1 files changed, 31 insertions, 0 deletions
diff --git a/qa/tasks/cephfs/test_readahead.py b/qa/tasks/cephfs/test_readahead.py
new file mode 100644
index 00000000..31e7bf18
--- /dev/null
+++ b/qa/tasks/cephfs/test_readahead.py
@@ -0,0 +1,31 @@
+import logging
+from tasks.cephfs.fuse_mount import FuseMount
+from tasks.cephfs.cephfs_test_case import CephFSTestCase
+
+log = logging.getLogger(__name__)
+
+
+class TestReadahead(CephFSTestCase):
+    def test_flush(self):
+        if not isinstance(self.mount_a, FuseMount):
+            self.skipTest("FUSE needed for measuring op counts")
+
+        # Create 32MB file
+        self.mount_a.run_shell(["dd", "if=/dev/urandom", "of=foo", "bs=1M", "count=32"])
+
+        # Unmount and remount the client to flush cache
+        self.mount_a.umount_wait()
+        self.mount_a.mount()
+        self.mount_a.wait_until_mounted()
+
+        initial_op_r = self.mount_a.admin_socket(['perf', 'dump', 'objecter'])['objecter']['op_r']
+        self.mount_a.run_shell(["dd", "if=foo", "of=/dev/null", "bs=128k", "count=32"])
+        op_r = self.mount_a.admin_socket(['perf', 'dump', 'objecter'])['objecter']['op_r']
+        assert op_r >= initial_op_r
+        op_r -= initial_op_r
+        log.info("read operations: {0}".format(op_r))
+
+        # with exponentially increasing readahead, we should see fewer than 10 operations
+        # but this test simply checks if the client is doing a remote read for each local read
+        if op_r >= 32:
+            raise RuntimeError("readahead not working")