slub: Make cpu partial slab support configurable

CPU partial support can introduce level of indeterminism that is not
wanted in certain context (like a realtime kernel). Make it
configurable.

This patch is based on Christoph Lameter's "slub: Make cpu partial slab
support configurable V2".

Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>

1 files changed, 11 insertions, 0 deletions

diff --git a/init/Kconfig b/init/Kconfig
index 7d30240e5bfe..3b34a88cf34e 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1511,6 +1511,17 @@ config SLOB
 
 endchoice
 
+config SLUB_CPU_PARTIAL
+        default y
+        depends on SLUB
+        bool "SLUB per cpu partial cache"
+        help
+          Per cpu partial caches accellerate objects allocation and freeing
+          that is local to a processor at the price of more indeterminism
+          in the latency of the free. On overflow these caches will be cleared
+          which requires the taking of locks that may cause latency spikes.
+          Typically one would choose no for a realtime system.
+
 config MMAP_ALLOW_UNINITIALIZED
         bool "Allow mmapped anonymous memory to be uninitialized"
         depends on EXPERT && !MMU