2 files changed, 18 insertions, 0 deletions

diff --git a/mm/Kconfig b/mm/Kconfig
index e338407f1225..2613c910935a 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -379,3 +379,20 @@ config CLEANCACHE
           in a negligible performance hit.
 
           If unsure, say Y to enable cleancache
+
+config FRONTSWAP
+        bool "Enable frontswap to cache swap pages if tmem is present"
+        depends on SWAP
+        default n
+        help
+          Frontswap is so named because it can be thought of as the opposite
+          of a "backing" store for a swap device.  The data is stored into
+          "transcendent memory", memory that is not directly accessible or
+          addressable by the kernel and is of unknown and possibly
+          time-varying size.  When space in transcendent memory is available,
+          a significant swap I/O reduction may be achieved.  When none is
+          available, all frontswap calls are reduced to a single pointer-
+          compare-against-NULL resulting in a negligible performance hit
+          and swap data is stored as normal on the matching swap device.
+
+          If unsure, say Y to enable frontswap.
diff --git a/mm/Makefile b/mm/Makefile
index 50ec00ef2a0e..306742a28266 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -26,6 +26,7 @@ obj-$(CONFIG_HAVE_MEMBLOCK) += memblock.o
 
 obj-$(CONFIG_BOUNCE)    += bounce.o
 obj-$(CONFIG_SWAP)      += page_io.o swap_state.o swapfile.o thrash.o
+obj-$(CONFIG_FRONTSWAP) += frontswap.o
 obj-$(CONFIG_HAS_DMA)   += dmapool.o
 obj-$(CONFIG_HUGETLBFS) += hugetlb.o
 obj-$(CONFIG_NUMA)      += mempolicy.o