Re: Warning - running *really* short on DMA buffers while doing file

[Pedro M. Rodrigues]

Jens Axboe wrote:
> On Wed, Sep 25 2002, Mathieu Chouquet-Stringer wrote:
> 
>>	  Hello!
>>
>>I've upgraded a while to 2.4.19 and my box has been happy for the last 52
>>days (it's a dual PIII). Tonight while going through my logs, I've found
>>these:
>>
>>Sep 25 22:18:41 bigip kernel: Warning - running *really* short on DMA buffers
>>Sep 25 22:18:47 bigip last message repeated 55 times
>>Sep 25 22:19:41 bigip last message repeated 71 times
> 
> 
> This is fixed in 2.4.20-pre
> 
> 

    I reported this same problem some weeks ago - 
http://marc.theaimsgroup.com/?l=linux-kernel&m=103069116227685&w=2 . 
2.4.20pre kernels solved the error messages flooding the console, and 
improved things a bit, but system load still got very high and disk read 
and write performance was lousy. Adding more memory and using a 
completely different machine didn't help. What did? Changing the Adaptec 
scsi driver to aic7xxx_old . The performance was up 50% for writes and 
90% for reads, and the system load was acceptable. And i didn't even had 
to change the RedHat kernel (2.4.18-10) for a custom one. The storage 
was two external Arena raid boxes, btw.

Regards,
Pedro