On Tue, Feb 20, 2024 at 02:15:42PM +0800, zhaoyang.huang wrote: > From: Zhaoyang Huang <zhaoyang.huang@xxxxxxxxxx> > > According to current policy, CFS's may suffer involuntary IO-latency by > being preempted by RT/DL tasks or IRQ since they possess the privilege for > both of CPU and IO scheduler. What is 'current policy', what is CFS, what is RT/DL? What privilege is possessed? > 1. All types of sched class's load(util) are tracked and calculated in the > same way(using a geometric series which known as PELT) > 2. Keep the legacy policy by NOT adjusting rq's position in fifo_list > but only make changes over expire_time. > 3. The fixed expire time(hundreds of ms) is in the same range of cpu > avg_load's account series(the utilization will be decayed to 0.5 in 32ms) What problem does this fix, i.e. what performance number are improved or what other effects does it have? > + * The expire time is adjusted via calculating the proportion of > + * CFS's activation among whole cpu time during last several > + * dazen's ms.Whearas, this would NOT affect the rq's position in > + * fifo_list but only take effect when this rq is checked for its > + * expire time when at head. > */ Please speel check the comment and fix the formatting to have white spaces after sentences and never exceed 80 characters in block comments.
