examples: add a butterfly seek job file

Add a job file that approximates doing
read at start
read at end
read at start+1
read at end-1
[...]
read at end-1
read at start+1
read at end
read at start

Signed-off-by: Sitsofe Wheeler <sitsofe@yahoo.com>

diff --git a/doc/fio_examples.rst b/doc/fio_examples.rst
index ae0ef6f8b923de7fca5a22d29495f03f9629888c..cff1f39444b5f63f24294b97a9f13436572719a0 100644 (file)
--- a/doc/fio_examples.rst
+++ b/doc/fio_examples.rst
@@ -60,3 +60,13 @@ Fixed rate submission
 
 .. literalinclude:: ../examples/fixed-rate-submission.fio
        :language: ini
 
 .. literalinclude:: ../examples/fixed-rate-submission.fio
        :language: ini

+
+Butterfly seek pattern
+-----------------------
+
+.. only:: builder_html
+
+:download:`Download butterfly.fio <../examples/butterfly.fio>`
+
+.. literalinclude:: ../examples/butterfly.fio
+       :language: ini

diff --git a/examples/butterfly.fio b/examples/butterfly.fio
new file mode 100644 (file)
index 0000000..42d253d
--- /dev/null
+++ b/examples/butterfly.fio
@@ -0,0 +1,19 @@
+# Perform a butterfly/funnel seek pattern. This won't always alternate ends on
+# every I/O but it will get close.
+
+[global]
+filename=/tmp/testfile
+bs=4k
+direct=1
+
+[forward]
+rw=read
+flow=2
+# Uncomment the size= and offset= lines to prevent each direction going past
+# the middle of the file
+#size=50%
+
+[backward]
+rw=read:-8k
+flow=-2
+#offset=50%