[PATCH] vmalloc: optimization, cleanup, bugfixes

- reorder 'struct vm_struct' to speedup lookups on CPUS with small cache
  lines.  The fields 'next,addr,size' should be now in the same cache line,
  to speedup lookups.

- One minor cleanup in __get_vm_area_node()

- Bugfixes in vmalloc_user() and vmalloc_32_user() NULL returns from
  __vmalloc() and __find_vm_area() were not tested.

[[email protected]: remove redundant BUG_ONs]
Signed-off-by: Eric Dumazet <[email protected]>
Cc: Nick Piggin <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
This commit is contained in:
Eric Dumazet authored and Linus Torvalds committed 2006-11-13 07:40:42 -08:00
1 parent 088406bcf6
commit 2b4ac44e7c
2 files changed
+15 -14

No files matched your search

+2 -1
View File
@@ -23,13 +23,14 @@ struct vm_area_struct;
#endif
struct vm_struct {
/* keep next,addr,size together to speedup lookups */
struct vm_struct *next;
void *addr;
unsigned long size;
unsigned long flags;
struct page **pages;
unsigned int nr_pages;
unsigned long phys_addr;
struct vm_struct *next;
};
/*
+13 -13
View File
@@ -186,10 +186,8 @@ static struct vm_struct *__get_vm_area_node(unsigned long size, unsigned long fl
if (unlikely(!area))
return NULL;
if (unlikely(!size)) {
kfree (area);
if (unlikely(!size))
return NULL;
}
/*
* We always allocate a guard page.
@@ -532,11 +530,12 @@ void *vmalloc_user(unsigned long size)
void *ret;
ret = __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO, PAGE_KERNEL);
write_lock(&vmlist_lock);
area = __find_vm_area(ret);
area->flags |= VM_USERMAP;
write_unlock(&vmlist_lock);
if (ret) {
write_lock(&vmlist_lock);
area = __find_vm_area(ret);
area->flags |= VM_USERMAP;
write_unlock(&vmlist_lock);
}
return ret;
}
EXPORT_SYMBOL(vmalloc_user);
@@ -605,11 +604,12 @@ void *vmalloc_32_user(unsigned long size)
void *ret;
ret = __vmalloc(size, GFP_KERNEL | __GFP_ZERO, PAGE_KERNEL);
write_lock(&vmlist_lock);
area = __find_vm_area(ret);
area->flags |= VM_USERMAP;
write_unlock(&vmlist_lock);
if (ret) {
write_lock(&vmlist_lock);
area = __find_vm_area(ret);
area->flags |= VM_USERMAP;
write_unlock(&vmlist_lock);
}
return ret;
}
EXPORT_SYMBOL(vmalloc_32_user);