2012/2/23 Marek Szyprowski m.szyprowski@samsung.com:
The Contiguous Memory Allocator is a set of helper functions for DMA mapping framework that improves allocations of contiguous memory chunks.
CMA grabs memory on system boot, marks it with MIGRATE_CMA migrate type and gives back to the system. Kernel is allowed to allocate only movable pages within CMA's managed memory so that it can be used for example for page cache when DMA mapping do not use it. On dma_alloc_from_contiguous() request such pages are migrated out of CMA area to free required contiguous block and fulfill the request. This allows to allocate large contiguous chunks of memory at any time assuming that there is enough free memory available in the system.
This code is heavily based on earlier works by Michal Nazarewicz.
Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com Signed-off-by: Kyungmin Park kyungmin.park@samsung.com Signed-off-by: Michal Nazarewicz mina86@mina86.com Acked-by: Arnd Bergmann arnd@arndb.de Tested-by: Rob Clark rob.clark@linaro.org Tested-by: Ohad Ben-Cohen ohad@wizery.com Tested-by: Benjamin Gaignard benjamin.gaignard@linaro.org Tested-by: Robert Nelson robertcnelson@gmail.com
if there is a /proc/cmainfo like /proc/slabinfo, it might be helpful to people as we can see the usage of CMA clearly.
Thanks barry