From: Noam Camus <noamc@ezchip.com>
To: David Miller <davem@davemloft.net>
CC: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
        "Alexey.Brodkin@synopsys.com" <Alexey.Brodkin@synopsys.com>,
        "vgupta@synopsys.com" <vgupta@synopsys.com>,
        Tal Zilcer <talz@ezchip.com>
Subject: RE: [v1 0/6] *** nps_enet fixups ***
Thread-Topic: [v1 0/6] *** nps_enet fixups ***
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Date: Tue, 18 Aug 2015 05:04:20 +0000
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 <20150817.103607.1737876155019074073.davem@davemloft.net>
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From: David Miller [mailto:davem@davemloft.net] 
Sent: Monday, August 17, 2015 8:36 PM


> You should not move TX completion out of NAPI handling, NAPI poll is exactly where it belongs.
>
> If you handle it in hardware interrupt context you have to use
> dev_kfree_skb_irq() which defers the operation to software interrupt context anyways and is thus expensive.

> Whereas if you keep TX completion in your NAPI handler the kfree is handled synchronously and efficiently, as well as making SKB's potentially available for RX reclaim.

I followed "Hardware Architecture" section from:
http://www.linuxfoundation.org/collaborate/workgroups/networking/napi
and came up with "reduce processing latency" idea.

Anyway, I will restore TX completion back to NAPI poll.

> I'm not applying this series, you are doing with TX handling exactly what we tell people not to do.

I will come up with revised series in v2.

Noam
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