Add documentation for the new slab_strict_numa kernel command line option

Signed-off-by: Christoph Lameter (Ampere) <cl@linux.com>

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 1518343bbe2237f1d577df5656339d6224b769be..89a4c0ec290c47034e86a71e6b7278a2acd39485 100644 (file)
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -6544,6 +6544,16 @@
        stifb=          [HW]
                        Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]]
 
+       slab_strict_numa        [MM]
+                       Support memory policies on a per object level
+                       in the slab allocator. The default is for memory
+                       policies to be applied at the folio level when
+                       a new folio is needed or a partial folio is
+                       retrieved from the lists. Increases overhead
+                       in the slab fastpaths but gains more accurate
+                       NUMA kernel object placement which helps with slow
+                       interconnects in NUMA systems.
+
         strict_sas_size=
                        [X86]
                        Format: <bool>

diff --git a/Documentation/mm/slub.rst b/Documentation/mm/slub.rst
index 60d350d08362b058dc1edc55fb50b9e7e56bcb1d..84ca1dc94e5ee0cecd59103ac010f4162ea19939 100644 (file)
--- a/Documentation/mm/slub.rst
+++ b/Documentation/mm/slub.rst
@@ -175,6 +175,15 @@ can be influenced by kernel parameters:
        ``slab_max_order`` to 0, what cause minimum possible order of
        slabs allocation.
 
+``slab_strict_numa``
+        Enables the application of memory policies on each
+        allocation. This results in more accurate placement of
+        objects which may result in the reduction of accesses
+        to remote nodes. The default is to only apply memory
+        policies at the folio level when a new folio is acquired
+        or a folio is retrieved from the lists. Enabling this
+        option reduces the fastpath performance of the slab allocator.
+
 SLUB Debug output
 =================