<html> <head> <meta http-equiv="content-type" content="text/html; charset=ISO-8859-1"> </head> <body bgcolor="#FFFFFF" text="#000000"> Good day to all. If I've some block device "base" and I've two derived device-mapper devices "derived1" and "derived2" that are copy-on-write layers over top of that base, and I mount the filesystems on those derived block devices and run the same program "foo" from both, does the "foo" running from "derived1" share any [read and execute] memory pages with the "foo" running from "derived2", since the underlying sectors are both from the same position on "base"? The more general question would be about mmap, but I hope this example is clear. "Docker"[1] uses device-mapper in scenarios like the above example and I'm curious if they benefit from shared pages. [1] <a class="moz-txt-link-freetext" href="https://www.docker.com/">https://www.docker.com/</a> <div class="moz-signature">-- <meta http-equiv="content-type" content="text/html; charset=ISO-8859-1"> Shao Miller Network Technician 905-836-4442 ext: 112 <a href="http://www.treefrog.ca/shao-miller" style="font-style: normal; font-weight: normal; font-size: 10px;">www.treefrog.ca/shao-miller</a> Treefrog Inc. <div> 905-836-4442 567 Davis Drive, Newmarket, ON <a href="http://www.treefrog.ca/">www.treefrog.ca</a> - @Treefrog </div> </div> </body> </html>