From: Stephen Hemminger <stephen@networkplumber.org>
To: "Carrillo, Erik G" <erik.g.carrillo@intel.com>
Cc: "Naga Harish K, S V" <s.v.naga.harish.k@intel.com>,
"dev@dpdk.org" <dev@dpdk.org>,
"stable@dpdk.org" <stable@dpdk.org>
Subject: Re: [PATCH v2 3/4] timer: fix function to stop all timers
Date: Wed, 10 Aug 2022 12:38:33 -0700 [thread overview]
Message-ID: <20220810123833.6838e009@hermes.local> (raw)
In-Reply-To: <IA1PR11MB6418A3667ECEEAF35FD5E45DB9659@IA1PR11MB6418.namprd11.prod.outlook.com>
On Wed, 10 Aug 2022 19:29:36 +0000
"Carrillo, Erik G" <erik.g.carrillo@intel.com> wrote:
> Hi Harish,
>
> > -----Original Message-----
> > From: Naga Harish K, S V <s.v.naga.harish.k@intel.com>
> > Sent: Wednesday, August 10, 2022 2:10 AM
> > To: Carrillo, Erik G <erik.g.carrillo@intel.com>
> > Cc: dev@dpdk.org; stable@dpdk.org
> > Subject: [PATCH v2 3/4] timer: fix function to stop all timers
> >
> > There is a possibility of deadlock in this API, as same spinlock is tried to be
> > acquired in nested manner.
> >
> > In timer_del function, if the previous owner and current owner lcore are
>
> It might be clearer to say something like:
>
> "If the lcore that is stopping the timer is different from the lcore that owns the timer, the timer list lock is acquired in timer_del(), even if local_is_locked is true. Because the same lock was already acquired in rte_timer_stop_all(), the thread will hang."
>
Yes, the timer owner flag acts like a lock and this is AB BA deadlock
next prev parent reply other threads:[~2022-08-10 19:38 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-03 16:26 [PATCH 3/4] timer: fix rte_timer_stop_all Naga Harish K S V
2022-08-03 17:49 ` Stephen Hemminger
2022-08-10 7:20 ` Naga Harish K, S V
2022-08-10 7:09 ` [PATCH v2 3/4] timer: fix function to stop all timers Naga Harish K S V
2022-08-10 19:29 ` Carrillo, Erik G
2022-08-10 19:38 ` Stephen Hemminger [this message]
2022-08-11 15:42 ` Naga Harish K, S V
2022-08-11 15:37 ` [PATCH v3 " Naga Harish K S V
2022-08-12 16:07 ` [PATCH v4 " Naga Harish K S V
2022-08-18 13:12 ` Carrillo, Erik G
2022-08-10 7:01 [PATCH v2 " Naga Harish K S V
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