Messages in this thread | | | Date | Thu, 20 Nov 2008 17:46:04 +0000 | From | "Will Newton" <> | Subject | Re: [PATCH] init/main.c: Use ktime accessor function in initcall_debug code. |
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On Thu, Nov 20, 2008 at 5:39 PM, Tim Bird <tim.bird@am.sony.com> wrote: > Will Newton wrote: >> The initcall_debug code access the tv64 member of ktime. This won't work >> correctly for large deltas on platforms that don't use the scalar ktime >> implementation. > > In principle I see no problem with this. But as a matter of > practice it may be overkill.
Possibly, but it makes the code clearer I think.
> How big does the delta have to be for this to be a problem? > And how much overhead does ktime_to_ns() add?
Deltas over a second will be incorrect. I have serial8250_init taking 8 seconds at the moment, so that isn't unheard of.
On scalar ktime architectures it should be zero, on others a multiply and an add (it's an inline). I wouldn't call it a fast path though.
> -- Tim > > ============================= > Tim Bird > Architecture Group Chair, CE Linux Forum > Senior Staff Engineer, Sony Corporation of America > ============================= > >
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