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| author | Maíra Canal <mcanal@igalia.com> | 2024-04-22 11:18:40 -0300 |
|---|---|---|
| committer | Jonathan Corbet <corbet@lwn.net> | 2024-04-24 13:05:01 -0600 |
| commit | b413f9cd4cf0d8efd22245b960f9c162117f2762 (patch) | |
| tree | 80678b2fad5c8125ee15edf0310a0a717c3d8828 | |
| parent | 8af2d1ab78f2342f8c4c3740ca02d86f0ebfac5a (diff) | |
| download | lwn-b413f9cd4cf0d8efd22245b960f9c162117f2762.tar.gz lwn-b413f9cd4cf0d8efd22245b960f9c162117f2762.zip | |
mm: Update shuffle documentation to match its current state
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`.
Signed-off-by: Maíra Canal <mcanal@igalia.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20240422142007.1062231-1-mcanal@igalia.com
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 10 | ||||
| -rw-r--r-- | mm/Kconfig | 7 |
2 files changed, 7 insertions, 10 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 623fce7d5fcd..e6809b85b211 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -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 diff --git a/mm/Kconfig b/mm/Kconfig index b1448aa81e15..f30a18a0e37d 100644 --- a/mm/Kconfig +++ b/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. |