RE: [PATCH 6/8] drivers: add Contiguous Memory Allocator

From: Marek Szyprowski
Date: Tue Jul 05 2011 - 06:25:46 EST


Hello,

On Tuesday, July 05, 2011 9:42 AM Marek Szyprowski wrote:

> 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 CMA_MIGRATE_TYPE and
> gives back to the system. Kernel is allowed to allocate 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@xxxxxxxxxxx>
> Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
> CC: Michal Nazarewicz <mina86@xxxxxxxxxx>
> ---
> drivers/base/Kconfig | 77 +++++++++
> drivers/base/Makefile | 1 +
> drivers/base/dma-contiguous.c | 367
> ++++++++++++++++++++++++++++++++++++++++
> include/linux/dma-contiguous.h | 104 +++++++++++
> 4 files changed, 549 insertions(+), 0 deletions(-)
> create mode 100644 drivers/base/dma-contiguous.c
> create mode 100644 include/linux/dma-contiguous.h
>
> diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig
> index d57e8d0..95ae1a7 100644
> --- a/drivers/base/Kconfig
> +++ b/drivers/base/Kconfig
> @@ -168,4 +168,81 @@ config SYS_HYPERVISOR
> bool
> default n
>
> +config CMA
> + bool "Contiguous Memory Allocator"
> + depends HAVE_DMA_CONTIGUOUS && HAVE_MEMBLOCK

The above line should be obviously "depends on HAVE_DMA_CONTIGUOUS &&
HAVE_MEMBLOCK".
I'm sorry for posting broken version.

(snipped)

Best regards
--
Marek Szyprowski
Samsung Poland R&D Center



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