176  * sugov_iowait_reset() - Reset the IO boost status of a CPU.
177  * @sg_cpu: the sugov data for the CPU to boost
179  * @set_iowait_boost: true if an IO boost has been requested
181  * The IO wait boost of a task is disabled after a tick since the last update
182  * of a CPU. If a new IO wait boost is requested after more then a tick, then
183  * we enable the boost starting from IOWAIT_BOOST_MIN, which improves energy
191 	/* Reset boost only if a tick has elapsed since last request */  in sugov_iowait_reset()
202  * sugov_iowait_boost() - Updates the IO boost status of a CPU.
203  * @sg_cpu: the sugov data for the CPU to boost
212  * To keep doubling, an IO boost has to be requested at least once per tick,
220 	/* Reset boost if the CPU appears to have been idle enough */  in sugov_iowait_boost()
225 	/* Boost only tasks waking up after IO */  in sugov_iowait_boost()
229 	/* Ensure boost doubles only one time at each request */  in sugov_iowait_boost()
234 	/* Double the boost at each request */  in sugov_iowait_boost()
241 	/* First wakeup after IO: start with minimum boost */  in sugov_iowait_boost()
246  * sugov_iowait_apply() - Apply the IO boost to a CPU.
247  * @sg_cpu: the sugov data for the cpu to boost
252  * The IO boost value is increased each time a task wakes up from IO, in
257  * its IO boost utilization reset.
259  * This mechanism is designed to boost high frequently IO waiting tasks, while
264 	unsigned long boost;  in sugov_iowait_apply()  local
266 	/* No boost currently required */  in sugov_iowait_apply()
270 	/* Reset boost if the CPU appears to have been idle enough */  in sugov_iowait_apply()
276 		 * No boost pending; reduce the boost value.  in sugov_iowait_apply()
291 	boost = (sg_cpu->iowait_boost * sg_cpu->max) >> SCHED_CAPACITY_SHIFT;  in sugov_iowait_apply()
292 	if (sg_cpu->util < boost)  in sugov_iowait_apply()
293 		sg_cpu->util = boost;  in sugov_iowait_apply()