On 6 May 2021, at 11:40, David Hildenbrand wrote:

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The last patch increases SECTION_SIZE_BITS to demonstrate the use of memory
hotplug/hotremove subsection, but is not intended to be merged as is. It is
there in case one wants to try this out and will be removed during the final
submission.

Feel free to give suggestions and comments. I am looking forward to your
feedback.

Please not like this.

Do you mind sharing more useful feedback instead of just saying a lot of No?

I remember reasoning about this already in another thread, no? Either you're ignoring my previous feedback or my mind is messing with me.

I definitely remember all your suggestions:

1. do not use CMA allocation for 1GB THP.
2. section size defines the minimum size in which we can add_memory(), so we cannot increase it.

I am trying an alternative here. I am not using CMA allocation and not increasing the minimum size of add_memory() by decoupling the memory block size from section size, so that add_memory() can add a memory block smaller (as small as 2MB, the subsection size) than section size. In this way, section size can be increased freely. I do not see the strong tie between add_memory() and section size, especially we have subsection bitmap support.


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Best Regards,
Yan Zi