Re: [PATCH] writeback: remove unused parameter from balance_dirty_pages()

[Michal Hocko]

On Wed 27-09-17 15:13:11, Tahsin Erdogan wrote:
> "mapping" parameter to balance_dirty_pages() is not used anymore.
> 
> Fixes: dfb8ae567835 ("writeback: let balance_dirty_pages() work on the matching cgroup bdi_writeback")

balance_dirty_pages_ratelimited doesn't really need mapping as well. All
it needs is the inode and we already have it in callers. So would it
make sense to refactor a bit further and make its argument an inode?

> Signed-off-by: Tahsin Erdogan <tahsin@xxxxxxxxxx>

Acked-by: Michal Hocko <mhocko@xxxxxxxx>

> ---
>  mm/page-writeback.c | 5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
> 
> diff --git a/mm/page-writeback.c b/mm/page-writeback.c
> index 0b9c5cbe8eba..d89663f00e93 100644
> --- a/mm/page-writeback.c
> +++ b/mm/page-writeback.c
> @@ -1559,8 +1559,7 @@ static inline void wb_dirty_limits(struct dirty_throttle_control *dtc)
>   * If we're over `background_thresh' then the writeback threads are woken to
>   * perform some writeout.
>   */
> -static void balance_dirty_pages(struct address_space *mapping,
> -				struct bdi_writeback *wb,
> +static void balance_dirty_pages(struct bdi_writeback *wb,
>  				unsigned long pages_dirtied)
>  {
>  	struct dirty_throttle_control gdtc_stor = { GDTC_INIT(wb) };
> @@ -1910,7 +1909,7 @@ void balance_dirty_pages_ratelimited(struct address_space *mapping)
>  	preempt_enable();
>  
>  	if (unlikely(current->nr_dirtied >= ratelimit))
> -		balance_dirty_pages(mapping, wb, current->nr_dirtied);
> +		balance_dirty_pages(wb, current->nr_dirtied);
>  
>  	wb_put(wb);
>  }
> -- 
> 2.14.2.822.g60be5d43e6-goog
> 

-- 
Michal Hocko
SUSE Labs