From: Amir Vadai <amirv@mellanox.com>
To: Shawn Bohrer <sbohrer@rgmadvisors.com>
Cc: <eliezer.tamir@linux.intel.com>, <netdev@vger.kernel.org>
Subject: Re: low latency/busy poll feedback and bugs
Date: Tue, 6 Aug 2013 15:15:05 +0300 [thread overview]
Message-ID: <5200E8C9.5070808@mellanox.com> (raw)
In-Reply-To: <20130805212257.GB6904@sbohrermbp13-local.rgmadvisors.com>
On 06/08/2013 00:22, Shawn Bohrer wrote:
> I did a little testing of the new low latency/busy poll sockets today
> and found a few things that surprised me and at least one bug.
>
> 1) I'm testing with a Mellanox ConnectX-3 card.
Of course :)
> Currently polling
> with mlx4_en is broken when GRO is enabled. In
> mlx4_en_process_rx_cq() when GRO is enabled skb_mark_napi_id() is
> never called. It appears like low latency sockets with GRO is
> supposed to work because the following code checks that we are not
> ll_polling:
>
> /* This packet is eligible for GRO if it is:
> * - DIX Ethernet (type interpretation)
> * - TCP/IP (v4)
> * - without IP options
> * - not an IP fragment
> * - no LLS polling in progress
> */
> if (!mlx4_en_cq_ll_polling(cq) &&
> (dev->features & NETIF_F_GRO)) {
>
> However since we never call skb_mark_napi_id() mlx4_en_cq_ll_polling()
> will never be true.
Currently GRO and LLS are mutually exclusive, and shouldn't be used
together.
I will send a fix to make the code clearer soon.
Thanks for reporting,
Amir
prev parent reply other threads:[~2013-08-06 12:16 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-08-05 21:22 low latency/busy poll feedback and bugs Shawn Bohrer
2013-08-05 22:16 ` [PATCH net-next] net: Add low-latency/polling support for UDP multicast Shawn Bohrer
2013-08-06 7:13 ` Eliezer Tamir
2013-08-06 19:51 ` [PATCH v2 " Shawn Bohrer
2013-08-07 20:22 ` Eric Dumazet
2013-08-08 8:46 ` Eliezer Tamir
2013-08-08 23:55 ` Eric Dumazet
2013-08-11 7:59 ` Eliezer Tamir
2013-08-06 7:41 ` low latency/busy poll feedback and bugs Eliezer Tamir
2013-08-06 18:08 ` Shawn Bohrer
2013-08-06 18:25 ` Eliezer Tamir
2013-08-07 20:05 ` Ben Hutchings
2013-08-07 20:23 ` Eric Dumazet
2013-08-07 23:41 ` David Miller
2013-08-06 20:39 ` Or Gerlitz
2013-08-06 21:02 ` Eric Dumazet
2013-08-06 12:15 ` Amir Vadai [this message]
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