Re: [PATCH v6 00/19] selftests/mm: improve khugepaged coverage

[Andrew Morton]

On Sat, 19 Sep 2026 01:24:30 +0100 Kiryl Shutsemau <kirill@xxxxxxxxxxxxx> wrote:

> From: "Kiryl Shutsemau (Meta)" <kas@xxxxxxxxxx>
> 
> khugepaged collapses to mTHP orders since 7.2, and 7.3 added three
> selftest cases for it: the generic collapse cases run at one order named
> by -c, with the result detected by counting folios of that order.
> 
> That leaves the collapse path largely untested.  The suite does not run
> where a PMD is 512M.  A folio count cannot say where a collapse landed.
> Fixed sleeps cannot tell "not collapsed" from "not scanned yet".  And
> nothing exercises collapse under contention.
> 
> Close those gaps in order:
> 

Thanks, I've added this to mm-new.

I'd previous added v5 but it never really got testing exposure due to a
messy interaction with other changes which I didn't get onto fixing.