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

From: "Kok, Auke" <[email-masked]>
Date: Fri, 23 Feb 2007 11:23:12 -0800

Stephen Hemminger wrote:
> On Fri, 23 Feb 2007 04:00:55 -0500
> "Sreenivasa Honnur" <[email-masked]> wrote:
> 
>> Fucntion "map_queue" returns queue index as '0'. There is no support to
>> return different queue indexes.
>>
>> -----Original Message-----
>> From: [email-masked] [mailto:[email-masked]]
>> On Behalf Of Kok, Auke
>> Sent: Friday, February 09, 2007 5:40 AM
>> To: David Miller; Garzik, Jeff; [email-masked];
>> [email-masked]
>> 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 <[email-masked]>
>>
>> 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 <[email-masked]>
>> Signed-off-by: Auke Kok <[email-masked]>
>> ---
> 
>>  
>> +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