This configuration variable will be used to build the code needed
to free empty user page table pages.

This feature is not available on all architectures yet, so
ARCH_SUPPORTS_PT_RECLAIM is needed. We can remove it once all
architectures support this feature.

Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
---
 mm/Kconfig | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/mm/Kconfig b/mm/Kconfig
index 3936fe4d26d91..c10741c54dcb1 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -1278,6 +1278,20 @@ config NUMA_EMU
 	  into virtual nodes when booted with "numa=fake=N", where N is the
 	  number of nodes. This is only useful for debugging.
 
+config ARCH_SUPPORTS_PT_RECLAIM
+	def_bool n
+
+config PT_RECLAIM
+	bool "reclaim empty user page table pages"
+	default y
+	depends on ARCH_SUPPORTS_PT_RECLAIM && MMU && SMP
+	select MMU_GATHER_RCU_TABLE_FREE
+	help
+	  Try to reclaim empty user page table pages in paths other that munmap
+	  and exit_mmap path.
+
+	  Note: now only empty user PTE page table pages will be reclaimed.
+
 source "mm/damon/Kconfig"
 
 endmenu
-- 
2.20.1

On 05.08.24 14:55, Qi Zheng wrote:
> This configuration variable will be used to build the code needed
> to free empty user page table pages.
> 
> This feature is not available on all architectures yet, so
> ARCH_SUPPORTS_PT_RECLAIM is needed. We can remove it once all
> architectures support this feature.

Please squash this into #4

-- 
Cheers,

David / dhildenb

On 2024/8/6 22:25, David Hildenbrand wrote:
> On 05.08.24 14:55, Qi Zheng wrote:
>> This configuration variable will be used to build the code needed
>> to free empty user page table pages.
>>
>> This feature is not available on all architectures yet, so
>> ARCH_SUPPORTS_PT_RECLAIM is needed. We can remove it once all
>> architectures support this feature.
> 
> Please squash this into #4

OK, will do.

>