From: Simon Horman <horms@kernel.org>
To: Kurt Kanzenbach <kurt@linutronix.de>
Cc: Jesse Brandeburg <jesse.brandeburg@intel.com>,
Tony Nguyen <anthony.l.nguyen@intel.com>,
"David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
Maciej Fijalkowski <maciej.fijalkowski@intel.com>,
Vinicius Costa Gomes <vinicius.gomes@intel.com>,
intel-wired-lan@lists.osuosl.org, netdev@vger.kernel.org
Subject: Re: [PATCH iwl-next v2] igc: Get rid of spurious interrupts
Date: Fri, 28 Jun 2024 13:59:12 +0100 [thread overview]
Message-ID: <20240628125912.GF783093@kernel.org> (raw)
In-Reply-To: <20240611-igc_irq-v2-1-c63e413c45c4@linutronix.de>
On Fri, Jun 21, 2024 at 08:56:30AM +0200, Kurt Kanzenbach wrote:
> When running the igc with XDP/ZC in busy polling mode with deferral of hard
> interrupts, interrupts still happen from time to time. That is caused by
> the igc task watchdog which triggers Rx interrupts periodically.
>
> That mechanism has been introduced to overcome skb/memory allocation
> failures [1]. So the Rx clean functions stop processing the Rx ring in case
> of such failure. The task watchdog triggers Rx interrupts periodically in
> the hope that memory became available in the mean time.
>
> The current behavior is undesirable for real time applications, because the
> driver induced Rx interrupts trigger also the softirq processing. However,
> all real time packets should be processed by the application which uses the
> busy polling method.
>
> Therefore, only trigger the Rx interrupts in case of real allocation
> failures. Introduce a new flag for signaling that condition.
>
> [1] - https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git/commit/?id=3be507547e6177e5c808544bd6a2efa2c7f1d436
>
> Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> Acked-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
> Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
> Signed-off-by: Kurt Kanzenbach <kurt@linutronix.de>
Reviewed-by: Simon Horman <horms@kernel.org>
next prev parent reply other threads:[~2024-06-28 12:59 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-06-21 6:56 [PATCH iwl-next v2] igc: Get rid of spurious interrupts Kurt Kanzenbach
2024-06-28 12:59 ` Simon Horman [this message]
2024-07-23 6:29 ` [Intel-wired-lan] " Mor Bar-Gabay
2024-07-23 15:53 ` Brett Creeley
2024-07-24 7:26 ` Kurt Kanzenbach
2024-07-24 15:30 ` Brett Creeley
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