[Devel] Re: [PATCH 8/8] Per-container pages reclamation

[Balbir Singh]

Pavel Emelianov wrote:
> Implement try_to_free_pages_in_container() to free the
> pages in container that has run out of memory.
> 
> The scan_control->isolate_pages() function isolates the
> container pages only.
> 

Pavel,

I've just started playing around with these patches, I preferred
the approach of v1. Please see below

> +static unsigned long isolate_container_pages(unsigned long nr_to_scan,
> +		struct list_head *src, struct list_head *dst,
> +		unsigned long *scanned, struct zone *zone)
> +{
> +	unsigned long nr_taken = 0;
> +	struct page *page;
> +	struct page_container *pc;
> +	unsigned long scan;
> +	LIST_HEAD(pc_list);
> +
> +	for (scan = 0; scan < nr_to_scan && !list_empty(src); scan++) {
> +		pc = list_entry(src->prev, struct page_container, list);
> +		page = pc->page;
> +		if (page_zone(page) != zone)
> +			continue;

shrink_zone() will walk all pages looking for pages belonging to this
container and this slows down the reclaim quite a bit. Although we've
reused code, we've ended up walking the entire list of the zone to
find pages belonging to a particular container, this was the same
problem I had with my RSS controller patches.

> +
> +		list_move(&pc->list, &pc_list);
> +


-- 
	Warm Regards,
	Balbir Singh
	Linux Technology Center
	IBM, ISTL