Re: [PATCH 0/7] enable PT_RECLAIM on all 64-bit architectures

[David Hildenbrand (Red Hat)]

On 18.11.25 12:53, Qi Zheng wrote:
> On 11/18/25 12:53 AM, David Hildenbrand (Red Hat) wrote:
> > On 14.11.25 12:11, Qi Zheng wrote:
> > > From: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>
> > >
> > > Hi all,
> > >
> > > This series aims to enable PT_RECLAIM on all 64-bit architectures.
> > >
> > > On a 64-bit system, madvise(MADV_DONTNEED) may cause a large number of
> > > empty PTE
> > > page table pages (such as 100GB+). To resolve this problem, we need to
> > > enable
> > > PT_RECLAIM, which depends on MMU_GATHER_RCU_TABLE_FREE.
> >
> > Makes sense!
> >
> > > Therefore, this series first enables MMU_GATHER_RCU_TABLE_FREE on all
> > > 64-bit
> > > architectures, and finally makes PT_RECLAIM depend on
> > > MMU_GATHER_RCU_TABLE_FREE
> > > && 64BIT. This way, PT_RECLAIM can be enabled by default on all 64-bit
> > > architectures.
> >
> > Could we then even go ahead and stop making PT_RECLAIM user-selectable?
>
> OK, will change to:

Was more of a question: is there any scenario where we ran so far into 
issues with it?

--
Cheers

David