Messages in this thread | | | Date | Tue, 23 Mar 2004 10:04:22 +1100 | From | Peter Williams <> | Subject | Re: finding out the value of HZ from userspace |
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Micha Feigin wrote: > On Sat, Mar 20, 2004 at 12:28:00PM +0100, Stefan Smietanowski wrote: > >>>>>there is one. Nothing uses it >>>>>(sysconf() provides this info) >>>> >>>>Seems to me that it would be fairly trivial to modify those programs >>>>(that should use this mechanism but don't) to use it? So why should >>>>they be allowed to dictate kernel behaviour? >>> >>> >>>quality of implementation; for example shell scripts that want to do >>>echo 500 > /proc/sys/foo/bar/something_in_HZ >>>... >>>or /etc/sysctl.conf or ... >>> >> >>Then write a simple program already. How hard is it to write a program >>that does a sysconf() and returns (as ascii of course) just the >>value of HZ? Then do some trivial calculation off of that. >> >>HZ=$(gethz) >> >>If your 500 was 5 seconds, do >> >>TIME=$[HZ*5] >>echo $TIME > /proc/sys/foo/bar/something_in_HZ >> > > > Will this be USER_HZ or kernel HZ? > Someone earlier suggested it would be USER_HZ which would make it > pointless.
It has to be whatever enables user space to correctly interpret values sent to user space as "ticks". That means USER_HZ and it's not useless as it enables USER_HZ to be different and/or change without breaking programs that use values expressed in "ticks".
> > >>I mean, come on. >> >>Then you include it in the default distro of choice so that >>everybody can use it and there you are. >> >>If someone doesn't have "gethz" then they can download it. >> >>// Stefan >> > > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/
-- Dr Peter Williams, Chief Scientist peterw@aurema.com Aurema Pty Limited Tel:+61 2 9698 2322 PO Box 305, Strawberry Hills NSW 2012, Australia Fax:+61 2 9699 9174 79 Myrtle Street, Chippendale NSW 2008, Australia http://www.aurema.com
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