Re: [PATCH v9 0/5] ksm: support tracking KSM-placed zero-pages

[David Hildenbrand]

On 24.05.23 07:51, yang.yang29@xxxxxxxxxx wrote:
> From: xu xin <xu.xin16@xxxxxxxxxx>
>
> The core idea of this patch set is to enable users to perceive the number
> of any pages merged by KSM, regardless of whether use_zero_page switch has
> been turned on, so that users can know how much free memory increase is
> really due to their madvise(MERGEABLE) actions. But the problem is, when
> enabling use_zero_pages, all empty pages will be merged with kernel zero
> pages instead of with each other as use_zero_pages is disabled, and then
> these zero-pages are no longer monitored by KSM.
>
> The motivations to do this is seen at:
> https://lore.kernel.org/lkml/202302100915227721315@xxxxxxxxxx/
>
> In one word, we hope to implement the support for KSM-placed zero pages
> tracking without affecting the feature of use_zero_pages, so that app
> developer can also benefit from knowing the actual KSM profit by getting
> KSM-placed zero pages to optimize applications eventually when
> /sys/kernel/mm/ksm/use_zero_pages is enabled.


Ran the tests and they worked as expected. I only had some remaining 
feedback for the last patch, otherwise LGTM.

--
Thanks,

David / dhildenb