Merge tag 'microblaze-3.12-rc1' of git://git.monstr.eu/linux-2.6-microblaze

[firefly-linux-kernel-4.4.55.git] / mm / Kconfig

diff --git a/mm/Kconfig b/mm/Kconfig
index 7e28ecfa8aa42663ba3153a984ee1dbe69f7e96b..6cdd27043303e7473925bbc04778a43481dc2205 100644 (file)
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -478,6 +478,60 @@ config FRONTSWAP
 
          If unsure, say Y to enable frontswap.
 
+config CMA
+       bool "Contiguous Memory Allocator"
+       depends on HAVE_MEMBLOCK
+       select MIGRATION
+       select MEMORY_ISOLATION
+       help
+         This enables the Contiguous Memory Allocator which allows other
+         subsystems to allocate big physically-contiguous blocks of memory.
+         CMA reserves a region of memory and allows only movable pages to
+         be allocated from it. This way, the kernel can use the memory for
+         pagecache and when a subsystem requests for contiguous area, the
+         allocated pages are migrated away to serve the contiguous request.
+
+         If unsure, say "n".
+
+config CMA_DEBUG
+       bool "CMA debug messages (DEVELOPMENT)"
+       depends on DEBUG_KERNEL && CMA
+       help
+         Turns on debug messages in CMA.  This produces KERN_DEBUG
+         messages for every CMA call as well as various messages while
+         processing calls such as dma_alloc_from_contiguous().
+         This option does not affect warning and error messages.
+
+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