This is a really shallow reaction but I was amused by the XXX&#x27;s in the document.  I got into the kernel at Sun and I thought XXX started with Sun, then realized it started at BSD.  Who knew that it went back to Multics?  Does it go back to the first OS ever?<p>I&#x27;m pretty sure you can grep the sunos sources and you&#x27;ll find a bunch of LMXXX in the file system and a few in the VM system (LM being my initials).<p>I suspect everyone here knows but just in case, XXX in a comment in the kernel indicates something that you think needs to be fixed, it&#x27;s kind of a &quot;we haven&#x27;t hit this issue yet but we will&quot;.