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

[Qi Zheng]

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:

config PT_RECLAIM
	def_bool y
	depends on MMU_GATHER_RCU_TABLE_FREE && MMU && SMP && 64BIT

>