On Wed 20-09-17 09:33:01, Jens Axboe wrote:
> Now that we have no external callers of wb_start_writeback(), we
> can shuffle the passing in of 'nr_pages'. Everybody passes in 0
> at this point, so just kill the argument and move the dirty
> count retrieval to that function.
>
> Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx>
> Tested-by: Chris Mason <clm@xxxxxx>
> Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Looks good. You can add:
Reviewed-by: Jan Kara <jack@xxxxxxx>
Honza
> ---
> fs/fs-writeback.c | 42 ++++++++++++++++++------------------------
> 1 file changed, 18 insertions(+), 24 deletions(-)
>
> diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
> index ecbd26d1121d..3916ea2484ae 100644
> --- a/fs/fs-writeback.c
> +++ b/fs/fs-writeback.c
> @@ -933,8 +933,19 @@ static void bdi_split_work_to_wbs(struct backing_dev_info *bdi,
>
> #endif /* CONFIG_CGROUP_WRITEBACK */
>
> -static void wb_start_writeback(struct bdi_writeback *wb, long nr_pages,
> - bool range_cyclic, enum wb_reason reason)
> +/*
> + * Add in the number of potentially dirty inodes, because each inode
> + * write can dirty pagecache in the underlying blockdev.
> + */
> +static unsigned long get_nr_dirty_pages(void)
> +{
> + return global_node_page_state(NR_FILE_DIRTY) +
> + global_node_page_state(NR_UNSTABLE_NFS) +
> + get_nr_dirty_inodes();
> +}
> +
> +static void wb_start_writeback(struct bdi_writeback *wb, bool range_cyclic,
> + enum wb_reason reason)
> {
> struct wb_writeback_work *work;
>
> @@ -954,7 +965,7 @@ static void wb_start_writeback(struct bdi_writeback *wb, long nr_pages,
> }
>
> work->sync_mode = WB_SYNC_NONE;
> - work->nr_pages = nr_pages;
> + work->nr_pages = wb_split_bdi_pages(wb, get_nr_dirty_pages());
> work->range_cyclic = range_cyclic;
> work->reason = reason;
> work->auto_free = 1;
> @@ -1814,17 +1825,6 @@ static struct wb_writeback_work *get_next_work_item(struct bdi_writeback *wb)
> return work;
> }
>
> -/*
> - * Add in the number of potentially dirty inodes, because each inode
> - * write can dirty pagecache in the underlying blockdev.
> - */
> -static unsigned long get_nr_dirty_pages(void)
> -{
> - return global_node_page_state(NR_FILE_DIRTY) +
> - global_node_page_state(NR_UNSTABLE_NFS) +
> - get_nr_dirty_inodes();
> -}
> -
> static long wb_check_background_flush(struct bdi_writeback *wb)
> {
> if (wb_over_bg_thresh(wb)) {
> @@ -1951,7 +1951,7 @@ void wb_workfn(struct work_struct *work)
> * write back the whole world.
> */
> static void __wakeup_flusher_threads_bdi(struct backing_dev_info *bdi,
> - long nr_pages, enum wb_reason reason)
> + enum wb_reason reason)
> {
> struct bdi_writeback *wb;
>
> @@ -1959,17 +1959,14 @@ static void __wakeup_flusher_threads_bdi(struct backing_dev_info *bdi,
> return;
>
> list_for_each_entry_rcu(wb, &bdi->wb_list, bdi_node)
> - wb_start_writeback(wb, wb_split_bdi_pages(wb, nr_pages),
> - false, reason);
> + wb_start_writeback(wb, false, reason);
> }
>
> void wakeup_flusher_threads_bdi(struct backing_dev_info *bdi,
> enum wb_reason reason)
> {
> - long nr_pages = get_nr_dirty_pages();
> -
> rcu_read_lock();
> - __wakeup_flusher_threads_bdi(bdi, nr_pages, reason);
> + __wakeup_flusher_threads_bdi(bdi, reason);
> rcu_read_unlock();
> }
>
> @@ -1979,7 +1976,6 @@ void wakeup_flusher_threads_bdi(struct backing_dev_info *bdi,
> void wakeup_flusher_threads(enum wb_reason reason)
> {
> struct backing_dev_info *bdi;
> - long nr_pages;
>
> /*
> * If we are expecting writeback progress we must submit plugged IO.
> @@ -1987,11 +1983,9 @@ void wakeup_flusher_threads(enum wb_reason reason)
> if (blk_needs_flush_plug(current))
> blk_schedule_flush_plug(current);
>
> - nr_pages = get_nr_dirty_pages();
> -
> rcu_read_lock();
> list_for_each_entry_rcu(bdi, &bdi_list, bdi_list)
> - __wakeup_flusher_threads_bdi(bdi, nr_pages, reason);
> + __wakeup_flusher_threads_bdi(bdi, reason);
> rcu_read_unlock();
> }
>
> --
> 2.7.4
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
