Merge tag 'stable/frontswap.v16-tag' of git://git.kernel.org/pub/scm/linux/kernel...

[karo-tx-linux.git] / mm / Kconfig

diff --git a/mm/Kconfig b/mm/Kconfig
index e338407f1225f0873a8eb20761c86fd82db1dfc0..82fed4eb2b6fe39cfd0476afe46e9589e02b386f 100644 (file)
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -198,7 +198,7 @@ config COMPACTION
 config MIGRATION
        bool "Page migration"
        def_bool y
-       depends on NUMA || ARCH_ENABLE_MEMORY_HOTREMOVE || COMPACTION
+       depends on NUMA || ARCH_ENABLE_MEMORY_HOTREMOVE || COMPACTION || CMA
        help
          Allows the migration of the physical location of pages of processes
          while the virtual addresses are not changed. This is useful in
@@ -349,6 +349,16 @@ choice
          benefit.
 endchoice
 
+config CROSS_MEMORY_ATTACH
+       bool "Cross Memory Support"
+       depends on MMU
+       default y
+       help
+         Enabling this option adds the system calls process_vm_readv and
+         process_vm_writev which allow a process with the correct privileges
+         to directly read from or write to to another process's address space.
+         See the man page for more details.
+
 #
 # UP and nommu archs use km based percpu allocator
 #
@@ -379,3 +389,20 @@ 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.