On Thu Dec 19 05:02:50 EST 2013, 9f...@hamnavoe.com wrote: > > So, I think you are saying, that for pieces in a mkfile that take less than > > 1s to build it is possible for them to be build again, unnecessarily, when > > mk is run again. This is normal and just the way it is. Is that correct? > > Correct except for "just the way it is". There is a principle > involved which is so pervasive to Plan 9 that we often forget to make > it explicit. To quote Ken Thompson: "Throughout, simplicity has been > substituted for efficiency. Complex algorithms are used only if their > complexity can be localized." He was writing in 1978 about UNIX, but > Plan 9 follows firmly in this tradition. (Linux not so much.) > > Using the existing file time stamps costs some efficiency, when > targets are built more often than necessary. The question is, how > significant is this cost compared to the complexity of adding higher > time resolution? Note that it's not necessary to run mk repeatedly > until it converges -- the algorithm is conservative in the sense that > it will not build less than required. > > So, how many seconds is the unnecessary building of targets actually > costing?
+1. i just love to hear this approach expressed better than i can. sorry for my redundant post. - erik
