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: dd4d30d1cd ("mm: override mTHP "enabled" defaults at kernel cmdline")
Signed-off-by: Maíra Canal <mcanal@igalia.com>
Acked-by: Barry Song <baohua@kernel.org>
Acked-by: David 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: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Maíra Canal 2024-11-01 13:54:05 -03:00 committed by Andrew Morton
parent 4401e9d10a
commit 652e1a5146
2 changed files with 2 additions and 2 deletions

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@ -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.

View File

@ -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``.