Hi Jeff, The difference is that recycle does not require you to keep around (or be given) the untyped in order to then be able to perform the retype. Recycle is also a single syscall, and thus has better performance, than revoke + retype. Adrian On Wed 26-Oct-2016 3:11 PM, Jeff Waugh wrote: On Wed, Oct 26, 2016 at 2:54 PM, <Adrian.Danis@data61.csiro.au<mailto:Adrian.Danis@data61.csiro.au>> wrote: Whilst we do not use recycle we would like to first find out if anybody in the community is using recycle, or has a strong argument for why they would like it to stay. If this is you, please let us know, otherwise we will continue with our plans for removal. A question rather than an argument: What is the cost difference between recycle vs. revoke + retype these days? (c.f. tables 7.1, 7.2, and 7.3, and section 7.1.5 in Elkaduwe 2010 [1]). Thanks, Jeff [1] https://ts.data61.csiro.au/publications/papers/Elkaduwe:phd.pdf