Interesting analysis of linux kernel threading by IBM

[Davide Libenzi]

On Fri, 21 Jan 2000, Horst von Brand wrote:
> > But the fact is that normally 2 tasks switches at a very lower factor then
> > 300.
> 
> Why? That depends mostly on the tasks, and if the tasks are the same, this
> should not change very much (unless the machine is swamped with interrupts,
> and then your problem is another one).
If You have a great number of processes running on a system, some of them 
probably are processing ( feeding the runqueue ) while others, if You exclude 
tasks that do nothing but "for(;;)", are stressing devices plugged on Your
system ( disks, netcards, serials, etc ..).
These devices are highly susceptible to stress, and it defends Yourself firing
interrupts.
Now highly is the number of processes running on Your system higher is the
number of tasks stressing devices, and this stress reflect an high number of
interrupts == switches.

Davide.

-- 
All this stuff is IMVHO



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