127 	struct dirty_throttle_control *gdtc;	/* only set in memcg dtc's */
164 static bool mdtc_valid(struct dirty_throttle_control *dtc)  in mdtc_valid()  argument
166 	return dtc->dom;  in mdtc_valid()
169 static struct wb_domain *dtc_dom(struct dirty_throttle_control *dtc)  in dtc_dom()  argument
171 	return dtc->dom;  in dtc_dom()
218 static bool mdtc_valid(struct dirty_throttle_control *dtc)  in mdtc_valid()  argument
223 static struct wb_domain *dtc_dom(struct dirty_throttle_control *dtc)  in dtc_dom()  argument
380  * @dtc: dirty_throttle_control of interest
382  * Calculate @dtc->thresh and ->bg_thresh considering
384  * must ensure that @dtc->avail is set before calling this function.  The
387 static void domain_dirty_limits(struct dirty_throttle_control *dtc)  in domain_dirty_limits()  argument
389 	const unsigned long available_memory = dtc->avail;  in domain_dirty_limits()
390 	struct dirty_throttle_control *gdtc = mdtc_gdtc(dtc);  in domain_dirty_limits()
400 	/* gdtc is !NULL iff @dtc is for memcg domain */  in domain_dirty_limits()
444 	dtc->thresh = thresh;  in domain_dirty_limits()
445 	dtc->bg_thresh = bg_thresh;  in domain_dirty_limits()
756  * @dtc: dirty_throttle_context of interest
775 static unsigned long __wb_calc_thresh(struct dirty_throttle_control *dtc)  in __wb_calc_thresh()  argument
777 	struct wb_domain *dom = dtc_dom(dtc);  in __wb_calc_thresh()
778 	unsigned long thresh = dtc->thresh;  in __wb_calc_thresh()
786 	fprop_fraction_percpu(&dom->completions, dtc->wb_completions,  in __wb_calc_thresh()
793 	wb_min_max_ratio(dtc->wb, &wb_min_ratio, &wb_max_ratio);  in __wb_calc_thresh()
915 static void wb_position_ratio(struct dirty_throttle_control *dtc)  in wb_position_ratio()  argument
917 	struct bdi_writeback *wb = dtc->wb;  in wb_position_ratio()
919 	unsigned long freerun = dirty_freerun_ceiling(dtc->thresh, dtc->bg_thresh);  in wb_position_ratio()
920 	unsigned long limit = hard_dirty_limit(dtc_dom(dtc), dtc->thresh);  in wb_position_ratio()
921 	unsigned long wb_thresh = dtc->wb_thresh;  in wb_position_ratio()
929 	dtc->pos_ratio = 0;  in wb_position_ratio()
931 	if (unlikely(dtc->dirty >= limit))  in wb_position_ratio()
940 	pos_ratio = pos_ratio_polynom(setpoint, dtc->dirty, limit);  in wb_position_ratio()
970 		if (dtc->wb_dirty < 8) {  in wb_position_ratio()
971 			dtc->pos_ratio = min_t(long long, pos_ratio * 2,  in wb_position_ratio()
976 		if (dtc->wb_dirty >= wb_thresh)  in wb_position_ratio()
980 						    dtc->wb_bg_thresh);  in wb_position_ratio()
985 		wb_pos_ratio = pos_ratio_polynom(wb_setpoint, dtc->wb_dirty,  in wb_position_ratio()
1009 		dtc->pos_ratio = min(pos_ratio, wb_pos_ratio);  in wb_position_ratio()
1044 	if (unlikely(wb_thresh > dtc->thresh))  in wb_position_ratio()
1045 		wb_thresh = dtc->thresh;  in wb_position_ratio()
1053 	wb_thresh = max(wb_thresh, (limit - dtc->dirty) / 8);  in wb_position_ratio()
1058 	x = div_u64((u64)wb_thresh << 16, dtc->thresh | 1);  in wb_position_ratio()
1068 	span = (dtc->thresh - wb_thresh + 8 * write_bw) * (u64)x >> 16;  in wb_position_ratio()
1071 	if (dtc->wb_dirty < x_intercept - span / 4) {  in wb_position_ratio()
1072 		pos_ratio = div64_u64(pos_ratio * (x_intercept - dtc->wb_dirty),  in wb_position_ratio()
1083 	if (dtc->wb_dirty < x_intercept) {  in wb_position_ratio()
1084 		if (dtc->wb_dirty > x_intercept / 8)  in wb_position_ratio()
1086 					    dtc->wb_dirty);  in wb_position_ratio()
1091 	dtc->pos_ratio = pos_ratio;  in wb_position_ratio()
1144 static void update_dirty_limit(struct dirty_throttle_control *dtc)  in update_dirty_limit()  argument
1146 	struct wb_domain *dom = dtc_dom(dtc);  in update_dirty_limit()
1147 	unsigned long thresh = dtc->thresh;  in update_dirty_limit()
1163 	thresh = max(thresh, dtc->dirty);  in update_dirty_limit()
1173 static void domain_update_bandwidth(struct dirty_throttle_control *dtc,  in domain_update_bandwidth()  argument
1176 	struct wb_domain *dom = dtc_dom(dtc);  in domain_update_bandwidth()
1186 		update_dirty_limit(dtc);  in domain_update_bandwidth()
1198 static void wb_update_dirty_ratelimit(struct dirty_throttle_control *dtc,  in wb_update_dirty_ratelimit()  argument
1202 	struct bdi_writeback *wb = dtc->wb;  in wb_update_dirty_ratelimit()
1203 	unsigned long dirty = dtc->dirty;  in wb_update_dirty_ratelimit()
1204 	unsigned long freerun = dirty_freerun_ceiling(dtc->thresh, dtc->bg_thresh);  in wb_update_dirty_ratelimit()
1205 	unsigned long limit = hard_dirty_limit(dtc_dom(dtc), dtc->thresh);  in wb_update_dirty_ratelimit()
1226 					dtc->pos_ratio >> RATELIMIT_CALC_SHIFT;  in wb_update_dirty_ratelimit()
1315 		dirty = dtc->wb_dirty;  in wb_update_dirty_ratelimit()
1316 		if (dtc->wb_dirty < 8)  in wb_update_dirty_ratelimit()
1317 			setpoint = dtc->wb_dirty + 1;  in wb_update_dirty_ratelimit()
1319 			setpoint = (dtc->wb_thresh + dtc->wb_bg_thresh) / 2;  in wb_update_dirty_ratelimit()
1524 static inline void wb_dirty_limits(struct dirty_throttle_control *dtc)  in wb_dirty_limits()  argument
1526 	struct bdi_writeback *wb = dtc->wb;  in wb_dirty_limits()
1542 	dtc->wb_thresh = __wb_calc_thresh(dtc);  in wb_dirty_limits()
1543 	dtc->wb_bg_thresh = dtc->thresh ?  in wb_dirty_limits()
1544 		div64_u64(dtc->wb_thresh * dtc->bg_thresh, dtc->thresh) : 0;  in wb_dirty_limits()
1556 	if (dtc->wb_thresh < 2 * wb_stat_error()) {  in wb_dirty_limits()
1558 		dtc->wb_dirty = wb_reclaimable + wb_stat_sum(wb, WB_WRITEBACK);  in wb_dirty_limits()
1561 		dtc->wb_dirty = wb_reclaimable + wb_stat(wb, WB_WRITEBACK);  in wb_dirty_limits()
1682 		 * global dtc by default.  in balance_dirty_pages()
1743 		/* throttle according to the chosen dtc */  in balance_dirty_pages()