Ray Lee wrote:
> That said, I'm willing to run my day to day life through both a swap
> prefetch kernel and a normal one. *However*, before I go through all
> the work of instrumenting the damn thing, I'd really like Andrew (or
> Linus) to lay out his acceptance criteria on the feature. Exactly what
> *should* I be paying attention to? I've suggested keeping track of
> process swapin delay total time, and comparing with and without. Is
> that reasonable? Is it incomplete?
Um, isn't it up to you?
4. Does it make anything worse? A lot or a little? Rare corner
cases, or a real world usage? Again, numbers make the case most
strongly.
I can't say I've been following this particular feature very closely,
but these are the fundamental questions that need to be dealt with in
merging any significant change. And as Nick says, historically point 4
is very important in VM tuning changes, because "obvious" improvements
have often ended up giving pathologically bad results on unexpected
workloads.