[PATCH v7 1/3] dma-contiguous: provide the ability to reserve per-numa CMA

[Randy Dunlap]

On 8/21/20 4:33 AM, Barry Song wrote:
> ---
>  -v7: with respect to Will's comments
>  * move to use for_each_online_node
>  * add description if users don't specify pernuma_cma
>  * provide default value for CONFIG_DMA_PERNUMA_CMA
> 
>  .../admin-guide/kernel-parameters.txt         |  11 ++
>  include/linux/dma-contiguous.h                |   6 ++
>  kernel/dma/Kconfig                            |  11 ++
>  kernel/dma/contiguous.c                       | 100 ++++++++++++++++--
>  4 files changed, 118 insertions(+), 10 deletions(-)
> 
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index bdc1f33fd3d1..c609527fc35a 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -599,6 +599,17 @@
>  			altogether. For more information, see
>  			include/linux/dma-contiguous.h
>  
> +	pernuma_cma=nn[MG]
> +			[ARM64,KNL]
> +			Sets the size of kernel per-numa memory area for
> +			contiguous memory allocations. A value of 0 disables
> +			per-numa CMA altogether. And If this option is not
> +			specificed, the default value is 0.
> +			With per-numa CMA enabled, DMA users on node nid will
> +			first try to allocate buffer from the pernuma area
> +			which is located in node nid, if the allocation fails,
> +			they will fallback to the global default memory area.
> +

Entries in kernel-parameters.txt are supposed to be in alphabetical order
but this one is not.  If you want to keep it near the cma= entry, you can
rename it like Mike suggested.  Otherwise it needs to be moved.


>  	cmo_free_hint=	[PPC] Format: { yes | no }
>  			Specify whether pages are marked as being inactive
>  			when they are freed.  This is used in CMO environments



-- 
~Randy