On Tue 19-09-17 13:53:06, Jens Axboe wrote:
> Now that we have no external callers of wb_start_writeback(),
> we can move the nr_pages == 0 logic into that function.
>
> Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
...
> +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, long nr_pages,
> bool range_cyclic, enum wb_reason reason)
> {
> @@ -942,6 +953,12 @@ static void wb_start_writeback(struct bdi_writeback *wb, long nr_pages,
> return;
>
> /*
> + * If someone asked for zero pages, we write out the WORLD
> + */
> + if (!nr_pages)
> + nr_pages = get_nr_dirty_pages();
> +
So for 'wb' we have a better estimate of the amount we should write - use
wb_stat_sum(wb, WB_RECLAIMABLE) statistics - that is essentially dirty +
unstable_nfs broken down to bdi_writeback.
Honza
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
