Re: [igb] netconsole triggers warning in netpoll_poll_dev

From: Alexander Duyck <alexander.duyck@gmail.com>
To: Jakub Kicinski <kuba@kernel.org>
Cc: Oleksandr Natalenko <oleksandr@natalenko.name>,
	linux-kernel@vger.kernel.org,
	Jesse Brandeburg <jesse.brandeburg@intel.com>,
	Tony Nguyen <anthony.l.nguyen@intel.com>,
	"David S. Miller" <davem@davemloft.net>,
	intel-wired-lan@lists.osuosl.org, netdev@vger.kernel.org
Subject: Re: [igb] netconsole triggers warning in netpoll_poll_dev
Date: Wed, 7 Apr 2021 09:25:28 -0700	[thread overview]
Message-ID: <CAKgT0UfLLQycLsAZQ98ofBGYPwejA6zHbG6QsNrU92mizS7e0g@mail.gmail.com> (raw)
In-Reply-To: <20210407083748.56b9c261@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com>

On Wed, Apr 7, 2021 at 8:37 AM Jakub Kicinski <kuba@kernel.org> wrote:
>
> On Wed, 7 Apr 2021 08:00:53 +0200 Oleksandr Natalenko wrote:
> > Thanks for the effort, but reportedly [1] it made no difference,
> > unfortunately.
> >
> > [1] https://bugzilla.kernel.org/show_bug.cgi?id=212573#c8
>
> The only other option I see is that somehow the NAPI has no rings.
>
> diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
> index a45cd2b416c8..24568adc2fb1 100644
> --- a/drivers/net/ethernet/intel/igb/igb_main.c
> +++ b/drivers/net/ethernet/intel/igb/igb_main.c
> @@ -7980,7 +7980,7 @@ static int igb_poll(struct napi_struct *napi, int budget)
>         struct igb_q_vector *q_vector = container_of(napi,
>                                                      struct igb_q_vector,
>                                                      napi);
> -       bool clean_complete = true;
> +       bool clean_complete = q_vector->tx.ring || q_vector->rx.ring;
>         int work_done = 0;
>
>  #ifdef CONFIG_IGB_DCA

It might make sense to just cast the work_done as a unsigned int, and
then on the end of igb_poll use:
  return min_t(unsigned int, work_done, budget - 1);