lkml.org 
[lkml]   [2008]   [Mar]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH 1/5] split clocksource adjustment from clockosurce mult
From
Date

On Sat, 2008-03-15 at 05:28 +0100, Roman Zippel wrote:
> Hi,
>
> On Fri, 14 Mar 2008, john stultz wrote:
>
> > @@ -179,7 +181,7 @@ static inline cycle_t clocksource_read(struct clocksource *cs)
> > static inline s64 cyc2ns(struct clocksource *cs, cycle_t cycles)
> > {
> > u64 ret = (u64)cycles;
> > - ret = (ret * cs->mult) >> cs->shift;
> > + ret = (ret * (cs->mult + cs->mult_adj)) >> cs->shift;
> > return ret;
> > }
>
> This add an extra memory access and extra instruction to a code path, we
> should keep as short as possible.
> I'd rather add a mult_raw or mult_org and use that for your next patch.

Yea, I played with that at first, but the functoinal duplication (two
values, both storing close to the same info) was ugly.

I guess I could go back to mult_orig.

-john




\
 
 \ /
  Last update: 2008-03-15 06:09    [from the cache]
©2003-2011 Jasper Spaans