Messages in this thread | | | Date | Sun, 12 Dec 2004 17:35:47 +0100 | From | Pavel Machek <> | Subject | Re: dynamic-hz |
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Hi!
> The below patch allows to set the HZ dynamically at boot time with > command line parameter. HZ=1000 HZ=100 HZ=333 any other value just works > (though certain value may cause more or less drift to the system time > advance/decrease). > > Is there any interest from the mainline developers to merge this into > 2.6? I'm getting requests for this feature being forward ported to > 2.6 (both for batch jobs and for the powersaved that can trim the hz > down to 80mhz). It should be up to the user to choose the HZ like it was > in 2.4-aa. > > This patch is quite intrusive since many HZ visible to userspace have to > be converted to USER_HZ, and most important because HZ isn't available > at compile time anymore and every variable in function of HZ must be > either changed to be in function of USER_HZ or it must be initialized at > runtime. The code has debugging code (optional at compile time) so that > I can guarantee that there cannot be any regression. > > Technically this makes a lot of sense to me (well, you can guess why I > implemented it in the first place), at least in archs where one cannot > reprogram the timer chip in a performant way (to stop timer ticks > completely until the next posted timer). This is in production for years > in SLES8 btw. > > http://www.kernel.org/pub/linux/kernel/people/andrea/kernels/v2.4/2.4.23aa3/9999_zzz-dynamic-hz-5.gz
It certainly helps with singing capacitors... What is overhead of this?
Pavel -- People were complaining that M$ turns users into beta-testers... ...jr ghea gurz vagb qrirybcref, naq gurl frrz gb yvxr vg gung jnl! - 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/
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