On 04/16/2019 10:12 AM, Peter Zijlstra wrote: > On Sat, Apr 13, 2019 at 01:22:50PM -0400, Waiman Long wrote: >> +/* >> + * The typical HZ value is either 250 or 1000. So set the minimum waiting >> + * time to 4ms in the wait queue before initiating the handoff protocol. >> + */ >> +#define RWSEM_WAIT_TIMEOUT (HZ/250) > That seems equally unfortunate. For HZ=100 that results in 0ms, and for > HZ=300 that results in 3 1/3-rd ms. > > (and this is not considering Alpha,ARM and MIPS, who all have various > other 'creative' HZ values) > > In general aiming for sub 10ms timing using jiffies seems 'optimistic'.
I see your point. I will change it to use sched_clock() instead. Thanks, Longman
