Il ven 23 dic 2022, 16:54 Peter Xu <pet...@redhat.com> ha scritto: > > This is not valid because the transaction could happen in *another* > thread. > > In that case memory_region_transaction_depth() will be > 0, but RCU is > > needed. > > Do you mean the code is wrong, or the comment? Note that the code has > checked rcu_read_locked() where introduced in patch 1, but maybe something > else was missed? >
The assertion is wrong. It will succeed even if RCU is unlocked in this thread but a transaction is in progress in another thread. Perhaps you can check (memory_region_transaction_depth() > 0 && !qemu_mutex_iothread_locked()) || rcu_read_locked() instead? Paolo Thanks, > > -- > Peter Xu > >
