Re: VIA IDE performance under 2.6.0-test7/8?

[James Courtier-Dutton <James@superbug.demon.co.uk>]

James Finnie wrote:
> Hi guys;
> 
> Am having trouble getting decent IDE performance from the 2.6.0-test8 kernel
> (tested with 2.6.0-test7 kernel also, same issue).  The platform is VIA
> EPIA-ME6000 - with a VIA VT8235 southbridge.  Under 2.4.21 I get around
> 40Mb/s in hdparm -t and 70Mb/s for hdparm -T.  Under the 2.6.0-test7/8 I
> only manage 13Mb/s & 52Mb/s respectively!  I've attached my .config, and the
> output of /proc/ide/via, dmesg, and hdparm info.  I don't think I'm doing
> anything particularly stupid here, but if I am, hit me with a wet fish
> please :)
> 
> Thanks for all help,
> 
> James
> 
Can you also send the output from "cat /proc/interrupts".
It looks like you are not using IO-APIC, but instead using XT-PIC.
XT-PIC is a lot slower than IO-APIC.

Just turn on SMB support in the "make menuconf", and it should enable 
IO-APIC.

If you cannot boot using IO-APIC, you probably have one of the bad VIA 
motherboards. I have not determined if the IO-APIC issues with VIA 
VT8235 MBs is hardware or software related. All I know, is some VIA 
VT8235 MBs work, and some don't. I am still investigating why.

Cheers

James