Re: softirq parameters

From: Rusty Russell (rusty@rustcorp.com.au)
Date: Wed Aug 07 2002 - 00:24:23 EST


On Sun, 04 Aug 2002 22:37:46 -0700 (PDT)
"David S. Miller" <davem@redhat.com> wrote:

> From: george anzinger <george@mvista.com>
> Date: Sun, 04 Aug 2002 10:38:23 -0700
>
> Matthew Wilcox wrote:
> > what do you guys think about this patch? nobody's using the data argument
> > to the softirq routines, but most of the routines want to know which
> > CPU they're running on.
>
> I would vote no on this. While no one is currently using
> the data argument, it would be _hard_ to replace it if it
> were needed. The cpu, on the other hand, is available
> regardless of it being passed or not and thus does not
> _need_ to be passed.
>
> Furthermore, this is one of the most important hot paths in
> the entire kernel, any simplification and or improvement
> in code generated to implement these paths is desirable.
>
> I fully supporty Matthew's change.

Partially agree. Removing all args might be worthwhile. But all these
softirqs use the "cpu" arg to access per-cpu data, which should be
changed to use the per_cpu_data mechanism anyway, which removes the
point of the arg.

Things haven't been changed over because I haven't pushed the per-cpu
interface changes (required for some archs 8() to Linus yet. But you'll
want them so we can save space (you only need allocate per-cpu data for
cpus where cpu_possible(i) is true).

Clear?
Rusty.

-- 
   there are those who do and those who hang on and you don't see too
   many doers quoting their contemporaries.  -- Larry McVoy
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/



This archive was generated by hypermail 2b29 : Wed Aug 07 2002 - 22:00:34 EST