Messages in this thread | | | Date | Thu, 7 May 2009 10:19:25 -0700 | From | Tim Bird <> | Subject | Re: How to use a different sched_clock() for ftrace on omap? |
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Kevin Hilman wrote: > Tim Bird <tim.bird@am.sony.com> writes: > >> Hi all, >> >> I've worked up a replacement sched_clock for ftrace on my omap platform. >> The current sched_clock, based on the 32K timer, has low resolution and >> doesn't provide very useful results. >> >> Unfortunately, I'm not sure the best way to use my special one, in place >> of a common one in arch/arm/plat-omap/common.c > > Hi Tim, > > If you're comiling mach-omap1/time.c than you've enabled the > higher-resolution MPU timer with CONFIG_OMAP_MPU_TIMER, right?
Yes.
> In that case, you could make the one in plat-omap/common.c inside and > #ifndef CONFIG_OMAP_MPU_TIMER and put the new one in the MPU_TIMER > code. > > To be complete, you should add the same to the mach-omap2/timer-gp.c > as well.
I was trying to avoid using #ifdefs, but maybe in this case it makes sense. There are tradeoffs in using the different timers (nicely described in plat-omap/Kconfig help entries), so IMHO it would be good to make this a config preference.
I'll work up a patch in this style and send it along. -- Tim
============================= Tim Bird Architecture Group Chair, CE Linux Forum Senior Staff Engineer, Sony Corporation of America =============================
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