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Re: Re: Help with hdparm



On 28.08.2002 18:57:42 bob wrote:

> am slow too.  But with a locally recompiled kernel things are fast.  I
> don't know if the SMP flag is the difference or not.
> 
> hdparm -t /dev/hda
> 
>  Timing buffered disk reads:  64 MB in  7.60 seconds =  8.42 MB/sec
> 
> hdparm /dev/hda
> 
> /dev/hda:
[...]
>  I/O support  =  1 (32-bit)
>  unmaskirq    =  1 (on)
>  using_dma    =  0 (off)
[...]
> But if I boot back to the kernel that I recompiled then I get the
> results I reported previously.  The configuration for which I reported
> is the /boot/config-2.4.18-bf2.4 plus CONFIG_NOHIGHMEM=y and
> CONFIG_SMP=y.  I did not mean to set SMP but since my main machine is
> an SMP machine I must have set that out of habit.  Then it was
> recompiled with CONFIG_M386=y because I did not change that from bf24,
> which is silly, I will change that to get better optimizations.
[...]
> 
> When I get time I will rebuild the kernel without SMP, and with better
> optimizations and post the results.

It is not the SMP Flag.
You do not have activated DMA in this kernel (using_dma = 0 (off))
This can be done with a kernel append line or via hdparm utility.
That's not my problem. I can switch this on. But with the faster UDMA 
modes 
my kernel reports IO errors and after a short while nothing goes on.
I have to switch back to slower MultiWordDMA manually.

Can you report me, which North/South-Bridge you have on your FIC SD-11 
Board.
Perhaps there is our difference.

Thx



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