[deadlock fix: reset the flag *after* checking the blackhole queue
Simon Marlow <marlowsd@gmail.com>**20081105150542] {
hunk ./rts/Schedule.c 865
-	    checkBlackHoles(cap);
hunk ./rts/Schedule.c 866
+            // important that we reset the flag *before* checking the
+            // blackhole queue, otherwise we could get deadlock.  This
+            // happens as follows: we wake up a thread that
+            // immediately runs on another Capability, blocks on a
+            // blackhole, and then we reset the blackholes_need_checking flag.
+	    checkBlackHoles(cap);
}