Make vunmap return the page array that was used at vmap. This is useful
if one has no structures to track the page array but simply stores the
virtual address somewhere. The disposition of the page array can be
decided upon after vunmap. vfree() may now also be used instead of
vunmap which will release the page array after vunmap'ping it.
As noted by Kamezawa: The same subsystem that provides the page array
to vmap must must use its own method to dispose of the page array.
If vfree() is called to free the page array then the page array must either
be
1. Allocated via the slab allocator
2. Allocated via vmalloc but then VM_VPAGES must have been passed at
vunmap to specify that a vfree is needed.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
---
include/linux/vmalloc.h | 2 +-
mm/vmalloc.c | 32 ++++++++++++++++++++++----------
2 files changed, 23 insertions(+), 11 deletions(-)
Index: linux-2.6.25-rc5-mm1/include/linux/vmalloc.h
===================================================================
--- linux-2.6.25-rc5-mm1.orig/include/linux/vmalloc.h 2008-03-18 12:20:12.295837331 -0700
+++ linux-2.6.25-rc5-mm1/include/linux/vmalloc.h 2008-03-19 18:17:42.093443900 -0700
@@ -50,7 +50,7 @@ extern void vfree(const void *addr);
extern void *vmap(struct page **pages, unsigned int count,
unsigned long flags, pgprot_t prot);
-extern void vunmap(const void *addr);
+extern struct page **vunmap(const void *addr);
extern int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
unsigned long pgoff);
Index: linux-2.6.25-rc5-mm1/mm/vmalloc.c
===================================================================
--- linux-2.6.25-rc5-mm1.orig/mm/vmalloc.c 2008-03-18 13:48:56.344025498 -0700
+++ linux-2.6.25-rc5-mm1/mm/vmalloc.c 2008-03-19 18:17:42.125444187 -0700
@@ -153,6 +153,7 @@ int map_vm_area(struct vm_struct *area,
unsigned long addr = (unsigned long) area->addr;
unsigned long end = addr + area->size - PAGE_SIZE;
int ...
