Messages in this thread | | | Date | Fri, 12 Jul 2002 14:01:06 +0200 | From | Martin Dalecki <> | Subject | Re: HZ, preferably as small as possible |
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Użytkownik Bill Davidsen napisał: > On Thu, 11 Jul 2002, Martin Dalecki wrote: > > >>vmstat.c: >> >>hz = sysconf(_SC_CLK_TCK); /* get ticks/s from system */ >> >>And yes I know the libproc is *evil* in this area. >>The rest should be an implementation detail of sysconf(). > > > Yes, any of the changes need to make the dynamic value available to > programs. Alas, too many programs grab the HZ value and compile it in, and > don't work right on a kernel with a modified rate. I don't know if the > CLK_TCK macro is dynamic or not, I sure hope so. > > I'd like to see it set at boot time, and available in /proc/sys for easy > use by scripts. As noted by others, there are a lot of uses in the kernel > source which assume that arithmetic will happen at compile time, and even > if you ignore the overhead it would take a lot of rewriting to make it > dynamic. Setting it a boot time gets most of the gain and none of the > pain (boot time = pick a kernel, not a parameter). >
IMHO there where reasons why the standards are defining a function to access this information from applications.
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