mm,vmacache: add debug data
Introduce a CONFIG_DEBUG_VM_VMACACHE option to enable counting the cache
hit rate -- exported in /proc/vmstat.
Any updates to the caching scheme needs this kind of data, thus it can
save some work re-implementing the counting all the time.
Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Cc: Aswin Chandramouleeswaran <aswin@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 99c8bfe..c2de650 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -501,6 +501,16 @@
If unsure, say N.
+config DEBUG_VM_VMACACHE
+ bool "Debug VMA caching"
+ depends on DEBUG_VM
+ help
+ Enable this to turn on VMA caching debug information. Doing so
+ can cause significant overhead, so only enable it in non-production
+ environments.
+
+ If unsure, say N.
+
config DEBUG_VM_RB
bool "Debug VM red-black trees"
depends on DEBUG_VM