Re: [PATCH 0/7] enable PT_RECLAIM on all 64-bit architectures
From: David Hildenbrand (Red Hat)
Date: Mon Nov 17 2025 - 12:01:39 EST
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?
--
Cheers
David