Re: [PATCH 1/3] writeback: change nr_pages_dirtied argument into local variable

[Fengguang Wu <fengguang.wu@intel.com>]

On Sat, Aug 18, 2012 at 05:48:29AM -0400, Namjae Jeon wrote:
> There is no reason nr_pages_dirtied is argument anymore.
> because nr_pages_dirtied value from caller is not used in
> balance_dirty_pages_ratelimited_nr function.

Looks good to me. If the fs developers don't have problems with this,
I'll apply it to the writeback tree.

Thanks,
Fengguang

> Signed-off-by: Namjae Jeon <linkinjeon@gmail.com>
> Signed-off-by: Vivek Trivedi <vtrivedi018@gmail.com>
> ---
>  fs/btrfs/disk-io.c        |    8 ++++----
>  fs/btrfs/file.c           |    3 +--
>  fs/btrfs/ioctl.c          |    2 +-
>  fs/ocfs2/file.c           |    5 +----
>  fs/splice.c               |    5 +----
>  include/linux/writeback.h |    9 +--------
>  mm/page-writeback.c       |   11 +++++------
>  7 files changed, 14 insertions(+), 29 deletions(-)
> 
> diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
> index 62e0caf..10b6128 100644
> --- a/fs/btrfs/disk-io.c
> +++ b/fs/btrfs/disk-io.c
> @@ -3344,8 +3344,8 @@ void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
>  	num_dirty = root->fs_info->dirty_metadata_bytes;
>  
>  	if (num_dirty > thresh) {
> -		balance_dirty_pages_ratelimited_nr(
> -				   root->fs_info->btree_inode->i_mapping, 1);
> +		balance_dirty_pages_ratelimited(
> +				   root->fs_info->btree_inode->i_mapping);
>  	}
>  	return;
>  }
> @@ -3365,8 +3365,8 @@ void __btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
>  	num_dirty = root->fs_info->dirty_metadata_bytes;
>  
>  	if (num_dirty > thresh) {
> -		balance_dirty_pages_ratelimited_nr(
> -				   root->fs_info->btree_inode->i_mapping, 1);
> +		balance_dirty_pages_ratelimited(
> +				   root->fs_info->btree_inode->i_mapping);
>  	}
>  	return;
>  }
> diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
> index f6b40e8..0dae684 100644
> --- a/fs/btrfs/file.c
> +++ b/fs/btrfs/file.c
> @@ -1314,8 +1314,7 @@ static noinline ssize_t __btrfs_buffered_write(struct file *file,
>  
>  		cond_resched();
>  
> -		balance_dirty_pages_ratelimited_nr(inode->i_mapping,
> -						   dirty_pages);
> +		balance_dirty_pages_ratelimited(inode->i_mapping);
>  		if (dirty_pages < (root->leafsize >> PAGE_CACHE_SHIFT) + 1)
>  			btrfs_btree_balance_dirty(root, 1);
>  
> diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
> index 7bb7556..df2e9fb 100644
> --- a/fs/btrfs/ioctl.c
> +++ b/fs/btrfs/ioctl.c
> @@ -1199,7 +1199,7 @@ int btrfs_defrag_file(struct inode *inode, struct file *file,
>  		}
>  
>  		defrag_count += ret;
> -		balance_dirty_pages_ratelimited_nr(inode->i_mapping, ret);
> +		balance_dirty_pages_ratelimited(inode->i_mapping);
>  		mutex_unlock(&inode->i_mutex);
>  
>  		if (newer_than) {
> diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
> index 46a1f6d..a83c964 100644
> --- a/fs/ocfs2/file.c
> +++ b/fs/ocfs2/file.c
> @@ -2515,18 +2515,15 @@ static ssize_t ocfs2_file_splice_write(struct pipe_inode_info *pipe,
>  		ret = sd.num_spliced;
>  
>  	if (ret > 0) {
> -		unsigned long nr_pages;
>  		int err;
>  
> -		nr_pages = (ret + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
> -
>  		err = generic_write_sync(out, *ppos, ret);
>  		if (err)
>  			ret = err;
>  		else
>  			*ppos += ret;
>  
> -		balance_dirty_pages_ratelimited_nr(mapping, nr_pages);
> +		balance_dirty_pages_ratelimited(mapping);
>  	}
>  
>  	return ret;
> diff --git a/fs/splice.c b/fs/splice.c
> index 41514dd..36b6c17 100644
> --- a/fs/splice.c
> +++ b/fs/splice.c
> @@ -1024,17 +1024,14 @@ generic_file_splice_write(struct pipe_inode_info *pipe, struct file *out,
