Re: [PATCH] docs: update THP documentation to clarify sysfs "never" setting

[David Hildenbrand]

On 21.07.25 17:55, Lorenzo Stoakes wrote:
> Rather confusingly, setting all Transparent Huge Page sysfs settings to
> "never" does not in fact result in THP being globally disabled.
>
> Rather, it results in khugepaged being disabled, but one can still obtain
> THP pages using madvise(..., MADV_COLLAPSE).
>
> This is something that has remained poorly documented for some time, and it
> is likely the received wisdom of most users of THP that never does, in
> fact, mean never.
>
> It is therefore important to highlight, very clearly, that this is not the
> ase.
>
> Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@xxxxxxxxxx>
> ---

Can we also somehow tone down or clarify the "entirely disabled"?

Something as simple as

diff --git a/Documentation/admin-guide/mm/transhuge.rst b/Documentation/admin-guide/mm/transhuge.rst
index bd49b46398c92..2267d22277238 100644
--- a/Documentation/admin-guide/mm/transhuge.rst
+++ b/Documentation/admin-guide/mm/transhuge.rst
@@ -107,7 +107,7 @@ sysfs
 Global THP controls
 -------------------
 
-Transparent Hugepage Support for anonymous memory can be entirely disabled
+Transparent Hugepage Support for anonymous memory can be mostly disabled
 (mostly for debugging purposes) or only enabled inside MADV_HUGEPAGE
 regions (to avoid the risk of consuming more memory resources) or enabled
 system wide. This can be achieved per-supported-THP-size with one of::


--
Cheers,

David / dhildenb