Re: [PATCH] In-kernel module loader 3/7

Roman Zippel (zippel@linux-m68k.org)
Thu, 19 Sep 2002 01:07:16 +0200 (CEST)


Hi,

On Wed, 18 Sep 2002, Rusty Russell wrote:

> +/* Stopping interrupts faster than atomics on many archs (and more
> + easily optimized if they're not) */
> +static inline void bigref_inc(struct bigref *ref)
> +{
> + unsigned long flags;
> + struct bigref_percpu *cpu;
> +
> + local_irq_save(flags);
> + cpu = &ref->ref[smp_processor_id()];
> + if (likely(!cpu->slow_mode))
> + cpu->counter++;

Did you benchmark this? On most UP machines an inc/dec should be cheaper
than irq enable/disable.

bye, Roman

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