134 	unsigned long		thresh;		/* dirty threshold */  member
379  * domain_dirty_limits - calculate thresh and bg_thresh for a wb_domain
382  * Calculate @dtc->thresh and ->bg_thresh considering
396 	unsigned long thresh;  in domain_dirty_limits()  local
421 		thresh = DIV_ROUND_UP(bytes, PAGE_SIZE);  in domain_dirty_limits()
423 		thresh = (ratio * available_memory) / PAGE_SIZE;  in domain_dirty_limits()
433 		thresh += thresh / 4 + global_wb_domain.dirty_limit / 32;  in domain_dirty_limits()
439 	if (thresh > UINT_MAX)  in domain_dirty_limits()
440 		thresh = UINT_MAX;  in domain_dirty_limits()
442 	if (bg_thresh >= thresh)  in domain_dirty_limits()
443 		bg_thresh = thresh / 2;  in domain_dirty_limits()
444 	dtc->thresh = thresh;  in domain_dirty_limits()
449 		trace_global_dirty_state(bg_thresh, thresh);  in domain_dirty_limits()
455  * @pdirty: out parameter for thresh
457  * Calculate bg_thresh and thresh for global_wb_domain.  See
468 	*pdirty = gdtc.thresh;  in global_dirty_limits()
727 static unsigned long dirty_freerun_ceiling(unsigned long thresh,  in dirty_freerun_ceiling()  argument
730 	return (thresh + bg_thresh) / 2;  in dirty_freerun_ceiling()
734 				      unsigned long thresh)  in hard_dirty_limit()  argument
736 	return max(thresh, dom->dirty_limit);  in hard_dirty_limit()
778 	unsigned long thresh = dtc->thresh;  in __wb_calc_thresh()  local
784 	 * Calculate this BDI's share of the thresh ratio.  in __wb_calc_thresh()
789 	wb_thresh = (thresh * (100 - bdi_min_ratio)) / 100;  in __wb_calc_thresh()
795 	wb_thresh += (thresh * wb_min_ratio) / 100;  in __wb_calc_thresh()
796 	if (wb_thresh > (thresh * wb_max_ratio) / 100)  in __wb_calc_thresh()
797 		wb_thresh = thresh * wb_max_ratio / 100;  in __wb_calc_thresh()
802 unsigned long wb_calc_thresh(struct bdi_writeback *wb, unsigned long thresh)  in wb_calc_thresh()  argument
805 					       .thresh = thresh };  in wb_calc_thresh()
913  * - the wb dirty thresh drops quickly due to change of JBOD workload
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()
1044 	if (unlikely(wb_thresh > dtc->thresh))  in wb_position_ratio()
1045 		wb_thresh = dtc->thresh;  in wb_position_ratio()
1056 	 *	wb_setpoint = setpoint * wb_thresh / thresh  in wb_position_ratio()
1058 	x = div_u64((u64)wb_thresh << 16, dtc->thresh | 1);  in wb_position_ratio()
1062 	 * (thresh - wb_thresh ~= 0) and transit to wb_thresh in JBOD case.  in wb_position_ratio()
1064 	 *        wb_thresh                    thresh - wb_thresh  in wb_position_ratio()
1066 	 *         thresh                           thresh  in wb_position_ratio()
1068 	span = (dtc->thresh - wb_thresh + 8 * write_bw) * (u64)x >> 16;  in wb_position_ratio()
1147 	unsigned long thresh = dtc->thresh;  in update_dirty_limit()  local
1153 	if (limit < thresh) {  in update_dirty_limit()
1154 		limit = thresh;  in update_dirty_limit()
1159 	 * Follow down slowly. Use the higher one as the target, because thresh  in update_dirty_limit()
1163 	thresh = max(thresh, dtc->dirty);  in update_dirty_limit()
1164 	if (limit > thresh) {  in update_dirty_limit()
1165 		limit -= (limit - thresh) >> 5;  in update_dirty_limit()
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()
1422 					 unsigned long thresh)  in dirty_poll_interval()  argument
1424 	if (thresh > dirty)  in dirty_poll_interval()
1425 		return 1UL << (ilog2(thresh - dirty) >> 1);  in dirty_poll_interval()
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()
1551 	 * Otherwise it would be possible to get thresh+n pages  in wb_dirty_limits()
1552 	 * reported dirty, even though there are thresh-m pages  in wb_dirty_limits()
1596 		unsigned long dirty, thresh, bg_thresh;  in balance_dirty_pages()  local
1611 			thresh = gdtc->wb_thresh;  in balance_dirty_pages()
1615 			thresh = gdtc->thresh;  in balance_dirty_pages()
1640 				m_thresh = mdtc->thresh;  in balance_dirty_pages()
1657 		if (dirty <= dirty_freerun_ceiling(thresh, bg_thresh) &&  in balance_dirty_pages()
1664 			intv = dirty_poll_interval(dirty, thresh);  in balance_dirty_pages()
1699 			((gdtc->dirty > gdtc->thresh) || strictlimit);  in balance_dirty_pages()
1726 				((mdtc->dirty > mdtc->thresh) || strictlimit);  in balance_dirty_pages()
1770 						  sdtc->thresh,  in balance_dirty_pages()
1799 					  sdtc->thresh,  in balance_dirty_pages()
1819 		 * This is typically equal to (dirty < thresh) and can also  in balance_dirty_pages()