Re: [PATCH] udmabuf: vastly increase the size limit per dmabuf

See 
https://lore.kernel.org/dri-devel/[email protected]/ 
;)

On 03.08.26 16:41, Xaver Hugl wrote:
> Buffer sizes can get big very fast, and the previous limit of 64MB
> is easily hit nowadays.
> I hit this problem while working on better multi-gpu copies for KWin,
> where on my 5120x1440 monitor with scaling applied, some apps ended
> up using a resolution of 8192x2304, resulting in buffer sizes of
> roughly 75MB.
>
> As another reference, with merely 32 bits per pixel, buffers reach
> - 33MB for 4k
> - 133MB for 8k
> - 530MB for 16k
>
> With 64bpp, those sizes would be doubled, and even 4k would hit the
> previous 64MB limit.
>
> Signed-off-by: Xaver Hugl <[email protected]>
> Cc: [email protected]
> ---
>   drivers/dma-buf/udmabuf.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c
> index 2f94be1df525..8cbba7ddfa00 100644
> --- a/drivers/dma-buf/udmabuf.c
> +++ b/drivers/dma-buf/udmabuf.c
> @@ -20,9 +20,9 @@ static int list_limit = 1024;
>   module_param(list_limit, int, 0644);
>   MODULE_PARM_DESC(list_limit, "udmabuf_create_list->count limit. Default is 1024.");
>   
> -static int size_limit_mb = 64;
> +static int size_limit_mb = 1024;
>   module_param(size_limit_mb, int, 0644);
> -MODULE_PARM_DESC(size_limit_mb, "Max size of a dmabuf, in megabytes. Default is 64.");
> +MODULE_PARM_DESC(size_limit_mb, "Max size of a dmabuf, in megabytes. Default is 1024.");
>   
>   struct udmabuf {
>   	pgoff_t pagecount;

-- 
Robert Mader
Consultant Software Developer

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