[Linaro-mm-sig] [PATCH 2/3] ARM: DMA-Mapping: print warning when atomic coherent allocation fails

[Hiroshi Doyu]

On Mon, 20 Aug 2012 12:47:27 +0200
Marek Szyprowski <m.szyprowski at samsung.com> wrote:

> Print a loud warning when system runs out of memory from atomic coherent
> pool to let users notice the potential problem.
> 
> Reported-by: Aaro Koskinen <aaro.koskinen at iki.fi>
> Signed-off-by: Marek Szyprowski <m.szyprowski at samsung.com>
> ---
>  arch/arm/mm/dma-mapping.c |    3 +++
>  1 files changed, 3 insertions(+), 0 deletions(-)
> 
> diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
> index d1cc9c1..25963ea 100644
> --- a/arch/arm/mm/dma-mapping.c
> +++ b/arch/arm/mm/dma-mapping.c
> @@ -461,6 +461,9 @@ static void *__alloc_from_pool(size_t size, struct page **ret_page)
>  		bitmap_set(pool->bitmap, pageno, count);
>  		ptr = pool->vaddr + PAGE_SIZE * pageno;
>  		*ret_page = pool->page + pageno;
> +	} else {
> +		pr_err("Atomic coherent pool too small!\n"
> +		       "Please increase it with  kernel parameter!\n");

It might be a little bit nicer if the current pool size is printed in
the above too. That could be the hint for how much to specify in
"coherent_pool=".