On Wed 20-09-17 09:05:51, Jens Axboe wrote: > On 09/20/2017 08:41 AM, Jan Kara wrote: > > 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 <[email protected]> > > > > ... > > > >> +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. > > I don't mind making that change, but I think that should be a separate > patch. We're using get_nr_dirty_pages() in existing locations where > we have the 'wb', like in wb_check_old_data_flush().
Good point and fully agreed. So you can add: Reviewed-by: Jan Kara <[email protected]> for this patch. Honza -- Jan Kara <[email protected]> SUSE Labs, CR
