Thanks Ruifeng, looks good.
> -----Original Message-----
> From: Ruifeng Wang <ruifeng.w...@arm.com>
> Sent: Monday, September 9, 2019 8:52 AM
> To: Honnappa Nagarahalli <honnappa.nagaraha...@arm.com>
> Cc: dev@dpdk.org; Gavin Hu (Arm Technology China) <gavin...@arm.com>;
> nd <n...@arm.com>; Ruifeng Wang (Arm Technology China)
> <ruifeng.w...@arm.com>; sta...@dpdk.org
> Subject: [PATCH] lib/rcu: fix possible spurious thread unregister
>
> Thread unregister returns success while unregister not been performed.
> This is due to incorrect thread registration status check.
> Fix this issue by correcting bitmap check.
>
> Fixes: 64994b56cfd7 ("rcu: add RCU library supporting QSBR mechanism")
> Cc: sta...@dpdk.org
>
> Signed-off-by: Ruifeng Wang <ruifeng.w...@arm.com>
> Reviewed-by: Gavin Hu <gavin...@arm.com>
> ---
> lib/librte_rcu/rte_rcu_qsbr.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/lib/librte_rcu/rte_rcu_qsbr.c b/lib/librte_rcu/rte_rcu_qsbr.c
> index
> ce7f93dd3..8c37c88cd 100644
> --- a/lib/librte_rcu/rte_rcu_qsbr.c
> +++ b/lib/librte_rcu/rte_rcu_qsbr.c
> @@ -158,7 +158,7 @@ rte_rcu_qsbr_thread_unregister(struct rte_rcu_qsbr
> *v, unsigned int thread_id)
> /* Check if the thread is already unregistered */
> old_bmap = __atomic_load_n(__RTE_QSBR_THRID_ARRAY_ELM(v, i),
> __ATOMIC_RELAXED);
> - if (old_bmap & ~(1UL << id))
> + if (!(old_bmap & (1UL << id)))
> return 0;
>
> do {
> @@ -175,7 +175,7 @@ rte_rcu_qsbr_thread_unregister(struct rte_rcu_qsbr
> *v, unsigned int thread_id)
> if (success)
> __atomic_fetch_sub(&v->num_threads,
> 1, __ATOMIC_RELAXED);
> - else if (old_bmap & ~(1UL << id))
> + else if (!(old_bmap & (1UL << id)))
> /* Someone else unregistered this thread.
> * Counter should not be incremented.
> */
> --
Reviewed-by: Honnappa Nagarahalli <honnappa.nagaraha...@arm.com>
> 2.17.1