>  		ret = sd.num_spliced;
>  
>  	if (ret > 0) {
> -		unsigned long nr_pages;
>  		int err;
>  
> -		nr_pages = (ret + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
> -
>  		err = generic_write_sync(out, *ppos, ret);
>  		if (err)
>  			ret = err;
>  		else
>  			*ppos += ret;
> -		balance_dirty_pages_ratelimited_nr(mapping, nr_pages);
> +		balance_dirty_pages_ratelimited(mapping);
>  	}
>  	sb_end_write(inode->i_sb);
>  
> diff --git a/include/linux/writeback.h b/include/linux/writeback.h
> index 50c3e8f..b82a83a 100644
> --- a/include/linux/writeback.h
> +++ b/include/linux/writeback.h
> @@ -161,14 +161,7 @@ void __bdi_update_bandwidth(struct backing_dev_info *bdi,
>  			    unsigned long start_time);
>  
>  void page_writeback_init(void);
> -void balance_dirty_pages_ratelimited_nr(struct address_space *mapping,
> -					unsigned long nr_pages_dirtied);
> -
> -static inline void
> -balance_dirty_pages_ratelimited(struct address_space *mapping)
> -{
> -	balance_dirty_pages_ratelimited_nr(mapping, 1);
> -}
> +void balance_dirty_pages_ratelimited(struct address_space *mapping);
>  
>  typedef int (*writepage_t)(struct page *page, struct writeback_control *wbc,
>  				void *data);
> diff --git a/mm/page-writeback.c b/mm/page-writeback.c
> index 5ad5ce2..49133b6 100644
> --- a/mm/page-writeback.c
> +++ b/mm/page-writeback.c
> @@ -1069,7 +1069,7 @@ static void bdi_update_bandwidth(struct backing_dev_info *bdi,
>  }
>  
>  /*
> - * After a task dirtied this many pages, balance_dirty_pages_ratelimited_nr()
> + * After a task dirtied this many pages, balance_dirty_pages_ratelimited()
>   * will look to see if it needs to start dirty throttling.
>   *
>   * If dirty_poll_interval is too low, big NUMA machines will call the expensive
> @@ -1436,9 +1436,8 @@ static DEFINE_PER_CPU(int, bdp_ratelimits);
>  DEFINE_PER_CPU(int, dirty_throttle_leaks) = 0;
>  
>  /**
> - * balance_dirty_pages_ratelimited_nr - balance dirty memory state
> + * balance_dirty_pages_ratelimited - balance dirty memory state
>   * @mapping: address_space which was dirtied
> - * @nr_pages_dirtied: number of pages which the caller has just dirtied
>   *
>   * Processes which are dirtying memory should call in here once for each page
>   * which was newly dirtied.  The function will periodically check the system's
> @@ -1449,8 +1448,7 @@ DEFINE_PER_CPU(int, dirty_throttle_leaks) = 0;
>   * limit we decrease the ratelimiting by a lot, to prevent individual processes
>   * from overshooting the limit by (ratelimit_pages) each.
>   */
> -void balance_dirty_pages_ratelimited_nr(struct address_space *mapping,
> -					unsigned long nr_pages_dirtied)
> +void balance_dirty_pages_ratelimited(struct address_space *mapping)
>  {
>  	struct backing_dev_info *bdi = mapping->backing_dev_info;
>  	int ratelimit;
> @@ -1484,6 +1482,7 @@ void balance_dirty_pages_ratelimited_nr(struct address_space *mapping,
>  	 */
>  	p = &__get_cpu_var(dirty_throttle_leaks);
>  	if (*p > 0 && current->nr_dirtied < ratelimit) {
> +		unsigned long nr_pages_dirtied;
>  		nr_pages_dirtied = min(*p, ratelimit - current->nr_dirtied);
>  		*p -= nr_pages_dirtied;
>  		current->nr_dirtied += nr_pages_dirtied;
> @@ -1493,7 +1492,7 @@ void balance_dirty_pages_ratelimited_nr(struct address_space *mapping,
>  	if (unlikely(current->nr_dirtied >= ratelimit))
>  		balance_dirty_pages(mapping, current->nr_dirtied);
>  }
> -EXPORT_SYMBOL(balance_dirty_pages_ratelimited_nr);
> +EXPORT_SYMBOL(balance_dirty_pages_ratelimited);
>  
>  void throttle_vm_writeout(gfp_t gfp_mask)
>  {
> -- 
> 1.7.9.5