From 0d960a383ae7aa791b2833e122ba7519d264cf92 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Fri, 22 May 2015 18:23:19 -0400 Subject: writeback: clean up wb_dirty_limit() The function name wb_dirty_limit(), its argument @dirty and the local variable @wb_dirty are mortally confusing given that the function calculates per-wb threshold value not dirty pages, especially given that @dirty and @wb_dirty are used elsewhere for dirty pages. Let's rename the function to wb_calc_thresh() and wb_dirty to wb_thresh. Signed-off-by: Tejun Heo Cc: Jens Axboe Cc: Jan Kara Cc: Wu Fengguang Cc: Greg Thelen Signed-off-by: Jens Axboe --- mm/page-writeback.c | 30 +++++++++++++++--------------- 1 file changed, 15 insertions(+), 15 deletions(-) (limited to 'mm/page-writeback.c') diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 70cf98dc3423..c7745a7fe11e 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -556,7 +556,7 @@ static unsigned long hard_dirty_limit(unsigned long thresh) } /** - * wb_dirty_limit - @wb's share of dirty throttling threshold + * wb_calc_thresh - @wb's share of dirty throttling threshold * @wb: bdi_writeback to query * @dirty: global dirty limit in pages * @@ -577,28 +577,28 @@ static unsigned long hard_dirty_limit(unsigned long thresh) * The wb's share of dirty limit will be adapting to its throughput and * bounded by the bdi->min_ratio and/or bdi->max_ratio parameters, if set. */ -unsigned long wb_dirty_limit(struct bdi_writeback *wb, unsigned long dirty) +unsigned long wb_calc_thresh(struct bdi_writeback *wb, unsigned long thresh) { - u64 wb_dirty; + u64 wb_thresh; long numerator, denominator; unsigned long wb_min_ratio, wb_max_ratio; /* - * Calculate this BDI's share of the dirty ratio. + * Calculate this BDI's share of the thresh ratio. */ wb_writeout_fraction(wb, &numerator, &denominator); - wb_dirty = (dirty * (100 - bdi_min_ratio)) / 100; - wb_dirty *= numerator; - do_div(wb_dirty, denominator); + wb_thresh = (thresh * (100 - bdi_min_ratio)) / 100; + wb_thresh *= numerator; + do_div(wb_thresh, denominator); wb_min_max_ratio(wb, &wb_min_ratio, &wb_max_ratio); - wb_dirty += (dirty * wb_min_ratio) / 100; - if (wb_dirty > (dirty * wb_max_ratio) / 100) - wb_dirty = dirty * wb_max_ratio / 100; + wb_thresh += (thresh * wb_min_ratio) / 100; + if (wb_thresh > (thresh * wb_max_ratio) / 100) + wb_thresh = thresh * wb_max_ratio / 100; - return wb_dirty; + return wb_thresh; } /* @@ -750,7 +750,7 @@ static unsigned long wb_position_ratio(struct bdi_writeback *wb, * total amount of RAM is 16GB, bdi->max_ratio is equal to 1%, global * limits are set by default to 10% and 20% (background and throttle). * Then wb_thresh is 1% of 20% of 16GB. This amounts to ~8K pages. - * wb_dirty_limit(wb, bg_thresh) is about ~4K pages. wb_setpoint is + * wb_calc_thresh(wb, bg_thresh) is about ~4K pages. wb_setpoint is * about ~6K pages (as the average of background and throttle wb * limits). The 3rd order polynomial will provide positive feedback if * wb_dirty is under wb_setpoint and vice versa. @@ -1115,7 +1115,7 @@ static void wb_update_dirty_ratelimit(struct bdi_writeback *wb, * * We rampup dirty_ratelimit forcibly if wb_dirty is low because * it's possible that wb_thresh is close to zero due to inactivity - * of backing device (see the implementation of wb_dirty_limit()). + * of backing device (see the implementation of wb_calc_thresh()). */ if (unlikely(wb->bdi->capabilities & BDI_CAP_STRICTLIMIT)) { dirty = wb_dirty; @@ -1123,7 +1123,7 @@ static void wb_update_dirty_ratelimit(struct bdi_writeback *wb, setpoint = wb_dirty + 1; else setpoint = (wb_thresh + - wb_dirty_limit(wb, bg_thresh)) / 2; + wb_calc_thresh(wb, bg_thresh)) / 2; } if (dirty < setpoint) { @@ -1352,7 +1352,7 @@ static inline void wb_dirty_limits(struct bdi_writeback *wb, * wb_position_ratio() will let the dirtier task progress * at some rate <= (write_bw / 2) for bringing down wb_dirty. */ - *wb_thresh = wb_dirty_limit(wb, dirty_thresh); + *wb_thresh = wb_calc_thresh(wb, dirty_thresh); if (wb_bg_thresh) *wb_bg_thresh = dirty_thresh ? div_u64((u64)*wb_thresh * -- cgit v1.2.3-55-g7522