Re: [PATCH 7/8] mm: vmscan: Immediately reclaim end-of-LRU dirty pages when writeback completes

[Peter Zijlstra <peterz@xxxxxxxxxxxxx>]

On Thu, 2011-07-21 at 17:28 +0100, Mel Gorman wrote:
> When direct reclaim encounters a dirty page, it gets recycled around
> the LRU for another cycle. This patch marks the page PageReclaim
> similar to deactivate_page() so that the page gets reclaimed almost
> immediately after the page gets cleaned. This is to avoid reclaiming
> clean pages that are younger than a dirty page encountered at the
> end of the LRU that might have been something like a use-once page.
> 

> @@ -834,7 +834,15 @@ static unsigned long shrink_page_list(struct list_head 
> *page_list,
>                        */
>                       if (page_is_file_cache(page) &&
>                                       (!current_is_kswapd() || priority >= 
> DEF_PRIORITY - 2)) {
> -                             inc_zone_page_state(page, NR_VMSCAN_WRITE_SKIP);
> +                             /*
> +                              * Immediately reclaim when written back.
> +                              * Similar in principal to deactivate_page()
> +                              * except we already have the page isolated
> +                              * and know it's dirty
> +                              */
> +                             inc_zone_page_state(page, NR_VMSCAN_INVALIDATE);
> +                             SetPageReclaim(page);
> +

I find the invalidate name somewhat confusing. It makes me think we'll
drop the page without writeback, like invalidatepage().