Re: [patch] dubious process system time.

[Helge Hafting <helge.hafting@aitel.hist.no>]

Martin Schwidefsky wrote:
> On Thu, 2006-08-24 at 17:18 +0200, Andi Kleen wrote:
>   
>>> At the moment hardirq+softirq is just added to a random process, in
>>> general this is completely wrong. 
>>>       
>> It's better than not accounting it at all.
>>     
>
> I think it is worse than not accounting it. You are "charging" a process
> of some user for something that the user has nothing to do with.
>
>   
>>> You just need a system with a cpu hog 
>>> and an i/o bound process and you get queer results.
>>>       
>> Yes, but system load that is invisible to standard monitoring
>> tools is even worse.
>>     
>
> But it isn't invisible. cpustat->hardirq and cpustate->softirq will be
> increased. /proc/stat will show the system time spent in these two
> contexts.
>
>   
>> If you stop accounting it to random processes you have to 
>> account it somewhere else. Preferably somewhere that standard tools
>> automatically pick up.
>>     
>
> Again, why do I have to account non-process related time to a process?
> Ihmo that is completly wrong.
>   
If softirq time have to be accounted to a process (so as to not
get lost), how about accounting it to the softirqd process?  Much
more reasonable than random processes.

Helge Hafting