netdev - Re: [PATCH net 00/15] netpoll: avoid capture effects for NAPI drivers

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Message-ID: <CANn89i+dri9_d8XMcUd=+-ncFYmgDQRd4TWB93QwtoAk+ooX6g@mail.gmail.com>
Date:   Mon, 24 Sep 2018 14:05:10 -0700
From:   Eric Dumazet <edumazet@...gle.com>
To:     songliubraving@...com
Cc:     David Miller <davem@...emloft.net>,
        netdev <netdev@...r.kernel.org>, michael.chan@...adcom.com,
        Ariel Elior <ariel.elior@...ium.com>,
        Eric Dumazet <eric.dumazet@...il.com>,
        Tariq Toukan <tariqt@...lanox.com>,
        Saeed Mahameed <saeedm@...lanox.com>,
        Jeff Kirsher <jeffrey.t.kirsher@...el.com>,
        jakub.kicinski@...ronome.com, Jay Vosburgh <j.vosburgh@...il.com>,
        Veaceslav Falico <vfalico@...il.com>,
        Andy Gospodarek <andy@...yhouse.net>
Subject: Re: [PATCH net 00/15] netpoll: avoid capture effects for NAPI drivers

>
> Interesting, maybe a bnxt specific issue.
>
> It seems their model is to process TX/RX notification in the same queue,
> they throw away RX events if budget == 0
>
> It means commit e7b9569102995ebc26821789628eef45bd9840d8 is wrong and
> must be reverted.
>
> Otherwise, we have a possibility of blocking a queue under netpoll pressure.

Hmm, actually a revert might not be enough, since code at lines 2030-2031
would fire and we might not call napi_complete_done() anyway.

Unfortunately this driver logic is quite complex.

Could you test on other NIC eventually ?

Thanks.