Re: [PATCH 1/3] cgroup: define controller file conventions
From: Tejun Heo
Date: Tue Aug 04 2015 - 10:54:03 EST
Hello, Peter.
On Tue, Aug 04, 2015 at 10:48:55AM +0200, Peter Zijlstra wrote:
> > +- If a controller implements ratio based resource distribution, the
> > + control knob should be named "weight" and have the range [1, 10000]
> > + and 100 should be the default value. The values are chosen to allow
> > + enough and symmetric bias in both directions while keeping it
> > + intuitive (the default is 100%).
>
> Aside from 100% being a sane 'default', what it actually is is a unit.
> 100% == 1.
>
> So I would suggest naming the thing CGROUP_WEIGHT_UNIT := 100,
It's a minor point either way but I think people would generally find
default more familiar.
> > +/*
> > + * All weight knobs on the default hierarhcy should use the following min,
> > + * default and max values. The default value is the logarithmic center of
> > + * MIN and MAX and allows 100x to be expressed in both directions.
> > + */
> > +#define CGROUP_WEIGHT_MIN 1
> > +#define CGROUP_WEIGHT_DFL 100
> > +#define CGROUP_WEIGHT_MAX 10000
>
> That said, I'm not entirely keen on having to change this.
Yeah, changing the scale is an icky thing to do but I think the
benefits of unifying the scales across different controllers outweigh
here.
Thanks.
--
tejun
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/