From: Stefan Wahren <info@lategoodbye.de>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: netdev@vger.kernel.org, arnd@arndb.de
Subject: Re: Packet loss when txqueuelen is zero
Date: Mon, 30 Jun 2014 19:08:16 +0200 [thread overview]
Message-ID: <53B19980.7050606@lategoodbye.de> (raw)
In-Reply-To: <1404107363.15139.29.camel@edumazet-glaptop2.roam.corp.google.com>
Hi Eric,
Am 30.06.2014 07:49, schrieb Eric Dumazet:
> On Sun, 2014-06-29 at 15:51 +0200, Stefan Wahren wrote:
>
>> But fq_codel requires BQL in the QCA7000 network driver. Right?
>
> Not at all. 10 skb in TX ring is very small, BQL wont really help in
> this case.
>
> BQL is good for NIC with TSO support, mostly.
>
Dave Täht made the suggestion to reduce the skbs to 2. But i'm not sure
if it's a good solution, because the SPI overhead becomes bigger.
I have another idea. The QCA has an internal tx buffer something above
3000 bytes. So it would be helpful if the tx ring stores the estimated
byte size of all skbs. In the case this sum is so big that skb with a
MTU (1500 byte) won't fit into the QCA buffer, the tx queue can be stopped.
I commited my implementation [1] in the morning.
[1] -
https://github.com/I2SE/qca7000/commit/4539475a4ce1d0f5ab6ed111df9d2a9ab5f9bcc3
prev parent reply other threads:[~2014-06-30 16:51 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-28 10:59 Packet loss when txqueuelen is zero Stefan Wahren
2014-06-28 14:40 ` Eric Dumazet
2014-06-29 13:51 ` Stefan Wahren
2014-06-30 5:49 ` Eric Dumazet
2014-06-30 17:08 ` Stefan Wahren [this message]
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