Re: [PATCH] mm: allocate section_map for sparse_init

From: Mel Gorman
Date: Thu Mar 13 2008 - 07:19:49 EST


On (12/03/08 10:51), Yinghai Lu didst pronounce:
> [PATCH] mm: allocate section_map for sparse_init
>
> allocate section_map in bootmem instead of using __initdata.
>
> need to apply it after
> [PATCH] mm: fix boundary checking in free_bootmem_core
> [PATCH] mm: make mem_map allocation continuous.
>
>
> Signed-off-by: Yinghai Lu <yhlu.kernel@xxxxxxxxx>

> Index: linux-2.6/mm/sparse.c
> ===================================================================
> --- linux-2.6.orig/mm/sparse.c
> +++ linux-2.6/mm/sparse.c
> @@ -285,8 +285,6 @@ struct page __init *sparse_early_mem_map
> return NULL;
> }
>
> -/* section_map pointer array is 64k */
> -static __initdata struct page *section_map[NR_MEM_SECTIONS];
> /*
> * Allocate the accumulated non-linear sections, allocate a mem_map
> * for each and record the physical to section mapping.
> @@ -296,6 +294,9 @@ void __init sparse_init(void)
> unsigned long pnum;
> struct page *map;
> unsigned long *usemap;
> + struct page **section_map;
> + int size;
> + int node;
>
> /*
> * map is using big page (aka 2M in x86 64 bit)
> @@ -305,13 +306,17 @@ void __init sparse_init(void)
> * then in big system, the memmory will have a lot hole...
> * here try to allocate 2M pages continously.
> */
> + size = sizeof(struct page *) * NR_MEM_SECTIONS;
> + section_map = alloc_bootmem(size);
> + if (!section_map)
> + panic("can not allocate section_map\n");
> +
> for (pnum = 0; pnum < NR_MEM_SECTIONS; pnum++) {
> if (!present_section_nr(pnum))
> continue;
> section_map[pnum] = sparse_early_mem_map_alloc(pnum);
> }
>
> -
> for (pnum = 0; pnum < NR_MEM_SECTIONS; pnum++) {
> if (!present_section_nr(pnum))
> continue;
> @@ -327,6 +332,9 @@ void __init sparse_init(void)
> sparse_init_one_section(__nr_to_section(pnum), pnum, map,
> usemap);
> }
> +
> + for_each_online_node(node)
> + free_bootmem_node(NODE_DATA(node), __pa(section_map), size);

Why are you iterating every online node here instead of just calling
free_bootmem(__pa(section_map), size) ?

> }
>
> #ifdef CONFIG_MEMORY_HOTPLUG


--
Mel Gorman
Part-time Phd Student Linux Technology Center
University of Limerick IBM Dublin Software Lab
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/