diff options
| author | Tejun Heo <tj@kernel.org> | 2015-05-22 18:23:25 -0400 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2015-06-02 08:38:13 -0600 |
| commit | b1cbc6d40c85639d405fee37c7bb688c3bf468d6 (patch) | |
| tree | 3fade9185da49c4ba9d54fd77f5501d514b8b447 /mm/page-writeback.c | |
| parent | 970fb01ad3a773b5612a9bba6b366abcefc18eaf (diff) | |
writeback: make __wb_calc_thresh() take dirty_throttle_control
wb_calc_thresh() calculates wb_thresh by scaling thresh according to
the wb's portion in the system-wide write bandwidth. cgroup writeback
support would need to calculate wb_thresh against memcg domain too.
This patch renames wb_calc_thresh() to __wb_calc_thresh() and makes it
take dirty_throttle_control so that the function can later be updated
to calculate against different domains according to
dirty_throttle_control.
wb_calc_thresh() is now a thin wrapper around __wb_calc_thresh().
v2: The original version was incorrectly scaling dtc->dirty instead of
dtc->thresh. This was due to the extremely confusing function and
variable names. Added a rename patch and fixed this one.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Greg Thelen <gthelen@google.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'mm/page-writeback.c')
| -rw-r--r-- | mm/page-writeback.c | 21 |
1 files changed, 14 insertions, 7 deletions
diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 3ec922309178..2352c69bff12 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -557,9 +557,8 @@ static unsigned long hard_dirty_limit(unsigned long thresh) } /** - * wb_calc_thresh - @wb's share of dirty throttling threshold - * @wb: bdi_writeback to query - * @dirty: global dirty limit in pages + * __wb_calc_thresh - @wb's share of dirty throttling threshold + * @dtc: dirty_throttle_context of interest * * Returns @wb's dirty limit in pages. The term "dirty" in the context of * dirty balancing includes all PG_dirty, PG_writeback and NFS unstable pages. @@ -578,9 +577,10 @@ 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_calc_thresh(struct bdi_writeback *wb, unsigned long thresh) +static unsigned long __wb_calc_thresh(struct dirty_throttle_control *dtc) { struct wb_domain *dom = &global_wb_domain; + unsigned long thresh = dtc->thresh; u64 wb_thresh; long numerator, denominator; unsigned long wb_min_ratio, wb_max_ratio; @@ -588,14 +588,14 @@ unsigned long wb_calc_thresh(struct bdi_writeback *wb, unsigned long thresh) /* * Calculate this BDI's share of the thresh ratio. */ - fprop_fraction_percpu(&dom->completions, &wb->completions, + fprop_fraction_percpu(&dom->completions, &dtc->wb->completions, &numerator, &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_min_max_ratio(dtc->wb, &wb_min_ratio, &wb_max_ratio); wb_thresh += (thresh * wb_min_ratio) / 100; if (wb_thresh > (thresh * wb_max_ratio) / 100) @@ -604,6 +604,13 @@ unsigned long wb_calc_thresh(struct bdi_writeback *wb, unsigned long thresh) return wb_thresh; } +unsigned long wb_calc_thresh(struct bdi_writeback *wb, unsigned long thresh) +{ + struct dirty_throttle_control gdtc = { GDTC_INIT(wb), + .thresh = thresh }; + return __wb_calc_thresh(&gdtc); +} + /* * setpoint - dirty 3 * f(dirty) := 1.0 + (----------------) @@ -1323,7 +1330,7 @@ static inline void wb_dirty_limits(struct dirty_throttle_control *dtc) * wb_position_ratio() will let the dirtier task progress * at some rate <= (write_bw / 2) for bringing down wb_dirty. */ - dtc->wb_thresh = wb_calc_thresh(dtc->wb, dtc->thresh); + dtc->wb_thresh = __wb_calc_thresh(dtc); dtc->wb_bg_thresh = dtc->thresh ? div_u64((u64)dtc->wb_thresh * dtc->bg_thresh, dtc->thresh) : 0; |