Hi, Amit Kulkarni wrote on Sun, Jan 06, 2019 at 12:16:30PM -0600:
> I wanted to know the value of tick, went to man.openbsd.org, > and got https://man.openbsd.org/tick > > While the answer provided on this page below is accurate, > IMHO it is not useful. I had to do a grep on "tick" for > the kern.clockrate sysctl. Something like the below would be better. No, it wouldn't, for two reasons. 1. hz(9) is a kernel manual page, so referencing the (low-level) system call manual (in section 2) which provides considerable detail that kernel hackers may need is better than referencing the (high-level) userland manual (in section 8) which doesn't even mention clockrate except below EXAMPLES. That example could easily go away one day without hz(9) noticing. 2. In general, sysctl(8) only documents how the sysctl(8) command line user interface works in general, but not the individual variables, not even for interactive or shell programming use. Individual variables are documented in sysctl(2) - both the numeric #defines and the textual names. Whether to reference "struct clockinfo", "KERN_CLOCKRATE", or "kern.clockrate" is a question of the colour of the bikeshed. Looking in sysctl(2) for any of the three, you immediately find the other two: KERN_CLOCKRATE (kern.clockrate) A struct clockinfo structure is returned. This structure And there aren't even false positives for any of the three in sysctl(2), so it is impossible to miss the right place. Besides, it kind of makes sense for the kernel manual to reference the struct rather than the textual name, because i guess the struct is what a kernel hacker will more often deal with than with the name. People who are not kernel hackers rarely need to worry about about ticks in the first place, but even they can readily find the information in sysctl(2) with the existing text. Yours, Ingo > diff --git man9/hz.9 man9/hz.9 > index a319266e518..ac5e8f60850 100644 > --- man9/hz.9 > +++ man9/hz.9 > @@ -79,11 +79,11 @@ may be used to skew this increment, but by no more > than ten times > .Va tickadj . > .Pp > -Those systems variables are available as a struct clockinfo from > -.Xr sysctl 2 . > +These system variables are available as kern.clockrate from > +.Xr sysctl 8 . > .Sh SEE ALSO > .Xr adjtime 2 , > .Xr clock_getres 2 , > -.Xr sysctl 2 , > +.Xr sysctl 8 , > .Xr hardclock 9 , > .Xr microtime 9 >
