> On 12 Nov 1998, Zlatko Calusic wrote:
> > "David J. Fred" <djf@ic.net> writes:
> >
> > > Summary: When doing large file reads from disk the system pages
> > > unexpectedly causing moderate to severe degradation in I/O
> > > and overall system performance even though there is plenty of
> > > memory.
> >
> > Page cache is definitely too aggressive on recent kernels. I
> > developed a small patch that avoids excessive swapouts. It helps
> > kswapd to have less trouble reusing pages from page cache.
>
> Agreed, we should do something about that.
>
> > + age_page(page);
> > + age_page(page);
> > age_page(page);
>
> Do I hear "priority paging"? :))
>
> > count_max = (limit<<2) >> (priority>>1);
> > count_min = (limit<<2) >> (priority);
>
> Maybe increasing these has the same effect but with
> the advantage of keeping page aging intact.
>
Maybe, but then again maybe not.
I have a feeling that change like that could easily make kswapd a CPU
pig.
We are aging pages, so that they don't get reaped easily, and then
trying to compensate that with heavier scanning. Doesn't sound like a
good idea. Sizif's job.
But still, looks interesting, so I'm just going to compile one test
kernel with bigger count limits, for the fun's sake... :)
[Cc: Linux-MM]
Regards,
-- Posted by Zlatko Calusic E-mail: <Zlatko.Calusic@CARNet.hr> --------------------------------------------------------------------- A chicken is an egg's way of producing more eggs.- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu Please read the FAQ at http://www.tux.org/lkml/