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

[Kok, Auke]

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