Re: [RFC][PATCH][0/4] Memory controller (RSS Control)

[Balbir Singh]

Paul Menage wrote:
> On 2/19/07, Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
> > Alas, I fear this might have quite bad worst-case behaviour.  One small
> > container which is under constant memory pressure will churn the
> > system-wide LRUs like mad, and will consume rather a lot of system time.
> > So it's a point at which container A can deleteriously affect things 
> > which
> > are running in other containers, which is exactly what we're supposed to
> > not do.
>
> I think it's OK for a container to consume lots of system time during
> reclaim, as long as we can account that time to the container involved
> (i.e. if it's done during direct reclaim rather than by something like
> kswapd).
>
> Churning the LRU could well be bad though, I agree.

I completely agree with you on reclaim consuming time.

Churning the LRU can be avoided by the means I mentioned before

1. Add a container pointer (per page struct), it is also
   useful for the page cache controller
2. Check if the page belongs to a particular container before
   the list_del(&page->lru), so that those pages can be skipped.
3. Use a double LRU list by overloading the lru list_head of
   struct page.

> Paul


--
	Warm Regards,
	Balbir Singh
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