The patch titled
Subject: mm: Update shuffle documentation to match its current state
has been added to the -mm mm-unstable branch. Its filename is
mm-update-shuffle-documentation-to-match-its-current-state.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-update-shuffle-documentation-to-match-its-current-state.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: MaÃra Canal <mcanal@xxxxxxxxxx>
Subject: mm: Update shuffle documentation to match its current state
Date: Mon, 22 Apr 2024 11:18:40 -0300
Commit 839195352d82 ("mm/shuffle: remove dynamic reconfiguration") removed
the dynamic reconfiguration capabilities from the shuffle page allocator.
This means that, now, we don't have any perspective of an "autodetection
of memory-side-cache" that triggers the enablement of the shuffle page
allocator.
Therefore, let the documentation reflect that the only way to enable
the shuffle page allocator is by setting `page_alloc.shuffle=1`.
Link: https://lkml.kernel.org/r/20240422142007.1062231-1-mcanal@xxxxxxxxxx
Signed-off-by: MaÃra Canal <mcanal@xxxxxxxxxx>
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: "Huang, Ying" <ying.huang@xxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Jonathan Corbet <corbet@xxxxxxx>
Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Tejun Heo <tj@xxxxxxxxxx>
Cc: Wei Yang <richard.weiyang@xxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
Documentation/admin-guide/kernel-parameters.txt | 10 ++++------
mm/Kconfig | 7 +++----
2 files changed, 7 insertions(+), 10 deletions(-)
--- a/Documentation/admin-guide/kernel-parameters.txt~mm-update-shuffle-documentation-to-match-its-current-state
+++ a/Documentation/admin-guide/kernel-parameters.txt
@@ -4176,13 +4176,11 @@
page_alloc.shuffle=
[KNL] Boolean flag to control whether the page allocator
- should randomize its free lists. The randomization may
- be automatically enabled if the kernel detects it is
- running on a platform with a direct-mapped memory-side
- cache, and this parameter can be used to
- override/disable that behavior. The state of the flag
- can be read from sysfs at:
+ should randomize its free lists. This parameter can be
+ used to enable/disable page randomization. The state of
+ the flag can be read from sysfs at:
/sys/module/page_alloc/parameters/shuffle.
+ This parameter is only available if CONFIG_SHUFFLE_PAGE_ALLOCATOR=y.
page_owner= [KNL,EARLY] Boot-time page_owner enabling option.
Storage of the information about who allocated
--- a/mm/Kconfig~mm-update-shuffle-documentation-to-match-its-current-state
+++ a/mm/Kconfig
@@ -333,10 +333,9 @@ config SHUFFLE_PAGE_ALLOCATOR
While the randomization improves cache utilization it may
negatively impact workloads on platforms without a cache. For
- this reason, by default, the randomization is enabled only
- after runtime detection of a direct-mapped memory-side-cache.
- Otherwise, the randomization may be force enabled with the
- 'page_alloc.shuffle' kernel command line parameter.
+ this reason, by default, the randomization is not enabled even
+ if SHUFFLE_PAGE_ALLOCATOR=y. The randomization may be force enabled
+ with the 'page_alloc.shuffle' kernel command line parameter.
Say Y if unsure.
_
Patches currently in -mm which might be from mcanal@xxxxxxxxxx are
mm-update-shuffle-documentation-to-match-its-current-state.patch
