Re: [PATCH v2] memcg: first step towards hierarchical controller

Glauber Costa
2012-09-04T14:37:53Z

On 09/04/2012 06:35 PM, Michal Hocko wrote:
> On Tue 04-09-12 17:27:20, Glauber Costa wrote:
>> On 09/04/2012 05:09 PM, Michal Hocko wrote:
>>> Not really. Do it slowly means that somebody actually _notices_ that
>>> something is about to change and they have a lot of time for that. This
>>> will be really hard with the config option saying N by default. People
>>> will ignore that until it's too late.
>>> We are interested in those users who would keep the config default N and
>>> they are (ab)using use_hierarchy=0 in a way which is hard/impossible to
>>> fix. This is where distributions might help and they should IMHO but why
>>> to put an additional code into upstream? Isn't it sufficient that those
>>> who would like to help (and take the risk) would just take the patch?
>>
>> At least Fedora, seem to frown upon heavily at non-upstream patches.
>
> OK, so what about the following approach instead? We won't change the
> default but rather shout at people when they actually create subtrees
> with use_hierarchy==0. This shouldn't make pointless noise. I do not
> remember whether we have considered this previously so sorry if this was
> shot down as well.

The warning is fine, but just shouting won't achieve nothing. I believe
it would be really great to have a way to turn the default to 1 - and
stop the shouting.

Even if you are doing it in OpenSUSE as a patch, an upstream patch means
at least that every distribution is using the same patch, and those who
rebase will just flip the config.

I'd personally believe merging both our patches together would achieve a
good result.