gpio: pca953x: add a comment explaining the need for a lockdep subclass

[cascardo/linux.git] / mm / Kconfig

diff --git a/mm/Kconfig b/mm/Kconfig
index 78a23c5..be0ee11 100644 (file)
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -262,7 +262,14 @@ config COMPACTION
        select MIGRATION
        depends on MMU
        help
-         Allows the compaction of memory for the allocation of huge pages.
+          Compaction is the only memory management component to form
+          high order (larger physically contiguous) memory blocks
+          reliably. The page allocator relies on compaction heavily and
+          the lack of the feature can lead to unexpected OOM killer
+          invocations for high order memory requests. You shouldn't
+          disable this option unless there really is a strong reason for
+          it and then we would be really interested to hear about that at
+          linux-mm@kvack.org.
 
 #
 # support for page migration