diff --git a/flow/Knobs.cpp b/flow/Knobs.cpp
index 98278d0bba..e6749f60d8 100644
--- a/flow/Knobs.cpp
+++ b/flow/Knobs.cpp
@@ -171,6 +171,7 @@ void FlowKnobs::initialize(Randomize randomize, IsSimulated isSimulated) {
 	init( MIN_LOGGED_PRIORITY_BUSY_FRACTION,                  0.05 );
 	init( CERT_FILE_MAX_SIZE,                      5 * 1024 * 1024 );
 	init( READY_QUEUE_RESERVED_SIZE,                          8192 );
+	init( ITERATIONS_PER_REACTOR_CHECK,                          5 );
 
 	//Network
 	init( PACKET_LIMIT,                                  100LL<<20 );
diff --git a/flow/Knobs.h b/flow/Knobs.h
index 0c84b0576b..f22ec4f0f1 100644
--- a/flow/Knobs.h
+++ b/flow/Knobs.h
@@ -226,6 +226,7 @@ public:
 	double MIN_LOGGED_PRIORITY_BUSY_FRACTION;
 	int CERT_FILE_MAX_SIZE;
 	int READY_QUEUE_RESERVED_SIZE;
+	int ITERATIONS_PER_REACTOR_CHECK;
 
 	// Network
 	int64_t PACKET_LIMIT;
diff --git a/flow/Net2.actor.cpp b/flow/Net2.actor.cpp
index c902a0027d..2a26ce8b84 100644
--- a/flow/Net2.actor.cpp
+++ b/flow/Net2.actor.cpp
@@ -1533,8 +1533,8 @@ void Net2::run() {
 				minTaskID = currentTaskID;
 			}
 
-			// attempt to empty out the IO backlog for every 5 tasks while in this loop
-			if (ready.size() % 5 == 1) {
+			// attempt to empty out the IO backlog
+			if (ready.size() % FLOW_KNOBS->ITERATIONS_PER_REACTOR_CHECK == 1) {
 				if (runFunc) {
 					runFunc();
 				}