This patch assumes that there is no valid usage of
vmalloced_or_vmaped_page->lru.
In such a case vm_struct->array could be eliminated.
It saves some memory and simplifies code a bit.
In vmap/vunmap case vm_struct->page_list is used only
in map_vm_area(), so it is ok to do:
addr1 = vmap(pages, count);
addr2 = vmap(pages, count);
...
vunmap(addr1);
vunmap(addr2);
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/include/linux/vmalloc.h | 8 +--
25-akpm/mm/vmalloc.c | 82 +++++++++++++++-------------------------
2 files changed, 35 insertions(+), 55 deletions(-)
diff -puN include/linux/vmalloc.h~vmalloc-use-list-of-pages-instead-of-array-in-vm_struct include/linux/vmalloc.h
--- 25/include/linux/vmalloc.h~vmalloc-use-list-of-pages-instead-of-array-in-vm_struct 2005-03-06 22:20:08.000000000 -0800
+++ 25-akpm/include/linux/vmalloc.h 2005-03-06 22:20:08.000000000 -0800
@@ -2,6 +2,7 @@
#define _LINUX_VMALLOC_H
#include <linux/spinlock.h>
+#include <linux/list.h>
#include <asm/page.h> /* pgprot_t */
/* bits in vm_struct->flags */
@@ -14,8 +15,7 @@ struct vm_struct {
void *addr;
unsigned long size;
unsigned long flags;
- struct page **pages;
- unsigned int nr_pages;
+ struct list_head page_list;
unsigned long phys_addr;
struct vm_struct *next;
};
@@ -30,6 +30,7 @@ extern void *__vmalloc(unsigned long siz
extern void *__vmalloc_area(struct vm_struct *area, int gfp_mask, pgprot_t prot);
extern void vfree(void *addr);
+struct page;
extern void *vmap(struct page **pages, unsigned int count,
unsigned long flags, pgprot_t prot);
extern void vunmap(void *addr);
@@ -41,8 +42,7 @@ extern struct vm_struct *get_vm_area(uns
extern struct vm_struct *__get_vm_area(unsigned long size, unsigned long flags,
unsigned long start, unsigned long end);
extern struct vm_struct *remove_vm_area(void *addr);
-extern int map_vm_area(struct vm_struct *area, pgprot_t prot,
- struct page ***pages);
+extern int map_vm_area(struct vm_struct *area, pgprot_t prot);
extern void unmap_vm_area(struct vm_struct *area);
/*
diff -puN mm/vmalloc.c~vmalloc-use-list-of-pages-instead-of-array-in-vm_struct mm/vmalloc.c
--- 25/mm/vmalloc.c~vmalloc-use-list-of-pages-instead-of-array-in-vm_struct 2005-03-06 22:20:08.000000000 -0800
+++ 25-akpm/mm/vmalloc.c 2005-03-06 22:32:22.000000000 -0800
@@ -115,7 +115,7 @@ static void unmap_area_pud(pgd_t *pgd, u
static int map_area_pte(pte_t *pte, unsigned long address,
unsigned long size, pgprot_t prot,
- struct page ***pages)
+ struct list_head **pages)
{
unsigned long base, end;
@@ -126,22 +126,23 @@ static int map_area_pte(pte_t *pte, unsi
end = PMD_SIZE;
do {
- struct page *page = **pages;
+ struct page *page;
+
WARN_ON(!pte_none(*pte));
- if (!page)
- return -ENOMEM;
+
+ *pages = (*pages)->next;
+ page = list_entry(*pages, struct page, lru);
set_pte_at(&init_mm, base + address, pte, mk_pte(page, prot));
address += PAGE_SIZE;
pte++;
- (*pages)++;
} while (address < end);
return 0;
}
static int map_area_pmd(pmd_t *pmd, unsigned long address,
unsigned long size, pgprot_t prot,
- struct page ***pages)
+ struct list_head **pages)
{
unsigned long base, end;
@@ -166,7 +167,7 @@ static int map_area_pmd(pmd_t *pmd, unsi
static int map_area_pud(pud_t *pud, unsigned long address,
