Re: Large inlines in include/linux/skbuff.h

[Andi Kleen]

On Thu, Apr 22, 2004 at 11:15:47AM -0400, James Morris wrote:
> On Thu, 22 Apr 2004, Andi Kleen wrote:
> 
> > > How will these changes impact performance?  I asked this last time you 
> > > posted about inlines and didn't see any response.
> > 
> > I don't think it will be an issue. The optimization guidelines
> > of AMD and Intel recommend to move functions that generate 
> > more than 30-40 instructions out of line. 100 instructions 
> > is certainly enough to amortize the call overhead, and you 
> > safe some icache too so it may be even faster.
> 
> Of course, but it would be good to see some measurements.

It's useless in this case. networking is dominated by cache misses
and locks and a modern CPU can do hundreds of function calls in a 
single cache miss.

-Andi
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