> From: Stephen Hemminger [mailto:step...@networkplumber.org] > Sent: Wednesday, 20 July 2022 00.34 > > > > /** > > > @@ -179,7 +226,7 @@ rte_rwlock_write_lock(rte_rwlock_t *rwl) > > > static inline void > > > rte_rwlock_write_unlock(rte_rwlock_t *rwl) > > > { > > > - __atomic_store_n(&rwl->cnt, 0, __ATOMIC_RELEASE); > > > + __atomic_fetch_sub(&rwl->cnt, RTE_RWLOCK_WRITE, > > > __ATOMIC_RELEASE); > > > > Yes. This is correct, regardless if another writer thread is waiting > or not. (Reviewed for one writer thread using rte_rwlock_write_lock() > and another using rte_rwlock_write_trylock().) > > > > Was trying to stick to original logic. > > After writer releases want both writer and reader to be able to get in > equally. > This provide a measure of fairness (no preference) so writers can't > starve readers either.
OK; I was thinking that writers had preference. I was about to request you to document this somewhere, but you already noted it above the link to the link to the Lockless Inc. article. I didn't review the __ATOMIC_ACQUIRE/RELEASE/RELAXED access modes, but all other aspects look good. Reviewed-by: Morten Brørup <m...@smartsharesystems.com>
