Re: VM in v2.4.0test9

From: Roger Larsson (roger.larsson@norran.net)
Date: Wed Oct 04 2000 - 13:38:31 EST


Rik van Riel wrote:
>
> On Wed, 4 Oct 2000, Rik van Riel wrote:
>
> > > > First, you have MORE free memory than freepages.high. In this
> > > > case I really don't see why __alloc_pages() wouldn't give the
> > > > memory to your processes ....
> > >
> > > Hmm...
> > > Can't it be a zone problem?
> > > Free pages is the total free - all zones.
> > > But suppose you want a page from a specific zone - DMA, the more
> > > memory you have the less likely that you have a DMA page free...
> > > Does all test take this into consideration?
> >
> > Free_shortage() /should/ take this into consideration, and unless
> > I'm wrong, it does ;)
>
> Also, a zone problem CANNOT cause the problem in
> David's 16MB test ...
>
> (this is getting stranger and stranger)

Now I know from where the 125 pages limit comes from.
static int zone_balance_ratio[MAX_NR_ZONES] = { 32, 128, 128, };
16M/4k/32 = 125

Probably there is a mismatch between zone->free_pages and
free_pages.{min,low,high}

/RogerL

--
Home page:
  http://www.norran.net/nra02596/
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
Please read the FAQ at http://www.tux.org/lkml/



This archive was generated by hypermail 2b29 : Sat Oct 07 2000 - 21:00:14 EST