Re: Linux 2.4.1-ac7

[Marcelo Tosatti]

On Tue, 13 Feb 2001, Rik van Riel wrote:

> On Tue, 13 Feb 2001, Mike Galbraith wrote:
> > On Mon, 12 Feb 2001, Marcelo Tosatti wrote:
> >
> > > Could you please try the attached patch on top of latest Rik's patch?
> >
> > Sure thing.. (few minutes later) no change.
> 
> That's because your problem requires a change to the
> balancing between swap_out() and refill_inactive_scan()
> in refill_inactive()...
> 
> The big problem here is that no matter which magic
> proportion between the two functions we use, it'll always
> be wrong for a large proportion of the people out there.
> 
> This means we need to have a good way to auto-tune this
> thing. I'm thinking of letting swap_out() start out way
> less active than refill_inactive_scan() with extra calls
> to swapout being made from refill_inactive_scan when we
> think it's needed...
> 
> (... I'm writing a patch right now ...)

We're using nr_async_pages to calculate the number of pages which should
be flushed, but nr_async_pages counts on flight swap _readaheads_ (each
swapin increases nr_async_pages by (1 << page_cluster)) and writes, not
only writes.

That makes the "pageout free shortage and sleep" kswapd behaviour you
wanted a bit messy.