Re: [RFC PATCH 0/3] asynchronously scan and free empty user PTE pages

[David Hildenbrand]

On 14.06.24 05:32, Qi Zheng wrote:
> Hi David,
>
> How about starting with this:
>
> a. for MADV_DONTNEED case, try synchronous reclaim as you said
> b. for MADV_FREE case, add a madvise(MADV_PT_RECLAIM) option to mark
>      this vma, then add its corresponding mm to a global list, and then
>      traverse the list and reclaim it when the memory is tight and enters
>      the system reclaim path.
>
>      (If this option is for synchronous reclaim as you said, then the
>       user-mode program may need to start a thread to make a cyclic call.
>       I'm not sure if this usage makes sense. If so, I can also implement
>       such an option.)
> c. for s390 case you mentioned, maybe we can set a CONFIG_FREE_PT first,
>      and then s390 will not select this config until the problem is solved.

CONFIG_PT_RECLAIM or sth. like that, that would depend on 
CONFIG_ARCH_SUPPORTS_PT_RECLAIM.

Then we can start with what we know works and was tested (e.g., x86).

--
Cheers,

David / dhildenb