On Mon, Jan 15, 2024, Paul Durrant wrote: > From: Paul Durrant <pdurrant@xxxxxxxxxx> > > As described in [1] compiling with CONFIG_PROVE_RAW_LOCK_NESTING shows that > kvm_xen_set_evtchn_fast() is blocking on pfncache locks in IRQ context. > There is only actually blocking with PREEMPT_RT because the locks will > turned into mutexes. There is no 'raw' version of rwlock_t that can be used > to avoid that, so use read_trylock() and treat failure to lock the same as > an invalid cache. Are rwlocks fundamentally incapable of supporting a raw version? Because that's the only argument I see for adding a hack like this.
