[PATCH v5 9/9] memcg: check memcg dirty limits in page writeback

[Vivek Goyal]

On Fri, Feb 25, 2011 at 01:36:00PM -0800, Greg Thelen wrote:

[..]
> @@ -500,18 +527,27 @@ static void balance_dirty_pages(struct address_space *mapping,
>  		};
>  
>  		global_dirty_info(&sys_info);
> +		if (!memcg_dirty_info(NULL, &memcg_info))
> +			memcg_info = sys_info;
>  
>  		/*
>  		 * Throttle it only when the background writeback cannot
>  		 * catch-up. This avoids (excessively) small writeouts
>  		 * when the bdi limits are ramping up.
>  		 */
> -		if (dirty_info_reclaimable(&sys_info) + sys_info.nr_writeback <=
> +		if ((dirty_info_reclaimable(&sys_info) +
> +		     sys_info.nr_writeback <=
>  				(sys_info.background_thresh +
> -				 sys_info.dirty_thresh) / 2)
> +				 sys_info.dirty_thresh) / 2) &&
> +		    (dirty_info_reclaimable(&memcg_info) +
> +		     memcg_info.nr_writeback <=
> +				(memcg_info.background_thresh +
> +				 memcg_info.dirty_thresh) / 2))
>  			break;
>  
> -		bdi_thresh = bdi_dirty_limit(bdi, sys_info.dirty_thresh);
> +		bdi_thresh = bdi_dirty_limit(bdi,
> +				min(sys_info.dirty_thresh,
> +				    memcg_info.dirty_thresh));
>  		bdi_thresh = task_dirty_limit(current, bdi_thresh);

Greg, so currently we seem to have per_bdi/per_task dirty limits and
now with this patch it will sort of become per_cgroup/per_bdi/per_task
dirty limits? I think that kind of makes sense to me.

Thanks
Vivek