going to sleep.
 	 */
-	(void) CPUCAPS_CHARGE(t, &tspp->ts_caps, CPUCAPS_CHARGE_ONLY);
+	(void) CPUCAPS_CHARGE(t, &tspp->ts_caps, CPUCAPS_CHARGE_ENFORCE);
 
 	flags = tspp->ts_flags;
 	if (t->t_kpri_req) {
@@ -2026,7 +2031,7 @@ ts_yield(kthread_t *t)
 	/*
 	 * Collect CPU usage spent before yielding
 	 */
-	(void) CPUCAPS_CHARGE(t, &tspp->ts_caps, CPUCAPS_CHARGE_ONLY);
+	(void) CPUCAPS_CHARGE(t, &tspp->ts_caps, CPUCAPS_CHARGE_ENFORCE);
 
 	/*
 	 * Clear the preemption control "yield" bit since the user is