>From 29e5e83f8f3988ea1396d61b4d5764e7904f82c5 Mon Sep 17 00:00:00 2001 From: Honggang Li Date: Mon, 16 Jun 2014 18:05:47 +0800 Subject: [PATCH] UML 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. 3) commit 5678d7fc97ac75f7401ce77897773cc0bb3afee5 obsoleted the init_maps function. Signed-off-by: Honggang Li --- arch/um/include/shared/mem_user.h | 2 +- arch/um/kernel/physmem.c | 32 ++++++-------------------------- arch/um/kernel/um_arch.c | 7 +------ 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 46384ac..cb84414 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 30fdd5d..549ecf3 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 6043c76..dbd5bda 100644 --- a/arch/um/kernel/um_arch.c +++ b/arch/um/kernel/um_arch.c @@ -338,12 +338,7 @@ 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; -- 1.8.3.1