Martin Schwidefsky wrote:

From: Martin Schwidefsky <redacted>
From: Hubertus Franke <redacted>
From: Himanshu Raj <redacted>

[patch 1/9] Guest page hinting: unused / free pages.

A very simple but already quite effective improvement in the handling
of guest memory vs. host memory is to tell the host when pages are
free. 

Would it be an idea to place this interface in-between the
per-cpu free page lists and the buddy allocator, so we can
move a batch of pages around at once and do the hinting in
a batched fashion ?

That way the overhead will be acceptable not just on S390
(where things are millicoded), but also on hypervisor based
virtualization like Xen.

Easy enough to pass a vector of pages to the hypervisor.

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