commit 9807db8cd3edcbec95862a10b27eda88b329424c
Author: James Wahlin <james.wahlin@10gen.com>
Date:   Fri Oct 16 11:08:54 2015 -0400

    Increase yield frequency and slow down query execution

diff --git a/src/mongo/db/query/query_knobs.cpp b/src/mongo/db/query/query_knobs.cpp
index e9095a7..0b6d13a 100644
--- a/src/mongo/db/query/query_knobs.cpp
+++ b/src/mongo/db/query/query_knobs.cpp
@@ -67,7 +67,7 @@ MONGO_EXPORT_SERVER_PARAMETER(internalQueryMaxScansToExplode, int, 200);
 MONGO_EXPORT_SERVER_PARAMETER(internalQueryExecMaxBlockingSortBytes, int, 32 * 1024 * 1024);
 
 // Yield every 128 cycles or 10ms.
-MONGO_EXPORT_SERVER_PARAMETER(internalQueryExecYieldIterations, int, 128);
+MONGO_EXPORT_SERVER_PARAMETER(internalQueryExecYieldIterations, int, 1);
 MONGO_EXPORT_SERVER_PARAMETER(internalQueryExecYieldPeriodMS, int, 10);
 
 }  // namespace mongo
diff --git a/src/mongo/db/query/query_yield.cpp b/src/mongo/db/query/query_yield.cpp
index 10d66de..1041dab 100644
--- a/src/mongo/db/query/query_yield.cpp
+++ b/src/mongo/db/query/query_yield.cpp
@@ -67,6 +67,8 @@ void QueryYield::yieldAllLocks(OperationContext* txn, RecordFetcher* fetcher) {
         fetcher->fetch();
     }
 
+    sleepmillis(100);
+
     locker->restoreLockState(snapshot);
 }