Re: [PATCH] local_t : Documentation

From: Pavel Machek
Date: Tue Jan 09 2007 - 17:41:40 EST


Hi!

> > > These patches extend and standardise local_t operations on each architectures,
> > > allowing a rich set of atomic operations to be done on per-cpu data with
> > > minimal performance impact. On some architectures, there seems to be no
> > > difference between the SMP and UP operation (same memory barriers, same
> > > LOCking), local.h simply includes asm-generic/local.h, which removes duplicated
> > > code.
> >
> > Could you provide some Documentation/? Knowing when local_t can be
> > used is kind-of important.
>
> Hi Pavel,
>
> Thanks for this appropriate comment. I totally agree that there is a need for
> documentation about how local_t variables should be used. Here is the patch
> that adds Documentation/local_ops.txt. Comments are welcome.

AFAICT this fails to mention... Is local_t as big as int? As big as
long? Or perhaps smaller because high bits may be needed for locking?

Pavel

--
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