From: "ezequiel.garcia@free-electrons•com" <ezequiel.garcia@free-electrons•com>
To: Eric Dumazet <eric.dumazet@gmail•com>
Cc: David Laight <David.Laight@ACULAB•COM>,
"'fugang.duan@freescale•com'" <fugang.duan@freescale•com>,
"Frank.Li@freescale•com" <Frank.Li@freescale•com>,
"davem@davemloft•net" <davem@davemloft•net>,
"netdev@vger•kernel.org" <netdev@vger•kernel.org>,
"shawn.guo@linaro•org" <shawn.guo@linaro•org>,
"bhutchings@solarflare•com" <bhutchings@solarflare•com>,
"stephen@networkplumber•org" <stephen@networkplumber•org>
Subject: Re: [PATCH v1 4/6] net: fec: Increase buffer descriptor entry number
Date: Fri, 30 May 2014 13:35:15 -0300 [thread overview]
Message-ID: <20140530163515.GA10354@arch.cereza> (raw)
In-Reply-To: <1401465492.3645.122.camel@edumazet-glaptop2.roam.corp.google.com>
On 30 May 08:58 AM, Eric Dumazet wrote:
> On Fri, 2014-05-30 at 15:34 +0000, David Laight wrote:
>
> > Software TSO generates lots of separate ethernet frames, there is no
> > absolute requirement to be able to put all of them into the tx ring at once.
>
> Yes there is absolute requirement. It is driver responsibility to block
> the queue if the available slots in TX ring would not allow the
> following packet to be sent.
>
> Thats why a TSO emulation needs to set gso_max_segs to some sane value
>
> (sfc sets it to 100)
>
> In Fugang patch this part was a wrong way to deal with this :
>
> + if (tso_count_descs(skb) >= fec_enet_txdesc_entry_free(fep)) {
> + if (net_ratelimit())
> + netdev_err(ndev, "tx queue full!\n");
> + return NETDEV_TX_BUSY;
> + }
> +
>
> This was copy/pasted from buggy
> drivers/net/ethernet/marvell/mv643xx_eth.c
>
Indeed. I'm just about to submit the fixes for those, which may be useful to
fix it in this driver as well.
--
Ezequiel García, Free Electrons
Embedded Linux, Kernel and Android Engineering
http://free-electrons.com
next prev parent reply other threads:[~2014-05-30 16:35 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-30 2:05 [PATCH v1 0/6] *** net: fec: Enable Software TSO to improve the tx performance *** Fugang Duan
2014-05-30 2:05 ` [PATCH v1 1/6] net: fec: Factorize the .xmit transmit function Fugang Duan
2014-05-30 2:05 ` [PATCH v1 2/6] net: fec: Enable IP header hardware checksum Fugang Duan
2014-05-30 2:05 ` [PATCH v1 3/6] net: fec: Factorize feature setting Fugang Duan
2014-05-30 2:05 ` [PATCH v1 4/6] net: fec: Increase buffer descriptor entry number Fugang Duan
2014-05-30 9:10 ` David Laight
2014-05-30 9:42 ` fugang.duan
2014-05-30 13:13 ` Eric Dumazet
2014-05-30 14:01 ` ezequiel.garcia
2014-05-30 14:54 ` Eric Dumazet
2014-05-30 15:08 ` fugang.duan
2014-05-30 15:34 ` David Laight
2014-05-30 15:52 ` fugang.duan
2014-05-30 15:58 ` Eric Dumazet
2014-05-30 16:35 ` ezequiel.garcia [this message]
2014-05-30 15:40 ` Eric Dumazet
2014-05-30 15:46 ` fugang.duan
2014-05-30 2:05 ` [PATCH v1 5/6] net: fec: Add Scatter/gather support Fugang Duan
2014-05-30 4:37 ` Eric Dumazet
2014-05-30 4:48 ` fugang.duan
2014-05-30 14:26 ` Frank.Li
2014-05-30 2:05 ` [PATCH v1 6/6] net: fec: Add software TSO support Fugang Duan
2014-05-30 6:30 ` Eric Dumazet
2014-05-30 7:16 ` fugang.duan
2014-05-30 16:21 ` Eric Dumazet
2014-06-01 0:55 ` fugang.duan
2014-06-01 1:39 ` Eric Dumazet
2014-06-01 2:25 ` fugang.duan
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