Re: Are CAP_SYS_ADMIN and CAP_SYS_NICE still needed for SQPOLL?

[Stefano Garzarella]

On Thu, Mar 25, 2021 at 08:02:45AM -0600, Jens Axboe wrote:
> On 3/25/21 7:44 AM, Pavel Begunkov wrote:
> > On 25/03/2021 11:33, Stefano Garzarella wrote:
> > > Hi Jens, Hi Pavel,
> > > I was taking a look at the new SQPOLL handling with io_thread instead of kthread. Great job! Really nice feature that maybe can be reused also in other scenarios (e.g. vhost).
> > >
> > > Regarding SQPOLL, IIUC these new threads are much closer to user threads, so is there still a need to require CAP_SYS_ADMIN and CAP_SYS_NICE to enable SQPOLL?
> >
> > Hmm, good question. If there are under same cgroup (should be in
> > theory), and if we add more scheduling points (i.e. need_resched()), and
> > don't see a reason why not. Jens?
> >
> > Better not right away though. IMHO it's safer to let the change settle
> > down for some time.
>
> Yes, agree on both counts - we are not going to need elevated privileges
> going forward, but I'd also rather defer making that change until 5.13
> so we have a bit more time on the current (new) base first.

Yeah, that makes sense to me!

Thank you both for the quick clarification,
Stefano