Re: likely and unlikely was: Re: [PATCH] split xfs_ioc_xattr

Eric Sandeen
2008-04-18T14:05:23Z

Timothy Shimmin wrote:
> Hi,
>
> Thanks for the explanation, Andi.
> So I guess the upshot is, that it can make a difference but
> in many cases (where the perf difference isn't an issue)
> it is probably not worth the ugliness.
> And in performance cases, it would be best to test the hypothesis
> with the unlikely profiler patch
> => it will be _unlikely_ we will bother ;-)
> So I don't think I'll be bothering with them then unless
> an issue comes up :)
>
> --Tim

ISTR that the dir2 code on Irix had tons of compiler pragmas for likely
and unlikely paths, and that it actually was well-profiled and tested.
Did that ever get translated into Linux hints?

-Eric