Re: [MM] Make mm counters per cpu instead of atomic V2

[KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>]

On Thu, 5 Nov 2009 10:36:06 -0500 (EST)
Christoph Lameter <cl@linux-foundation.org> wrote:

> +static inline unsigned long get_mm_rss(struct mm_struct *mm)
> +{
> +	int cpu;
> +	unsigned long r = 0;
> +
> +	for_each_possible_cpu(cpu) {
> +		struct mm_counter *c = per_cpu_ptr(mm->rss, cpu);
> +
> +		r = c->file + c->anon;
> +	}
> +
> +	return r;
> +}
> +
> +static inline void update_hiwater_rss(struct mm_struct *mm)
> +{
> +	unsigned long _rss = get_mm_rss(mm);
> +	if (mm->hiwater_rss < _rss)
> +		mm->hiwater_rss = _rss;
> +}
> +

I'm sorry for my replies are scatterd.

Isn't it better to add some filter in following path ?

==
static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
                                enum ttu_flags flags)
{
<snip>
       /* Update high watermark before we lower rss */
        update_hiwater_rss(mm);
==

Thanks,
-Kame

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