Commit b413f9cd authored by Maíra Canal's avatar Maíra Canal Committed by Jonathan Corbet
Browse files

mm: Update shuffle documentation to match its current state 



Commit 83919535 ("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`.

Signed-off-by: default avatarMaíra Canal <mcanal@igalia.com>
Reviewed-by: default avatarDavid Hildenbrand <david@redhat.com>
Signed-off-by: default avatarJonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20240422142007.1062231-1-mcanal@igalia.com
parent 8af2d1ab

Documentation/admin-guide/kernel-parameters.txt

+4 −6
Original line number Diff line number Diff line
@@ -4169,13 +4169,11 @@ 


	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

mm/Kconfig

+3 −4
Original line number Diff line number Diff line
@@ -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.