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Commit 9e6a57d2 authored by Honggang Li's avatar Honggang Li Committed by Richard Weinberger
Browse files

um: delete unnecessary bootmem struct page array 



1) uml kernel bootmem managed through bootmem_data->node_bootmem_map,
not the struct page array, so the array is unnecessary.

2) the bootmem struct page array has been pointed by a *local* pointer,
struct page *map, in init_maps function. The array can be accessed only
in init_maps's scope. As a result, uml kernel wastes about 1% of total
memory.

Signed-off-by: default avatarHonggang Li <enjoymindful@gmail.com>
Signed-off-by: default avatarRichard Weinberger <richard@nod.at>
parent 67131230

arch/um/include/shared/mem_user.h

+1 −1
Original line number Diff line number Diff line
@@ -49,7 +49,7 @@ extern int iomem_size; 
extern int init_mem_user(void);

extern void setup_memory(void *entry);

extern unsigned long find_iomem(char *driver, unsigned long *len_out);

extern int init_maps(unsigned long physmem, unsigned long iomem,

extern void mem_total_pages(unsigned long physmem, unsigned long iomem,

		     unsigned long highmem);

extern unsigned long get_vm(unsigned long len);

extern void setup_physmem(unsigned long start, unsigned long usable,

arch/um/kernel/physmem.c

+6 −26
Original line number Diff line number Diff line
@@ -22,39 +22,19 @@ EXPORT_SYMBOL(high_physmem); 


extern unsigned long long physmem_size;



int __init init_maps(unsigned long physmem, unsigned long iomem,

void __init mem_total_pages(unsigned long physmem, unsigned long iomem,

		     unsigned long highmem)

{

	struct page *p, *map;

	unsigned long phys_len, phys_pages, highmem_len, highmem_pages;

	unsigned long iomem_len, iomem_pages, total_len, total_pages;

	int i;

	unsigned long phys_pages, highmem_pages;

	unsigned long iomem_pages, total_pages;



	phys_pages    = physmem >> PAGE_SHIFT;

	phys_len = phys_pages * sizeof(struct page);



	iomem_pages   = iomem   >> PAGE_SHIFT;

	iomem_len = iomem_pages * sizeof(struct page);



	highmem_pages = highmem >> PAGE_SHIFT;

	highmem_len = highmem_pages * sizeof(struct page);



	total_pages   = phys_pages + iomem_pages + highmem_pages;

	total_len = phys_len + iomem_len + highmem_len;



	map = alloc_bootmem_low_pages(total_len);

	if (map == NULL)

		return -ENOMEM;



	for (i = 0; i < total_pages; i++) {

		p = &map[i];

		memset(p, 0, sizeof(struct page));

		SetPageReserved(p);

		INIT_LIST_HEAD(&p->lru);

	}



	max_mapnr = total_pages;

	return 0;

}



void map_memory(unsigned long virt, unsigned long phys, unsigned long len,

arch/um/kernel/um_arch.c

+1 −6
Original line number Diff line number Diff line
@@ -348,12 +348,7 @@ int __init linux_main(int argc, char **argv) 
	start_vm = VMALLOC_START;



	setup_physmem(uml_physmem, uml_reserved, physmem_size, highmem);

	if (init_maps(physmem_size, iomem_size, highmem)) {

		printf("Failed to allocate mem_map for %Lu bytes of physical "

		       "memory and %Lu bytes of highmem\n", physmem_size,

		       highmem);

		exit(1);

	}

	mem_total_pages(physmem_size, iomem_size, highmem);



	virtmem_size = physmem_size;

	stack = (unsigned long) argv;