RE: kupdate, high CPU usage

From: Jeroen Geusebroek (Jeroen.Geusebroek@intercept.cx)
Date: Mon Jul 31 2000 - 15:44:39 EST


>> Could someone explain what kupdate and kflushd do? I have a
>> strange problem, when i ftp to my server, i get like 6500Kb/s
>> for the first then seconds. That's the same speed i get to
>> another server on the same subnet.
>>
>> But within a few seconds the CPS suddenly drops to 2500kb/s and
>> when i look at the server i see that kupdate takes 80% of the
>> cpu usage.

>This is expected behaviour. After memory is filled with
>dirty buffers, the programs writing to disk are slowed
>down to disk speeds.

That's what i also thought, only i knew the HD could handle it.

>> I tried to disable kupdate ( i searched the mailinglist on how
>> to do that ) kflushd had the same behaviour.

>*sigh* ;)

Well, it is really on the list. Search the archives :)

>> Coould some explain what could be causing the trouble? I'm using
>> the 2.2.16 kernel.

>You're slowed down to 2500kb/s either because the disk isn't
>faster or because you forgot to use hdparm to switch your
>drive to DMA mode...

Well, it was in fact the DMA problem, i was thinking about that
a few minuts after i wrote to the list. Sorry for the 'spam' :)

Greets,

Jeroen

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