From: Stephen Hemminger <stephen@networkplumber.org>
To: Changchun Zhang <changchun.zhang@oracle.com>
Cc: "Van Haaren, Harry" <harry.van.haaren@intel.com>,
NAGENDRA BALAGANI <nagendra.balagani@oracle.com>,
"users@dpdk.org" <users@dpdk.org>
Subject: Re: [External] : Re: Query Regarding Race Condition Between Packet Reception and Device Stop in DPDK
Date: Mon, 17 Feb 2025 11:06:52 -0800 [thread overview]
Message-ID: <20250217110652.2f3eb077@hermes.local> (raw)
In-Reply-To: <CO1PR10MB475637CF7A1B9548E765958584FB2@CO1PR10MB4756.namprd10.prod.outlook.com>
On Mon, 17 Feb 2025 18:57:00 +0000
Changchun Zhang <changchun.zhang@oracle.com> wrote:
> Hi Harry,
>
> Can we call rte_eth_dev_rx_queue_stop() on a rx queue when a fast path is still polling the queue? The sequence on control and fast path cores would like:
> Control path:
> rte_eth_dev_rx_queue_stop(rx_queue_id);
> ...waiting for draining of rx_queue...
> rte_eth_dev_stop()
> ....
>
> Fast path:
> Keep calling rte_eth_rx_burst()
> (I am expecting it will return 0 if queue is already drained and stopped)
>
No.
The application needs to not call rx_burst when stop is being done.
There rx_burst is a fast path with no additional checks and is intentionally not thread safe.
You need to coordinate queue management inside the application.
next prev parent reply other threads:[~2025-02-17 19:06 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-02-14 8:43 NAGENDRA BALAGANI
2025-02-14 9:22 ` Van Haaren, Harry
2025-02-14 16:31 ` Stephen Hemminger
2025-02-17 9:32 ` [External] : " NAGENDRA BALAGANI
2025-02-17 18:57 ` Changchun Zhang
2025-02-17 19:06 ` Stephen Hemminger [this message]
2025-02-17 19:14 ` Changchun Zhang
2025-02-17 19:20 ` Changchun Zhang
2025-02-17 20:56 ` Stephen Hemminger
2025-02-18 9:32 ` Van Haaren, Harry
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