Re: [PATCH] x86: Construct 32 bit boot time page tables in native format.

Mika Penttilä
2008-01-20T18:31:14Z

> + * This is how much memory *in addition to the memory covered up to
> + * and including _end* we need mapped initially. We need one bit for
> + * each possible page, but only in low memory, which means
> + * 2^32/4096/8 = 128K worst case (4G/4G split.)
> + *
> + * Modulo rounding, each megabyte assigned here requires a kilobyte of
> + * memory, which is currently unreclaimed.
> + *
> + * This should be a multiple of a page.
> + */
> +#define INIT_MAP_BEYOND_END (128*1024)
> +
> +/*
>

You have dropped the requirement to map all of low memory (the boot
allocator is used for instance to construct physical mem mapping).
Either you should fix your INIT_MAP_BEYOND_END or make a big comment
telling us why it isn't necessary anymore to map low mem.

--Mika