Re: [PATCH v2 0/4] fix unexpected type conversions and potential overflows

From: Harry Yoo (Oracle)

Date: Thu Mar 26 2026 - 03:54:58 EST


On Thu, Mar 26, 2026 at 08:14:36AM +0100, Michal Hocko wrote:
> On Wed 25-03-26 22:13:21, Qi Zheng wrote:
> > From: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>
> >
> > Hi all,
> >
> > As Harry Yoo pointed out [1], in scenarios where massive state updates occur
> > (e.g., during the reparenting of LRU folios), the values passed to memcg stat
> > update functions can accumulate and exceed the upper limit of a 32-bit integer.
>
> Is this a real problem without reparenting? In other words is this a
> follow up for that work or something that we need on its own?

This is not a problem (as discussed in [1]) without reparenting.
[1] https://lore.kernel.org/linux-mm/138d9363-ab0c-4f5c-bedc-b326f5aaee91@xxxxxxxxx

--
Cheers,
Harry / Hyeonggon