Merge branch 'x86-bsp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

[deliverable/linux.git] / mm / Kconfig

diff --git a/mm/Kconfig b/mm/Kconfig
index a3f8dddaaab3f08de3bc6c63921be614bbae6736..e6651c5de14f4e42a0b6455e0d0b0859f06c2680 100644 (file)
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -187,6 +187,21 @@ config SPLIT_PTLOCK_CPUS
        default "999999" if DEBUG_SPINLOCK || DEBUG_LOCK_ALLOC
        default "4"
 
+#
+# support for memory balloon compaction
+config BALLOON_COMPACTION
+       bool "Allow for balloon memory compaction/migration"
+       def_bool y
+       depends on COMPACTION && VIRTIO_BALLOON
+       help
+         Memory fragmentation introduced by ballooning might reduce
+         significantly the number of 2MB contiguous memory blocks that can be
+         used within a guest, thus imposing performance penalties associated
+         with the reduced number of transparent huge pages that could be used
+         by the guest workload. Allowing the compaction & migration for memory
+         pages enlisted as being part of memory balloon devices avoids the
+         scenario aforementioned and helps improving memory defragmentation.
+
 #
 # support for memory compaction
 config COMPACTION