Buddyinfo shows number of contiguous pages for each order available. Since virtual machine treats host's virtual memory as its physical memory does any kernel module allocating higher order memory from buddyinfo work?


Citing rather old manuals "This file is used primarily for diagnosing memory fragmentation issues".

There's no such thing as "allocating from buddyinfo" at all.

As to "higher order memory" — I suppose you're talking about what could be referred these days as "legacy memory layout" which was valid for x86. Nowadays it's mostly gone. It's actually gone long time ago for virtualisation in particular since it's the area where access to huge amounts of RAM should be as straightforward as possible and meanwhile you can run lots of x86-based VMs the hypervisor itself would rather benefit from x86_64 mode. This circumstance clearly tells that VM's view on RAM could be absolutely irrelevant to the real state of things on the node.

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