DMA with current 2.4.x kernels

[François Jacques]

* Ralph Siemsen <ralphs at netwinder.org> [2005-04-11 18:04:23 -0400]:

> François Jacques wrote:
> 
> >Are you using both the Tulip and NE2000 NICs?
> 
> kernel messages, so I use the NE2k on that one.  And on my gateway 
> machine I use both the Tulip and NE2k ports simultanously.

Could you please check if you have the IDE Controller' DMA enabled on it? That's how I'm using my NetWinder. We could compare the systems' config.

> All the systems except the gateway are headless, no video, mouse, 
> keyboard are connected... and no sound is used.  So the ISA bus troubles 
> don't really affect me.

Ahhh that's an excellent observation. OTOH, the ISA bus troubles are occuring
when the ISA devices are requesting DMA, which of course the keyboard and
mouse aren't doing. And video is on PCI... I would look somewhere else.

> >Yippee. I wouldn't mind going back to 2.4.19, if ReiserFS was stable on 
> >that
> >version. Well, I could try booting from the network with 2.4.19, mounting
> >/boot only and then try to enable DMA on the hard disk along with the 
> >NICs. 

I've verified my /boot partition. There's enough room on it to let me
experiment.

> Ah the esoteric filesystems :) 

Yes. And so far, its been well worth the experimentation! XFS is STRONGLY
DISCOURAGED with 2.4.27 (just doesn't work, at least on the ARM) I didn't try
JFS after Andrew's recommendations. 

ReiserFS *is* fast. It's great for squid, apache and other applications which
must access to a lot of small files simultaneously.


> Also something to check is if your HDD 
> supports DMA. 

It does. Up to UDMA6 !! Ha, brand new drives :)


> One of these day's I'll do a more recent 2.4.xx patch for netwinder ;)

With the recent release of 2.4.30, it could be a good time. But to be really
honest, what we really need is a stable 2.6 kernel.

....or everyone switching to NetBSD <grin> !


François