Update README.md

Author: bitfaster

README.md

@@ -1,2 +1,11 @@
 # cache-datasets
-Data sets for testing cache algorithms
+Data sets for testing cache algorithms.
+
+## Arc
+
+Data mirrored from [Dharmendra S. Modha's IBM page](https://researcher.watson.ibm.com/researcher/view_person_subpage.php?id=4700). The original links to dropbox can't be downloaded without dropbox authentication.
+
+Nimrod Megiddo and Dharmendra S. Modha, "ARC: A Self-Tuning, Low Overhead Replacement Cache," USENIX Conference on File and Storage Technologies (FAST 03), San Francisco, CA, pp. 115-130, March 31-April 2, 2003.
+
+- Arc.OLTP.zip
+