Messages in this thread | | | Date | Fri, 26 Mar 2004 14:03:01 -0500 | From | Jeff Garzik <> | Subject | Re: [PATCH] Consolidate multiple implementations of jiffies-msecs conversions. |
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Sridhar Samudrala wrote: > On Fri, 26 Mar 2004, Edgar Toernig wrote: > > >>Sridhar Samudrala wrote: >> >>>The following patch to 2.6.5-rc2 consolidates 6 different implementations >>>of msecs to jiffies and 3 different implementation of jiffies to msecs. >>>All of them now use the generic msecs_to_jiffies() and jiffies_to_msecs() >>>that are added to include/linux/time.h >>>[...] >>>-#define MSECS(ms) (((ms)*HZ/1000)+1) >>>-return (((ms)*HZ+999)/1000); >>>+return (msecs / 1000) * HZ + (msecs % 1000) * HZ / 1000; >> >>Did you check that all users of the new version will work correctly >>with your rounding? Explicit round-up of delays is often required, >>especially when talking to hardware... > > > I don't see any issues with the 2.6 default HZ value of 1000 as they become > no-ops and there is no need for any rounding. > I guess you are referring to cases when HZ < 1000(ex: 100) and msecs is > less than 10. In those cases, the new version returns 0, whereas some of the > older versions return 1.
We'll definitely want to return 1 rather than zero, for the uses in my drivers, at least...
Jeff
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