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

From: Kok, Auke
Date: Fri Feb 23 2007 - 14:24:15 EST


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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