From: Honnappa Nagarahalli <Honnappa.Nagarahalli@arm.com>
To: "Ruifeng Wang (Arm Technology China)" <Ruifeng.Wang@arm.com>
Cc: "dev@dpdk.org" <dev@dpdk.org>,
"Gavin Hu (Arm Technology China)" <Gavin.Hu@arm.com>,
nd <nd@arm.com>,
"Ruifeng Wang (Arm Technology China)" <Ruifeng.Wang@arm.com>,
"stable@dpdk.org" <stable@dpdk.org>, nd <nd@arm.com>
Subject: Re: [dpdk-stable] [PATCH] lib/rcu: fix possible spurious thread unregister
Date: Fri, 13 Sep 2019 04:17:19 +0000 [thread overview]
Message-ID: <AM6PR08MB51443F0FA5C3351C5193133498B30@AM6PR08MB5144.eurprd08.prod.outlook.com> (raw)
In-Reply-To: <20190909135142.3510-1-ruifeng.wang@arm.com>
Thanks Ruifeng, looks good.
> -----Original Message-----
> From: Ruifeng Wang <ruifeng.wang@arm.com>
> Sent: Monday, September 9, 2019 8:52 AM
> To: Honnappa Nagarahalli <Honnappa.Nagarahalli@arm.com>
> Cc: dev@dpdk.org; Gavin Hu (Arm Technology China) <Gavin.Hu@arm.com>;
> nd <nd@arm.com>; Ruifeng Wang (Arm Technology China)
> <Ruifeng.Wang@arm.com>; stable@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: stable@dpdk.org
>
> Signed-off-by: Ruifeng Wang <ruifeng.wang@arm.com>
> Reviewed-by: Gavin Hu <gavin.hu@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.nagarahalli@arm.com>
> 2.17.1
next prev parent reply other threads:[~2019-09-13 4:17 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-09 13:51 Ruifeng Wang
2019-09-13 4:17 ` Honnappa Nagarahalli [this message]
2019-09-25 8:01 ` [dpdk-stable] [dpdk-dev] " David Marchand
2019-10-18 4:11 ` David Marchand
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=AM6PR08MB51443F0FA5C3351C5193133498B30@AM6PR08MB5144.eurprd08.prod.outlook.com \
--to=honnappa.nagarahalli@arm.com \
--cc=Gavin.Hu@arm.com \
--cc=Ruifeng.Wang@arm.com \
--cc=dev@dpdk.org \
--cc=nd@arm.com \
--cc=stable@dpdk.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).