Re: [PATCH 1/2] NET: Multiple queue network device support

Kok, Auke
2007-02-23T19:23:24Z

Stephen Hemminger wrote:
> On Fri, 23 Feb 2007 04:00:55 -0500
> "Sreenivasa Honnur" <Sreenivasa.Honnur@neterion.com> wrote:
>
>> Fucntion "map_queue" returns queue index as '0'. There is no support to
>> return different queue indexes.
>>
>> -----Original Message-----
>> From: netdev-owner@vger.kernel.org [mailto:netdev-owner@vger.kernel.org]
>> On Behalf Of Kok, Auke
>> Sent: Friday, February 09, 2007 5:40 AM
>> To: David Miller; Garzik, Jeff; netdev@vger.kernel.org;
>> linux-kernel@vger.kernel.org
>> Cc: Kok, Auke; Peter Waskiewicz Jr; Brandeburg, Jesse; Kok, Auke;
>> Ronciak, John
>> Subject: [PATCH 1/2] NET: Multiple queue network device support
>>
>>
>> From: Peter Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
>>
>> Added an API and associated supporting routines for multiqueue network
>> devices. This allows network devices supporting multiple TX queues to
>> configure each queue within the netdevice and manage each queue
>> independantly. Changes to the PRIO Qdisc also allow a user to map
>> multiple flows to individual TX queues, taking advantage of each queue
>> on the device.
>>
>> Signed-off-by: Peter Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
>> Signed-off-by: Auke Kok <auke-jan.h.kok@intel.com>
>> ---
>
>>
>> +config NET_MULTI_QUEUE_DEVICE
>> + bool "Multiple queue network device support (EXPERIMENTAL)"
>> + depends on NET_SCHED && EXPERIMENTAL
>> + help
>> + Saying Y here will add support for network devices that have
>> more than
>> + one physical TX queue and/or RX queue.
>> +
>> + Multiple queue devices will require qdiscs that understand how
>> to
>> + queue to multiple targets. The default packet scheduler will
>> default
>> + to the first queue in a device. In other words, if you need
>> the
>> + ability to spread traffic across queues, your queueing
>> discipline
>> + needs to know how to do that.
>> +
>> + Note that saying Y here will give preferential treatment to
>> multiple
>> + queue devices in the network stack. A slight drop in
>> single-queue
>> + device performance may be seen.
>> +
>> + Say N here unless you know your network device supports
>> multiple
>> + TX and/or RX queues.
>> +
>
> This should not be a user visible configuration option.
> It should either: always be part of the kernel API
> or be selected by drivers that need/want it.

perhaps when it's stable, yes, but right now it's definately experimental and
may result in a slight overhead for single-queue devices as the text reads.

Cheers,

Auke