Subject: Re: [PATCH 2/3][NET_BATCH] net core use batching

From: Bill Fink <[email-masked]>
Date: Mon, 1 Oct 2007 00:11:35 -0400

On Sun, 30 Sep 2007, jamal wrote:

> This patch adds the usage of batching within the core.
> 
> cheers,
> jamal

> [sep30-p2of3  text/plain (6.8KB)]
> [NET_BATCH] net core use batching
> 
> This patch adds the usage of batching within the core.
> The same test methodology used in introducing txlock is used, with
> the following results on different kernels:
> 
>         +------------+--------------+-------------+------------+--------+
>         |       64B  |  128B        | 256B        | 512B       |1024B   |
>         +------------+--------------+-------------+------------+--------+
> Original| 467482     | 463061       | 388267      | 216308     | 114704 |
>         |            |              |             |            |        |
> txlock  | 468922     | 464060       | 388298      | 216316     | 114709 |
>         |            |              |             |            |        |
> tg3nobtx| 468012     | 464079       | 388293      | 216314     | 114704 |
>         |            |              |             |            |        |
> tg3btxdr| 480794     | 475102       | 388298      | 216316     | 114705 |
>         |            |              |             |            |        |
> tg3btxco| 481059     | 475423       | 388285      | 216308     | 114706 |
>         +------------+--------------+-------------+------------+--------+
> 
> The first two colums "Original" and "txlock" were introduced in an earlier
> patch and demonstrate a slight increase in performance with txlock.
> "tg3nobtx" shows the tg3 driver with no changes to support batching.
> The purpose of this test is to demonstrate the effect of introducing
> the core changes to a driver that doesnt support them.
> Although this patch brings down perfomance slightly compared to txlock
> for such netdevices, it is still better compared to just the original
> kernel.
> "tg3btxdr" demonstrates the effect of using ->hard_batch_xmit() with tg3
> driver. "tg3btxco" demonstrates the effect of letting the core do all the
> work. As can be seen the last two are not very different in performance.
> The difference is ->hard_batch_xmit() introduces a new method which
> is intrusive.

Have you done performance comparisons for the case of using 9000-byte
jumbo frames?

						-Bill