[PATCH] mm/Kconfig: give DISCONTIG more help text

This gives DISCONTIGMEM a bit more help text to explain what it does, not just
when to choose it.

Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/mm/Kconfig b/mm/Kconfig
index 7d3a0054cba1e6edff86da313fd49fc2c4adcb62..8283685f3bb3098c5a04120936f836ebb3342a4b 100644 (file)
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -23,6 +23,16 @@ config DISCONTIGMEM_MANUAL
        bool "Discontigious Memory"
        depends on ARCH_DISCONTIGMEM_ENABLE
        help
+         This option provides enhanced support for discontiguous
+         memory systems, over FLATMEM.  These systems have holes
+         in their physical address spaces, and this option provides
+         more efficient handling of these holes.  However, the vast
+         majority of hardware has quite flat address spaces, and
+         can have degraded performance from extra overhead that
+         this option imposes.
+
+         Many NUMA configurations will have this as the only option.
+
          If unsure, choose "Flat Memory" over this option.
 
 endchoice