Re: [PATCH] block: partition: optimize memory allocation in check_partition

[Joe Perches <joe@perches.com>]

On Fri, 2013-02-01 at 11:07 +0800, Ming Lei wrote:
> Currently, sizeof(struct parsed_partitions) may be 64KB in 32bit arch,
> so it is easy to trigger page allocation failure by check_partition,
[]
> This patch does below optimizations on the allocation of struct
> parsed_partitions to try to address the issue:
> 
> - make parsed_partitions.parts as pointer so that the pointed memory
> can fit in 32KB buffer, then approximate 32KB memory can be saved
> 
> - vmalloc the buffer pointed by parsed_partitions.parts because
> 32KB is still a bit big for kmalloc
[]
> diff --git a/block/partitions/check.h b/block/partitions/check.h
[]
> @@ -15,13 +15,15 @@ struct parsed_partitions {
>  		int flags;
>  		bool has_info;
>  		struct partition_meta_info info;
> -	} parts[DISK_MAX_PARTS];
> +	} *parts;

This is relatively unusual style.
Could you break out this struct instead?

struct partition_parts {
	...
};

and use

	struct partition_parts *parts;