[PATCH] dummy: improve performance

[PATCH] dummy: improve performance

[Catalin(ux aka Dino) BOIE]

[-- Attachment #1: Type: TEXT/PLAIN, Size: 522 bytes --]

Hello!

Attached patch tries to improve performance of dummy device by activating 
NETIF_F_SG, NETIF_F_NO_CSUM, NETIF_F_HIGHDMA, NETIF_F_FRAGLIST,
NETIF_F_TSO and NETIF_F_LLTX.

Patch compiles and runs.

I tested the speed and seems very low (both old version and the new one).
Something like 37Mbits/s. It is normal?
I can easily get 80Mbit/s on the same machine on ethernet.

Thank you!

Signed-off-by: Catalin BOIE <catab at umbrella.ro>
---
Catalin(ux aka Dino) BOIE
catab at deuroconsult.ro
http://kernel.umbrella.ro/

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--- dummy1/drivers/net/dummy.c	2005-03-26 05:28:20.000000000 +0200
+++ linux/drivers/net/dummy.c	2005-05-20 11:57:44.000000000 +0300
@@ -26,6 +26,8 @@
 			Nick Holloway, 27th May 1994
 	[I tweaked this explanation a little but that's all]
 			Alan Cox, 30th May 1994
+
+	Add special features to improve performance - Catalin BOIE
 */
 
 #include <linux/config.h>
@@ -73,6 +75,8 @@ static void __init dummy_setup(struct ne
 	dev->flags &= ~IFF_MULTICAST;
 	SET_MODULE_OWNER(dev);
 	random_ether_addr(dev->dev_addr);
+	dev->features = NETIF_F_SG | NETIF_F_NO_CSUM | NETIF_F_HIGHDMA
+			| NETIF_F_FRAGLIST | NETIF_F_TSO | NETIF_F_LLTX;
 }
 
 static int dummy_xmit(struct sk_buff *skb, struct net_device *dev)

Re: [PATCH] dummy: improve performance

[David S. Miller]

From: "Catalin(ux aka Dino) BOIE" <util@deuroconsult.ro>
Date: Fri, 20 May 2005 13:11:24 +0300 (EEST)

> I tested the speed and seems very low (both old version and the new one).
> Something like 37Mbits/s. It is normal?
> I can easily get 80Mbit/s on the same machine on ethernet.

How are you receiving packets on the dummy device for
performance testing?  This device is a transmit blackhole
and receives no packets :-)

I really don't see a real need for your patch, dummy device
performance cannot be claimed to be important at all.

Re: [PATCH] dummy: improve performance

[Catalin(ux aka Dino) BOIE]

On Wed, 25 May 2005, David S. Miller wrote:

> From: "Catalin(ux aka Dino) BOIE" <util@deuroconsult.ro>
> Date: Fri, 20 May 2005 13:11:24 +0300 (EEST)
>
>> I tested the speed and seems very low (both old version and the new one).
>> Something like 37Mbits/s. It is normal?
>> I can easily get 80Mbit/s on the same machine on ethernet.
>
> How are you receiving packets on the dummy device for
> performance testing?  This device is a transmit blackhole
> and receives no packets :-)

I only test the output part. I measure how time it takes to send an amount 
of data (icmp or udp).

> I really don't see a real need for your patch, dummy device
> performance cannot be claimed to be important at all.

Of course it's not very important.
But if someone is using it, why not at full speed?

Thanks.

---
Catalin(ux aka Dino) BOIE
catab at deuroconsult.ro
http://kernel.umbrella.ro/