On Fri, 2016-07-22 at 11:03 -0700, Davidlohr Bueso wrote: > On Fri, 22 Jul 2016, Waiman Long wrote: > > > I think making mutex_trylock() fail maybe a bit too far. Do we > > really > > have any real workload that cause starvation problem because of > > that. > > Code that does mutex_trylock() in a loop can certainly cause lock > > starvation, but it is not how mutex_trylock() is supposed to be > > used. > > We can't build in safeguard for all the possible abuses of the > > mutex > > APIs. > > True, and that's actually why I think that 'fixing' the > !SPIN_ON_OWNER case > is a bit too far in the first place: most of the archs that will care > about > this already have ARCH_SUPPORTS_ATOMIC_RMW. The extra code for > dealing with > this is not worth it imo.
SPIN_ON_OWNER is also disabled in case of DEBUG_MUTEXES, which is the config where I wanted to avoid starvation in the first place. --Imre