Re: page pre-swapping + moving it on cache-list

[Helge Hafting <helgehaf@idb.hist.no>]

Jonathan Lundell wrote:

> The problem with thrashing, is it not, is that we're not making
> forward progress because we're waiting for swap--that is to say,
> thrashing *is* an idle state of sorts, and so might be an ideal
> opportunity for gc methods that require heavy CPU involvement. It's
> not as if there's anything better to do....

Note that trashing don't necessarily mean the cpu is free.
It can be very busy:
- deciding what to swap out next
- queuing stuff up for io, merging long elevator queues
- handling io operations, we don't all have busmastering devices

somehow I don't think garbage collection runs will be that fun
in a trashing situation.  Don't these algorithms look all over
your stack & heap for pointers?  That will surely cause lots
of io as all the apps memory is paged in so the gc algorithm
may look at it.  

Helge Hafting