Re: [PATCH 4/5] mm: Only IPI CPUs to drain local pages if they exist

[Peter Zijlstra <a.p.zijlstra@chello.nl>]

On Sun, 2011-09-25 at 11:54 +0300, Gilad Ben-Yossef wrote:
> +static inline void inc_pcp_count(int cpu, struct per_cpu_pages *pcp, int count)
> +{
> +       if (unlikely(!total_cpu_pcp_count))

	if (unlikely(!__this_cpu_read(total_cpu_pco_count))

> +               cpumask_set_cpu(cpu, cpus_with_pcp);
> +
> +       total_cpu_pcp_count += count;

	__this_cpu_add(total_cpu_pcp_count, count);

> +       pcp->count += count;
> +}
> +
> +static inline void dec_pcp_count(int cpu, struct per_cpu_pages *pcp, int count)
> +{
> +       pcp->count -= count;
> +       total_cpu_pcp_count -= count;

	__this_cpu_sub(total_cpu_pcp_count, count);

> +
> +       if (unlikely(!total_cpu_pcp_count))

	if (unlikely(!__this_cpu_read(total_cpu_pcp_count))

> +               cpumask_clear_cpu(cpu, cpus_with_pcp);
> +}