[PATCH v2 8/8] mm, vmalloc: remove list management of vmlist after initializing vmalloc

From: Joonsoo Kim
Date: Wed Mar 13 2013 - 02:34:36 EST


From: Joonsoo Kim <js1304@xxxxxxxxx>

Now, there is no need to maintain vmlist after initializing vmalloc.
So remove related code and data structure.

Signed-off-by: Joonsoo Kim <js1304@xxxxxxxxx>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 7e63984..151da8a 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -273,10 +273,6 @@ static unsigned long cached_align;

static unsigned long vmap_area_pcpu_hole;

-/*** Old vmalloc interfaces ***/
-static DEFINE_RWLOCK(vmlist_lock);
-static struct vm_struct *vmlist;
-
static struct vmap_area *__find_vmap_area(unsigned long addr)
{
struct rb_node *n = vmap_area_root.rb_node;
@@ -318,7 +314,7 @@ static void __insert_vmap_area(struct vmap_area *va)
rb_link_node(&va->rb_node, parent, p);
rb_insert_color(&va->rb_node, &vmap_area_root);

- /* address-sort this list so it is usable like the vmlist */
+ /* address-sort this list */
tmp = rb_prev(&va->rb_node);
if (tmp) {
struct vmap_area *prev;
@@ -1130,6 +1126,7 @@ void *vm_map_ram(struct page **pages, unsigned int count, int node, pgprot_t pro
}
EXPORT_SYMBOL(vm_map_ram);

+static struct vm_struct *vmlist __initdata;
/**
* vm_area_add_early - add vmap area early during boot
* @vm: vm_struct to add
@@ -1301,10 +1298,8 @@ static void setup_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va,
spin_unlock(&vmap_area_lock);
}

-static void insert_vmalloc_vmlist(struct vm_struct *vm)
+static void clear_vm_unlist(struct vm_struct *vm)
{
- struct vm_struct *tmp, **p;
-
/*
* Before removing VM_UNLIST,
* we should make sure that vm has proper values.
@@ -1312,22 +1307,13 @@ static void insert_vmalloc_vmlist(struct vm_struct *vm)
*/
smp_wmb();
vm->flags &= ~VM_UNLIST;
-
- write_lock(&vmlist_lock);
- for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) {
- if (tmp->addr >= vm->addr)
- break;
- }
- vm->next = *p;
- *p = vm;
- write_unlock(&vmlist_lock);
}

static void insert_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va,
unsigned long flags, const void *caller)
{
setup_vmalloc_vm(vm, va, flags, caller);
- insert_vmalloc_vmlist(vm);
+ clear_vm_unlist(vm);
}

static struct vm_struct *__get_vm_area_node(unsigned long size,
@@ -1370,10 +1356,9 @@ static struct vm_struct *__get_vm_area_node(unsigned long size,

/*
* When this function is called from __vmalloc_node_range,
- * we do not add vm_struct to vmlist here to avoid
- * accessing uninitialized members of vm_struct such as
- * pages and nr_pages fields. They will be set later.
- * To distinguish it from others, we use a VM_UNLIST flag.
+ * we add VM_UNLIST flag to avoid accessing uninitialized
+ * members of vm_struct such as pages and nr_pages fields.
+ * They will be set later.
*/
if (flags & VM_UNLIST)
setup_vmalloc_vm(area, va, flags, caller);
@@ -1462,20 +1447,6 @@ struct vm_struct *remove_vm_area(const void *addr)
va->flags &= ~VM_VM_AREA;
spin_unlock(&vmap_area_lock);

- if (!(vm->flags & VM_UNLIST)) {
- struct vm_struct *tmp, **p;
- /*
- * remove from list and disallow access to
- * this vm_struct before unmap. (address range
- * confliction is maintained by vmap.)
- */
- write_lock(&vmlist_lock);
- for (p = &vmlist; (tmp = *p) != vm; p = &tmp->next)
- ;
- *p = tmp->next;
- write_unlock(&vmlist_lock);
- }
-
vmap_debug_free_range(va->va_start, va->va_end);
free_unmap_vmap_area(va);
vm->size -= PAGE_SIZE;
@@ -1695,10 +1666,11 @@ void *__vmalloc_node_range(unsigned long size, unsigned long align,
return NULL;

/*
- * In this function, newly allocated vm_struct is not added
- * to vmlist at __get_vm_area_node(). so, it is added here.
+ * In this function, newly allocated vm_struct has VM_UNLIST flag.
+ * It means that vm_struct is not fully initialized.
+ * Now, it is fully initialized, so remove this flag here.
*/
- insert_vmalloc_vmlist(area);
+ clear_vm_unlist(area);

/*
* A ref_count = 3 is needed because the vm_struct and vmap_area
@@ -2594,7 +2566,7 @@ static void show_numa_info(struct seq_file *m, struct vm_struct *v)
if (!counters)
return;

- /* Pair with smp_wmb() in insert_vmalloc_vmlist() */
+ /* Pair with smp_wmb() in clear_vm_unlist() */
smp_rmb();
if (v->flags & VM_UNLIST)
return;
--
1.7.9.5

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