On Thu, Nov 19, 2020 at 3:45 PM Mel Gorman <mgorman@xxxxxxx> wrote: > > On Thu, Nov 19, 2020 at 11:52:28AM +0800, Yafang Shao wrote: > > The 'cfs_rq' in these helpers is only used to get the rq_clock, so we > > can pass the rq_clock directly. After that, these helpers can be used by > > all sched class. > > > > Signed-off-by: Yafang Shao <laoar.shao@xxxxxxxxx> > > This introduces overhead in the general case even when schedstats is > disabled. Previously, update_stats_wait_start was a static inline so > function call overhead was avoided and schedstat_enabled() meant the > overhead was negligible. As it's now a function call, the cost of the > function entry/exit will be unconditionally hit regardless of intrest > in schedstat. > > Regardless of the merit of adding schedstats for RT, the overhead of > schedstats when stats are disabled should remain the same with the > static branch check done in an inline function. > Thanks for the explanation. I will make them inline in the next version. -- Thanks Yafang
