> > On Sep 11, 2017, at 9:25 AM, Theo de Raadt <[email protected]> > wrote: > > > >> Scott Cheloha: > >> > >>> Use a monotonic clock for the elapsed time trial. > >> > >> FreeBSD uses getrusage() to fetch the user time used. I think that > > >> makes more sense. > >> > >> > https://svnweb.freebsd.org/base/head/sbin/md5/md5.c?revision=3D307658&view=markup#l293 > > > > The granularity is weak. However you can stop such a process, then > > let it continue, and get a reasonable assessment of the cputime it > > actually used. Which is perhaps closer to the stated goal. > > > > Compared to that, CLOCK_MONOTONIC vs CLOCK_REALTIME vs whatever else > > doesn't seem that valuable a change to me. I'll note none of these > > diffs come with a clear problem statement. > > My thinking with the use of CLOCK_MONOTONIC was that it made the measured > time immune to clock jumps and changes to the system time by root via > settimeofday(2). > > This gets us closer to what the time trial is trying to measure, even > if root does something like resetting the system clock in the midst of > the program's execution, which would make the output totally incorrect > if we were using gettimeofday(2).
Huh? Where do you get that? It seems obvious the intent is performance of algorithm, rather than "how busy is the machine". Read naddy's comment again.
