Re: kernel 2.4.21 , large disk write => system crawls

[Charles-Edouard Ruault <ce@ruault.com>]

Mark Hahn wrote:

>>>>when i do a large disk write operation ( copy a big file for example ), 
>>>>the whole system becomes very busy ( system goes into 99% cpu 
>>>>        
>>>>
>
>it's not write-specific.  you can see below that you're somehow
>managing to trigger roughly two interrupts per *either* bi or bo.
>for a normal IDE setup, you should see one interrupt per 16-64K
>under average use.  it's almost like your sys somehow thinks
>that it can only transfer 1 sector per interrupt!
>  
>
hmmm interesting i had not noticed that !

>  
>
>>everytime i experience a slowdown, there's a 'big' number in the io (bo) 
>>column.
>>    
>>
>
>no, it's basically in=2*(bi+bo), as if your system somehow believes
>it can only do a single sector per interrupt (PIO and -m1 perhaps?)
>it should be more like 32K per interrupt.
>
>  
>
>>Jun 27 22:52:31 charlus kernel: Found and enabled local APIC!
>>    
>>
>
>have you tried without that?
>
>.
>
>  
>
nope. I'll do that for sure. I've already had problems with APIC on 
other systems ...
Thanks for the hint. I'll keep you posted if it works.


-- 
Charles-Edouard Ruault
PGP Key ID E10C24DC