3  *  Floating proportions with flexible aging period
14  * Where x_{i,j} is j's number of events in i-th last time period and x_i is
15  * total number of events in i-th last time period.
26  * When a new period is declared, we could do:
33  * occurs. This can bit trivially implemented by remembering last period in
42 	p->period = 0;  in fprop_global_init()
57  * Declare @periods new periods. It is upto the caller to make sure period
83 	p->period += periods;  in fprop_new_period()
97 	pl->period = 0;  in fprop_local_init_single()
109 	unsigned int period = p->period;  in fprop_reflect_period_single()  local
112 	/* Fast path - period didn't change */  in fprop_reflect_period_single()
113 	if (pl->period == period)  in fprop_reflect_period_single()
116 	/* Someone updated pl->period while we were spinning? */  in fprop_reflect_period_single()
117 	if (pl->period >= period) {  in fprop_reflect_period_single()
122 	if (period - pl->period < BITS_PER_LONG)  in fprop_reflect_period_single()
123 		pl->events >>= period - pl->period;  in fprop_reflect_period_single()
126 	pl->period = period;  in fprop_reflect_period_single()
179 	pl->period = 0;  in fprop_local_init_percpu()
192 	unsigned int period = p->period;  in fprop_reflect_period_percpu()  local
195 	/* Fast path - period didn't change */  in fprop_reflect_period_percpu()
196 	if (pl->period == period)  in fprop_reflect_period_percpu()
199 	/* Someone updated pl->period while we were spinning? */  in fprop_reflect_period_percpu()
200 	if (pl->period >= period) {  in fprop_reflect_period_percpu()
205 	if (period - pl->period < BITS_PER_LONG) {  in fprop_reflect_period_percpu()
212 			-val + (val >> (period-pl->period)), PROP_BATCH);  in fprop_reflect_period_percpu()
215 	pl->period = period;  in fprop_reflect_period_percpu()