Similar to wb_dirty_limits which calculates dirty and thresh of wb, wb_bg_dirty_limits calculates background dirty and background thresh of wb. With wb_bg_dirty_limits, we could remove repeated code in wb_over_bg_thresh. Signed-off-by: Kemeng Shi <shikemeng@xxxxxxxxxxxxxxx> Acked-by: Tejun Heo <tj@xxxxxxxxxx> --- mm/page-writeback.c | 35 +++++++++++++++++++---------------- 1 file changed, 19 insertions(+), 16 deletions(-) diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 692c0da04cbd..e1f73643aca1 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -2087,6 +2087,21 @@ void balance_dirty_pages_ratelimited(struct address_space *mapping) } EXPORT_SYMBOL(balance_dirty_pages_ratelimited); +/* + * Similar to wb_dirty_limits, wb_bg_dirty_limits also calculates dirty + * and thresh, but it's for background writeback. + */ +static void wb_bg_dirty_limits(struct dirty_throttle_control *dtc) +{ + struct bdi_writeback *wb = dtc->wb; + + dtc->wb_bg_thresh = __wb_calc_thresh(dtc, dtc->bg_thresh); + if (dtc->wb_bg_thresh < 2 * wb_stat_error()) + dtc->wb_dirty = wb_stat_sum(wb, WB_RECLAIMABLE); + else + dtc->wb_dirty = wb_stat(wb, WB_RECLAIMABLE); +} + /** * wb_over_bg_thresh - does @wb need to be written back? * @wb: bdi_writeback of interest @@ -2103,8 +2118,6 @@ bool wb_over_bg_thresh(struct bdi_writeback *wb) struct dirty_throttle_control * const gdtc = &gdtc_stor; struct dirty_throttle_control * const mdtc = mdtc_valid(&mdtc_stor) ? &mdtc_stor : NULL; - unsigned long reclaimable; - unsigned long thresh; /* * Similar to balance_dirty_pages() but ignores pages being written @@ -2117,13 +2130,8 @@ bool wb_over_bg_thresh(struct bdi_writeback *wb) if (gdtc->dirty > gdtc->bg_thresh) return true; - thresh = __wb_calc_thresh(gdtc, gdtc->bg_thresh); - if (thresh < 2 * wb_stat_error()) - reclaimable = wb_stat_sum(wb, WB_RECLAIMABLE); - else - reclaimable = wb_stat(wb, WB_RECLAIMABLE); - - if (reclaimable > thresh) + wb_bg_dirty_limits(gdtc); + if (gdtc->wb_dirty > gdtc->wb_bg_thresh) return true; if (mdtc) { @@ -2137,13 +2145,8 @@ bool wb_over_bg_thresh(struct bdi_writeback *wb) if (mdtc->dirty > mdtc->bg_thresh) return true; - thresh = __wb_calc_thresh(mdtc, mdtc->bg_thresh); - if (thresh < 2 * wb_stat_error()) - reclaimable = wb_stat_sum(wb, WB_RECLAIMABLE); - else - reclaimable = wb_stat(wb, WB_RECLAIMABLE); - - if (reclaimable > thresh) + wb_bg_dirty_limits(mdtc); + if (mdtc->wb_dirty > mdtc->wb_bg_thresh) return true; } -- 2.30.0