Re: [patch] reduce stack usage of sanitize_e820_map

[Denis Vlasenko]

On 15 August 2002 19:48, Benjamin LaHaise wrote:
> Hello,
>
> Currently, sanitize_e820_map uses 0x738 bytes of stack.  The patch below
> moves the arrays into __initdata, reducing stack usage to 0x34 bytes.

Is that a real problem? sanitize_e820_map will be called just once at init
time...

> +struct change_member change_point_list[2*E820MAX] __initdata;
> +struct change_member *change_point[2*E820MAX] __initdata;
> +struct e820entry *overlap_list[E820MAX] __initdata;
> +struct e820entry new_bios[E820MAX] __initdata;

Does this enlarge on-disk kernel image?
Shouldn't they be static?

>  static int __init sanitize_e820_map(struct e820entry * biosmap, char *
> pnr_map) {
> -	struct change_member {
> -		struct e820entry *pbios; /* pointer to original bios entry */
> -		unsigned long long addr; /* address for this change point */
> -	};
> -	struct change_member change_point_list[2*E820MAX];
> -	struct change_member *change_point[2*E820MAX];
> -	struct e820entry *overlap_list[E820MAX];
> -	struct e820entry new_bios[E820MAX];
>  	struct change_member *change_tmp;
>  	unsigned long current_type, last_type;
>  	unsigned long long last_addr;

--
vda