From e9770b3487328b7e28803caf6c809292dd7adbf0 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Fri, 22 May 2015 18:23:27 -0400 Subject: [PATCH] writeback: add dirty_throttle_control->wb_completions wb->completions measures the wb's proportional write bandwidth in global_wb_domain and thus naturally tied to the wb_domain. This patch adds dirty_throttle_control->wb_completions which is initialized to wb->completions by GDTC_INIT() and updates __wb_dirty_limits() to use it instead of dereferencing wb->completions directly. This will allow dirty_throttle_control to represent different wb_domains and the matching wb completions. This patch doesn't introduce any behavioral changes. 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 | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/mm/page-writeback.c b/mm/page-writeback.c index fcebae7db874..5b439fc1e95e 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -127,6 +127,7 @@ struct wb_domain global_wb_domain; /* consolidated parameters for balance_dirty_pages() and its subroutines */ struct dirty_throttle_control { struct bdi_writeback *wb; + struct fprop_local_percpu *wb_completions; unsigned long dirty; /* file_dirty + write + nfs */ unsigned long thresh; /* dirty threshold */ @@ -139,7 +140,8 @@ struct dirty_throttle_control { unsigned long pos_ratio; }; -#define GDTC_INIT(__wb) .wb = (__wb) +#define GDTC_INIT(__wb) .wb = (__wb), \ + .wb_completions = &(__wb)->completions /* * Length of period for aging writeout fractions of bdis. This is an @@ -590,7 +592,7 @@ static unsigned long __wb_calc_thresh(struct dirty_throttle_control *dtc) /* * Calculate this BDI's share of the thresh ratio. */ - fprop_fraction_percpu(&dom->completions, &dtc->wb->completions, + fprop_fraction_percpu(&dom->completions, dtc->wb_completions, &numerator, &denominator); wb_thresh = (thresh * (100 - bdi_min_ratio)) / 100; -- 2.39.5