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

[Tejun Heo]

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.

> 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.

-- 
tejun