Re: [PATCH 05/10] vmscan: Synchrounous lumpy reclaim use lock_page() instead trylock_page()

[Johannes Weiner <hannes@cmpxchg.org>]

On Mon, Sep 06, 2010 at 11:47:28AM +0100, Mel Gorman wrote:
> From: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
> 
> With synchrounous lumpy reclaim, there is no reason to give up to reclaim
> pages even if page is locked. This patch uses lock_page() instead of
> trylock_page() in this case.
> 
> Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
> Signed-off-by: Mel Gorman <mel@csn.ul.ie>

Acked-by: Johannes Weiner <hannes@cmpxchg.org>

> ---
>  mm/vmscan.c |    4 +++-
>  1 files changed, 3 insertions(+), 1 deletions(-)
> 
> diff --git a/mm/vmscan.c b/mm/vmscan.c
> index 5979850..79bd812 100644
> --- a/mm/vmscan.c
> +++ b/mm/vmscan.c
> @@ -665,7 +665,9 @@ static unsigned long shrink_page_list(struct list_head *page_list,
>  		page = lru_to_page(page_list);
>  		list_del(&page->lru);
>  
> -		if (!trylock_page(page))
> +		if (sync_writeback == PAGEOUT_IO_SYNC)
> +			lock_page(page);
> +		else if (!trylock_page(page))
>  			goto keep;
>  
>  		VM_BUG_ON(PageActive(page));