powerpc/pseries: Fix buffer overflow when reading from pstore

[linux-imx.git] / mm / Kconfig

diff --git a/mm/Kconfig b/mm/Kconfig
index 7e28ecfa8aa42663ba3153a984ee1dbe69f7e96b..8028dcc6615c6bbd533adf060ea3d9db36b9a48c 100644 (file)
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -478,6 +478,36 @@ config FRONTSWAP
 
          If unsure, say Y to enable frontswap.
 
+config ZBUD
+       tristate
+       default n
+       help
+         A special purpose allocator for storing compressed pages.
+         It is designed to store up to two compressed pages per physical
+         page.  While this design limits storage density, it has simple and
+         deterministic reclaim properties that make it preferable to a higher
+         density approach when reclaim will be used.
+
+config ZSWAP
+       bool "Compressed cache for swap pages (EXPERIMENTAL)"
+       depends on FRONTSWAP && CRYPTO=y
+       select CRYPTO_LZO
+       select ZBUD
+       default n
+       help
+         A lightweight compressed cache for swap pages.  It takes
+         pages that are in the process of being swapped out and attempts to
+         compress them into a dynamically allocated RAM-based memory pool.
+         This can result in a significant I/O reduction on swap device and,
+         in the case where decompressing from RAM is faster that swap device
+         reads, can also improve workload performance.
+
+         This is marked experimental because it is a new feature (as of
+         v3.11) that interacts heavily with memory reclaim.  While these
+         interactions don't cause any known issues on simple memory setups,
+         they have not be fully explored on the large set of potential
+         configurations and workloads that exist.
+
 config MEM_SOFT_DIRTY
        bool "Track memory changes"
        depends on CHECKPOINT_RESTORE && HAVE_ARCH_SOFT_DIRTY