Re: 2.6.4 : 100% CPU use on EIDE disk operarion, VIA chipset

Andreas Hartmann
2004-04-04T08:09:28Z

Bill Davidsen wrote:
> Andreas Hartmann wrote:
>> This is what top says during cp of 512MB-file:
>> Cpu(s): 2.0% us, 8.3% sy, 0.0% ni, 0.0% id, 89.0% wa, 0.7% hi,
>> 0.0% si
>>
>> New is "wa", what probably means "wait". This value is very high as long
>> as the HD is writing or reading datas:
>>
>> cp dummy /dev/null
>> produces this top-line:
>> Cpu(s): 3.0% us, 5.3% sy, 0.0% ni, 0.0% id, 91.0% wa, 0.7% hi,
>> 0.0% si
>
> Yes "wa" is not intuitive, some other operating systems use "wio" for
> "wait i/o" time. As noted in the other thread, you can try the deadline
> elevator or increased readahead for your load.

If the processor and the kernel could do other things during wa, like
compiling e.g., it would be no problem. But it seems to be, that this is
not possible. Or did I oversee something?

Regards,
Andreas Hartmann