Re: Help Resource Counters Scale Better (v3)

Balbir Singh
2009-08-10T05:22:49Z

* KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> [2009-08-10 09:43:44]:

> On Mon, 10 Aug 2009 09:32:29 +0900
> KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> wrote:
>
> > 1. you use res_counter_read_positive() in force_empty. It seems force_empty can
> > go into infinite loop. plz check. (especially when some pages are freed or swapped-in
> > in other cpu while force_empry runs.)
> >
> > 2. In near future, we'll see 256 or 1024 cpus on a system, anyway.
> > Assume 1024cpu system, 64k*1024=64M is a tolerance.
> > Can't we calculate max-tolerane as following ?
> >
> > tolerance = min(64k * num_online_cpus(), limit_in_bytes/100);
> > tolerance /= num_online_cpus();
> > per_cpu_tolerance = min(16k, tolelance);
> >
> > I think automatic runtine adjusting of tolerance will be finally necessary,
> > but above will not be very bad because we can guarantee 1% tolerance.
> >
>
> Sorry, one more.
>
> 3. As I requested when you pushed softlimit changes to mmotom, plz consider
> to implement a way to check-and-notify gadget to res_counter.
> See: http://marc.info/?l=linux-mm&m=124753058921677&w=2
>

Yes, I will do that, but only after the scaling, since this is more
important at the moment.