unsigned long end, pgprot_t prot,
- struct page ***pages)
+ struct list_head **pages)
{
do {
pmd_t *pmd = pmd_alloc(&init_mm, pud, address);
@@ -202,8 +203,9 @@ void unmap_vm_area(struct vm_struct *are
flush_tlb_kernel_range((unsigned long) area->addr, end);
}
-int map_vm_area(struct vm_struct *area, pgprot_t prot, struct page ***pages)
+int map_vm_area(struct vm_struct *area, pgprot_t prot)
{
+ struct list_head *pages = &area->page_list;
unsigned long address = (unsigned long) area->addr;
unsigned long end = address + (area->size-PAGE_SIZE);
unsigned long next;
@@ -222,7 +224,7 @@ int map_vm_area(struct vm_struct *area,
next = (address + PGDIR_SIZE) & PGDIR_MASK;
if (next < address || next > end)
next = end;
- if (map_area_pud(pud, address, next, prot, pages)) {
+ if (map_area_pud(pud, address, next, prot, &pages)) {
err = -ENOMEM;
break;
}
@@ -294,8 +296,7 @@ found:
area->flags = flags;
area->addr = (void *)addr;
area->size = size;
- area->pages = NULL;
- area->nr_pages = 0;
+ INIT_LIST_HEAD(&area->page_list);
area->phys_addr = 0;
write_unlock(&vmlist_lock);
@@ -372,20 +373,12 @@ void __vunmap(void *addr, int deallocate
WARN_ON(1);
return;
}
-
- if (deallocate_pages) {
- int i;
- for (i = 0; i < area->nr_pages; i++) {
- if (unlikely(!area->pages[i]))
- BUG();
- __free_page(area->pages[i]);
- }
+ if (deallocate_pages) {
+ struct page *page, *tmp;
- if (area->nr_pages > PAGE_SIZE/sizeof(struct page *))
- vfree(area->pages);
- else
- kfree(area->pages);
+ list_for_each_entry_safe(page, tmp, &area->page_list, lru)
+ __free_page(page);
}
kfree(area);
@@ -444,13 +437,17 @@ void *vmap(struct page **pages, unsigned
{
struct vm_struct *area;
- if (count > num_physpages)
- return NULL;
-
area = get_vm_area((count << PAGE_SHIFT), flags);
if (!area)
return NULL;
- if (map_vm_area(area, prot, &pages)) {
+
+ while (count--) {
+ struct page *page = *pages++;
+ BUG_ON(!page);
+ list_add_tail(&page->lru, &area->page_list);
+ }
+
+ if (map_vm_area(area, prot)) {
vunmap(area->addr);
return NULL;
}
@@ -462,37 +459,20 @@ EXPORT_SYMBOL(vmap);
void *__vmalloc_area(struct vm_struct *area, int gfp_mask, pgprot_t prot)
{
- struct page **pages;
- unsigned int nr_pages, array_size, i;
+ unsigned int nr_pages;
nr_pages = (area->size - PAGE_SIZE) >> PAGE_SHIFT;
- array_size = (nr_pages * sizeof(struct page *));
- area->nr_pages = nr_pages;
- /* Please note that the recursion is strictly bounded. */
- if (array_size > PAGE_SIZE)
- pages = __vmalloc(array_size, gfp_mask, PAGE_KERNEL);
- else
- pages = kmalloc(array_size, (gfp_mask & ~__GFP_HIGHMEM));
- area->pages = pages;
- if (!area->pages) {
- remove_vm_area(area->addr);
- kfree(area);
- return NULL;
- }
- memset(area->pages, 0, array_size);
-
- for (i = 0; i < area->nr_pages; i++) {
- area->pages[i] = alloc_page(gfp_mask);
- if (unlikely(!area->pages[i])) {
- /* Successfully allocated i pages, free them in __vunmap() */
- area->nr_pages = i;
+ while (nr_pages--) {
+ struct page *page = alloc_page(gfp_mask);
+ if (!page)
goto fail;
- }
+ list_add_tail(&page->lru, &area->page_list);
}
- if (map_vm_area(area, prot, &pages))
+ if (map_vm_area(area, prot))
goto fail;
+
return area->addr;
fail:
_