Commit 652e1a51 authored by Maíra Canal's avatar Maíra Canal Committed by Andrew Morton
Browse files

mm: fix docs for the kernel parameter ``thp_anon=`` 

If we add ``thp_anon=32,64K:always`` to the kernel command line, we
will see the following error:

[    0.000000] huge_memory: thp_anon=32,64K:always: error parsing string, ignoring setting

This happens because the correct format isn't ``thp_anon=<size>,<size>[KMG]:<state>```,
as [KMG] must follow each number to especify its unit. So, the correct
format is ``thp_anon=<size>[KMG],<size>[KMG]:<state>```.

Therefore, adjust the documentation to reflect the correct format of the
parameter ``thp_anon=``.

Link: https://lkml.kernel.org/r/20241101165719.1074234-3-mcanal@igalia.com


Fixes: dd4d30d1 ("mm: override mTHP "enabled" defaults at kernel cmdline")
Signed-off-by: default avatarMaíra Canal <mcanal@igalia.com>
Acked-by: default avatarBarry Song <baohua@kernel.org>
Acked-by: default avatarDavid Hildenbrand <david@redhat.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Lance Yang <ioworker0@gmail.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 4401e9d1

Documentation/admin-guide/kernel-parameters.txt

+1 −1
Original line number Diff line number Diff line
@@ -6688,7 +6688,7 @@ 
			0: no polling (default)



	thp_anon=	[KNL]

			Format: <size>,<size>[KMG]:<state>;<size>-<size>[KMG]:<state>

			Format: <size>[KMG],<size>[KMG]:<state>;<size>[KMG]-<size>[KMG]:<state>

			state is one of "always", "madvise", "never" or "inherit".

			Control the default behavior of the system with respect

			to anonymous transparent hugepages.

Documentation/admin-guide/mm/transhuge.rst

+1 −1
Original line number Diff line number Diff line
@@ -303,7 +303,7 @@ control by passing the parameter ``transparent_hugepage=always`` or 
kernel command line.



Alternatively, each supported anonymous THP size can be controlled by

passing ``thp_anon=<size>,<size>[KMG]:<state>;<size>-<size>[KMG]:<state>``,

passing ``thp_anon=<size>[KMG],<size>[KMG]:<state>;<size>[KMG]-<size>[KMG]:<state>``,

where ``<size>`` is the THP size (must be a power of 2 of PAGE_SIZE and

supported anonymous THP)  and ``<state>`` is one of ``always``, ``madvise``,

``never`` or ``inherit``.