Re: [PATCH 1/1] cgroup-v1: Grant CAP_SYS_NICE holders permission to move tasks between cgroups

[John Stultz]

On Mon, Oct 4, 2021 at 9:57 AM Suren Baghdasaryan <surenb@xxxxxxxxxx> wrote:
> On Mon, Oct 4, 2021 at 9:41 AM Tejun Heo <tj@xxxxxxxxxx> wrote:
> > On Thu, Sep 30, 2021 at 02:20:53PM -0700, Suren Baghdasaryan wrote:
> > > Some of the controllers are moving to cgroup v2 but not all of them
> > > are there yet. For example, there are still some issues with moving
> > > the cpu controller to v2 which I believe were discussed during Android
> > > Microconference at LPC 2021.
> >
> > Care to provide a summary?
>
> Unfortunately I could not be present at LPC this year but Wei I
> believe was the presenter (CC'ing him).
> Wei, could you please summarize the issues with moving the cpu
> controller to cgroups v2?

Tejun: We were sorry you didn't join as we were hoping for your
attendance for the discussion!

For reference, here's the video of the session:
  https://www.youtube.com/watch?v=O_lCFGinFPM&t=2941s

And continued discussion from the BoF:
  https://youtu.be/i5BdYn6SNQc?t=703

But Wei can still chime in with a more focused summary, maybe?


> Also CC'ing John, who I believe tried to upstream this patch before.

We sort of went in a big circle of creating a config time option w/
CAP_SYS_NICE, then a new CAP_CGROUP_MIGRATE then switching to
CAP_SYS_RESOURCE and then back to CAP_CGROUP_MIGRATE, and when that
was panned I gave up and we kept the small patch in the Android tree
that uses CAP_SYS_NICE.

Links to previous attempts & discussion:
v1: https://lore.kernel.org/lkml/1475556090-6278-1-git-send-email-john.stultz@xxxxxxxxxx/#t
v2: https://lore.kernel.org/lkml/1476743724-9104-1-git-send-email-john.stultz@xxxxxxxxxx/
v4: https://lore.kernel.org/lkml/1478647728-30357-1-git-send-email-john.stultz@xxxxxxxxxx/
v5: https://lore.kernel.org/lkml/1481593143-18756-1-git-send-email-john.stultz@xxxxxxxxxx/

thanks
-john