[PATCH] Add thinktime_blocks

Right now 'thinktime' waits after every IO. This may not be what you
need, sometimes you want to wait only after 'x' number of ios. This
options allows you to set the number of ios to complete, before waiting.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/fio.h b/fio.h
index 4bb1f6c..2f41eda 100644
--- a/fio.h
+++ b/fio.h
@@ -217,6 +217,7 @@
 	unsigned int hugepage_size;
 	unsigned int rw_min_bs;
 	unsigned int thinktime;
+	unsigned int thinktime_blocks;
 	unsigned int fsync_blocks;
 	unsigned int start_delay;
 	unsigned long timeout;