303  * sugov_iowait_reset() - Reset the IO boost status of a CPU.
304  * @sg_cpu: the sugov data for the CPU to boost
306  * @set_iowait_boost: true if an IO boost has been requested
308  * The IO wait boost of a task is disabled after a tick since the last update
309  * of a CPU. If a new IO wait boost is requested after more then a tick, then
310  * we enable the boost starting from IOWAIT_BOOST_MIN, which improves energy
318 	/* Reset boost only if a tick has elapsed since last request */  in sugov_iowait_reset()
329  * sugov_iowait_boost() - Updates the IO boost status of a CPU.
330  * @sg_cpu: the sugov data for the CPU to boost
339  * To keep doubling, an IO boost has to be requested at least once per tick,
347 	/* Reset boost if the CPU appears to have been idle enough */  in sugov_iowait_boost()
352 	/* Boost only tasks waking up after IO */  in sugov_iowait_boost()
356 	/* Ensure boost doubles only one time at each request */  in sugov_iowait_boost()
361 	/* Double the boost at each request */  in sugov_iowait_boost()
368 	/* First wakeup after IO: start with minimum boost */  in sugov_iowait_boost()
373  * sugov_iowait_apply() - Apply the IO boost to a CPU.
374  * @sg_cpu: the sugov data for the cpu to boost
376  * @util: the utilization to (eventually) boost
381  * The IO boost value is increased each time a task wakes up from IO, in
386  * its IO boost utilization reset.
388  * This mechanism is designed to boost high frequently IO waiting tasks, while
394 	unsigned long boost;  in sugov_iowait_apply()  local
396 	/* No boost currently required */  in sugov_iowait_apply()
400 	/* Reset boost if the CPU appears to have been idle enough */  in sugov_iowait_apply()
406 		 * No boost pending; reduce the boost value.  in sugov_iowait_apply()
421 	boost = (sg_cpu->iowait_boost * max) >> SCHED_CAPACITY_SHIFT;  in sugov_iowait_apply()
422 	return max(boost, util);  in sugov_iowait_apply()