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: Honggang Li <enjoymindful@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

3 files changed, 8 insertions, 33 deletions

diff --git a/arch/um/include/shared/mem_user.h b/arch/um/include/shared/mem_user.h
index 46384acd547b..cb84414e3e66 100644
--- a/arch/um/include/shared/mem_user.h
+++ b/arch/um/include/shared/mem_user.h
@@ -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,
diff --git a/arch/um/kernel/physmem.c b/arch/um/kernel/physmem.c
index 30fdd5d0067b..549ecf3f5857 100644
--- a/arch/um/kernel/physmem.c
+++ b/arch/um/kernel/physmem.c
@@ -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;
-
-        phys_pages = physmem >> PAGE_SHIFT;
-        phys_len = phys_pages * sizeof(struct page);
-
-        iomem_pages = iomem >> PAGE_SHIFT;
-        iomem_len = iomem_pages * sizeof(struct page);
+        unsigned long phys_pages, highmem_pages;
+        unsigned long iomem_pages, total_pages;
 
+        phys_pages    = physmem >> PAGE_SHIFT;
+        iomem_pages   = iomem   >> PAGE_SHIFT;
         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);
-        }
+        total_pages   = phys_pages + iomem_pages + highmem_pages;
 
         max_mapnr = total_pages;
-        return 0;
 }
 
 void map_memory(unsigned long virt, unsigned long phys, unsigned long len,
diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c
index 016adf0985d5..9274eae6ae7b 100644
--- a/arch/um/kernel/um_arch.c
+++ b/arch/um/kernel/um_arch.c
@@ -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;