Re: Fairness in love and swapping

["Dr. Werner Fink" <werner@suse.de>]

[...]

> 
> but if the system would be "fair" we would get: 
> 
>           0                  5                 10            15
>       P1  <------ swapping --- like --- mad ------------------- ....
> 
>           0                  5                 10            15
>       P2  <------ swapping --- like --- mad ------------------- ....
> 
> 
> So.... In some cases, this behaviour is exactly what you want. What we
> really need is that some mechanism that actually determines in the
> first and last case that the system is thrashing like hell, and that
> "swapping" (as opposed to paging) is becoming a required
> strategy. That would mean putting a "page-in" ban on each process for
> relatively long stretches of time. These should become longer with
> each time that it occurs. That way, you will get:
> 
>           0        50           51      100
>       P1  <in memory>...........<in memory> 
> 
>           0          1        50           51      100
>       P2  ...........<in memory>...........<in memory> 
> 
> 
> By making the periods longer, you will cater for larger machines where
> getting the working set into main memory might take a long time (think
> about a machine with 4G core, and a disk subsystem that reaches 4Mb (*)
> per second on "random access paging". That's a quarter of an hour
> worth of swapping before that 3.6G process is swapped in....)

In other words: the pages swapped in or cached into the swap cache should
get their initial age which its self is calculated out of the current priority
of the corresponding process?


         Werner