On Nov 28, 2017, at 6:13 PM, Ken Moffat <[email protected]> wrote: > > For a long time we have used SBUs as an indication of how long it > will take to build a package, and until recently my own figures, > when I compared them, seemed to match the book. > > But when I upgraded my installed firefoxes to 57.0 I was, for once, > ready ahead of time (before the official release date) and I updated > my "supported" older systems before doing the book. The SBUs were > all over the place - from memory, 60 or 70 SBU on a fast-ish machine > using 4 cores, but 100 SBU on my old i3. I put some of that down to > a lack of memory (only 4GB), but later tests showed it was only > barely using swap. > > Over the last 24 hours I've been updating qtwebengine and I see > similar variation in the number of SBUs. I wonder if it is worth > noting that the timings, particularly for large slow C++ programs, > can vary a lot between different machines ?
Here's an idea: A script, introduced early in the book, could record build times in a file using a format easily parsed. Upon completion of a BLFS system, the reader could send this file to the BLFS project along with dmesg output. Collect as many of these as you wish, run them through a program that parses and calculates the mean and standard deviation of the build times, and you'll have a very good way to estimate best/worst/average case build times. -- http://lists.linuxfromscratch.org/listinfo/blfs-support FAQ: http://www.linuxfromscratch.org/blfs/faq.html Unsubscribe: See the above information page
