On 09/20/2017 09:36 AM, Jan Kara wrote: > 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]>
Thanks Jan, added. I just sent out the new version, mainly because the removal or 'nr_pages' changes the later patches a bit. All for the better, in my opinion. -- Jens Axboe
