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Re: [PATCH 1/7] posix-timers: tidy up clock interfaces and consolidate dispatch logic
George Anzinger <george@xxxxxxxxxx> wrote:
> > /*
> > + * Define this to initialize every k_clock function table so all its
> > + * function pointers are non-null, and always do indirect calls through the
> > + * table. Leave it undefined to instead leave null function pointers and
> > + * decide at the call sites between a direct call (maybe inlined) to the
> > + * default function and an indirect call through the table when it's filled
> > + * in. Which style is preferable is whichever performs better in the
> > + * common case of using the default functions.
> > +#define CLOCK_DISPATCH_DIRECT
> As I understand it modern machines, the indirect call does really bad things to
> the pipeline. The default call, even preceeded by the if, will be much faster
> by this reasoning. I would, therefor, prefer not defining CLOCK_DISPATCH_DIRECT.
We do need to do one or the other. I assume the current indecision is
pending some benchmarking work?
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