On Sat, Aug 12, 2006 at 06:06:02PM +0200, Thomas Koeller wrote:
> > > + while (1) continue;
> >
> > cpu_relax();
>
> I tried to find out about the purpose of cpu_relax(). On MIPS, at least,
> it maps to barrier(). I do not quite understand why I would need a
> barrier() in this place. Would you, or someone else, care to
> enlighten me?
Busy wait loops are meant to be filled with cpu_relax() in Linux. On
processors like the Pentium 4 this expands into something that keeps
the CPU from consuming excessive amounts of energy for just twiddling
thumbs and probably also CPU dependant. On MIPS cpu_relax() so far is
meaningless and therfore just defined as barrier().
Ralf
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