Messages in this thread | | | Date | Tue, 6 Feb 2024 20:17:28 -0800 | Subject | Re: [PATCH v12 17/20] KVM: xen: don't block on pfncache locks in kvm_xen_set_evtchn_fast() | From | Sean Christopherson <> |
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On Mon, Jan 15, 2024, Paul Durrant wrote: > From: Paul Durrant <pdurrant@amazon.com> > > 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.
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