25  * The window size (vmpressure_win) is the number of scanned pages before
26  * we try to analyze scanned/reclaimed ratio. So the window is used as a
42  * scanned/reclaimed ratio. The current values were chosen empirically. In
120 static enum vmpressure_levels vmpressure_calc_level(unsigned long scanned,  in vmpressure_calc_level()  argument
123 	unsigned long scale = scanned + reclaimed;  in vmpressure_calc_level()
127 	 * reclaimed can be greater than scanned for things such as reclaimed  in vmpressure_calc_level()
129 	 * related increment to scanned pages.  in vmpressure_calc_level()
131 	if (reclaimed >= scanned)  in vmpressure_calc_level()
135 	 * scanned vs. reclaimed in a given time frame (window). Note that  in vmpressure_calc_level()
137 	 * scanned. This makes it possible to set desired reaction time  in vmpressure_calc_level()
140 	pressure = scale - (reclaimed * scale / scanned);  in vmpressure_calc_level()
145 		 scanned, reclaimed);  in vmpressure_calc_level()
183 	unsigned long scanned;  in vmpressure_work_fn()  local
194 	 * just after the old work returns, but then scanned might be zero  in vmpressure_work_fn()
198 	scanned = vmpr->tree_scanned;  in vmpressure_work_fn()
199 	if (!scanned) {  in vmpressure_work_fn()
209 	level = vmpressure_calc_level(scanned, reclaimed);  in vmpressure_work_fn()
219  * vmpressure() - Account memory pressure through scanned/reclaimed ratio
223  * @scanned:	number of pages scanned
227  * "instantaneous" memory pressure (scanned/reclaimed ratio). The raw
240 		unsigned long scanned, unsigned long reclaimed)  in vmpressure()  argument
272 	 * If we got here with no pages scanned, then that is an indicator  in vmpressure()
279 	if (!scanned)  in vmpressure()
284 		scanned = vmpr->tree_scanned += scanned;  in vmpressure()
288 		if (scanned < vmpressure_win)  in vmpressure()
299 		scanned = vmpr->scanned += scanned;  in vmpressure()
301 		if (scanned < vmpressure_win) {  in vmpressure()
305 		vmpr->scanned = vmpr->reclaimed = 0;  in vmpressure()
308 		level = vmpressure_calc_level(scanned, reclaimed);  in vmpressure()
347 	 * range vmscan. Passing scanned = vmpressure_win, reclaimed = 0  in vmpressure_prio()