Re: [RFC 02/18] cgroup_pids: track maximum pids

[Topi Miettinen <toiwoton-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]

On 06/13/16 21:33, Tejun Heo wrote:
> Hello,
> 
> On Mon, Jun 13, 2016 at 09:29:32PM +0000, Topi Miettinen wrote:
>> I used fork callback as I don't want to lower the watermark in all cases
>> where the charge can be lowered, so I'd update the watermark only when
>> the fork really happens.
> 
> I don't think that would make a noticeable difference.  That's where
> we decide whether to grant fork or not after all and thus where the
> actual usage is.

I tried using only charge functions, but then the result was too low.
With fork callback, the result was as expected.

-Topi

> 
>> Is there a better way to compare and set? I don't think atomic_cmpxchg()
>> does what's needed,
> 
> cmpxchg loop should do what's necessary although I'm not sure how much
> being strictly correct matters here.
> 
> Thanks.
>