On 07/24/2015 12:58 AM, Paolo Bonzini wrote: > > > On 23/07/2015 14:59, Wen Congyang wrote: >>>> >>>> If the thread doesn't use RCU, rcu_register_thread() is harmless, is >>>> it right? >>> >>> Every rcu_register_thread() makes synchronize_rcu() a little slower. >> >> Yes, but synchronize_rcu() is very slow... > > Hmm, worse, rcu_register_thread() if called together with > synchronize_rcu() it waits for the synchronize_rcu() to finish. :/
Yes, it is a problem. Thanks Wen Congyang > > Paolo > >>> >>>>>> be simpler to add an assertion in rcu_register_thread. I'm just a bit >>>>>> wary of doing little more than the bare minimum in 2.4, because of the >>>>>> OS X failure that I didn't quite understand. >>>> Which problem? I don't find it in the maillist. >>> >>> http://article.gmane.org/gmane.comp.emulators.qemu/351548 >> >> Hmm, I guess rcu_reader is invalid when pthread key is destroyed. >> pthread key and __thread >> variable, which is destroyed first? I don't find any document to >> describe it. >