From: Zhang Yanfei <[email protected]>
VM_UNLIST was used to indicate that the vm_struct is not listed
in vmlist. But after commit 4341fa4:
mm, vmalloc: remove list management of vmlist after initializing vmalloc
, the meaning of this flag changed. It now means the vm_struct
is not fully initialized. So renaming it to VM_UNINITIALIZED
seems more reasonable.
Also change clear_vm_unlist to clear_vm_uninitialized_flag.
Signed-off-by: Zhang Yanfei <[email protected]>
---
include/linux/vmalloc.h | 12 ++++++------
mm/vmalloc.c | 18 +++++++++---------
2 files changed, 15 insertions(+), 15 deletions(-)
diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
index dd0a2c8..4b8a891 100644
--- a/include/linux/vmalloc.h
+++ b/include/linux/vmalloc.h
@@ -10,12 +10,12 @@
struct vm_area_struct; /* vma defining user mapping in mm_types.h */
/* bits in flags of vmalloc's vm_struct below */
-#define VM_IOREMAP 0x00000001 /* ioremap() and friends */
-#define VM_ALLOC 0x00000002 /* vmalloc() */
-#define VM_MAP 0x00000004 /* vmap()ed pages */
-#define VM_USERMAP 0x00000008 /* suitable for remap_vmalloc_range */
-#define VM_VPAGES 0x00000010 /* buffer for pages was vmalloc'ed */
-#define VM_UNLIST 0x00000020 /* vm_struct is not listed in vmlist */
+#define VM_IOREMAP 0x00000001 /* ioremap() and friends */
+#define VM_ALLOC 0x00000002 /* vmalloc() */
+#define VM_MAP 0x00000004 /* vmap()ed pages */
+#define VM_USERMAP 0x00000008 /* suitable for remap_vmalloc_range */
+#define VM_VPAGES 0x00000010 /* buffer for pages was vmalloc'ed */
+#define VM_UNINITIALIZED 0x00000020 /* vm_struct is not fully initialized */
/* bits [20..32] reserved for arch specific ioremap internals */
/*
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 9a0d711..fe41a4f 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -1311,15 +1311,15 @@ static void setup_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va,
spin_unlock(&vmap_area_lock);
}
-static void clear_vm_unlist(struct vm_struct *vm)
+static void clear_vm_uninitialized_flag(struct vm_struct *vm)
{
/*
- * Before removing VM_UNLIST,
+ * Before removing VM_UNINITIALIZED,
* we should make sure that vm has proper values.
* Pair with smp_rmb() in show_numa_info().
*/
smp_wmb();
- vm->flags &= ~VM_UNLIST;
+ vm->flags &= ~VM_UNINITIALIZED;
}
static struct vm_struct *__get_vm_area_node(unsigned long size,
@@ -1657,7 +1657,7 @@ void *__vmalloc_node_range(unsigned long size, unsigned long align,
if (!size || (size >> PAGE_SHIFT) > totalram_pages)
goto fail;
- area = __get_vm_area_node(size, align, VM_ALLOC | VM_UNLIST,
+ area = __get_vm_area_node(size, align, VM_ALLOC | VM_UNINITIALIZED,
start, end, node, gfp_mask, caller);
if (!area)
goto fail;
@@ -1667,11 +1667,11 @@ void *__vmalloc_node_range(unsigned long size, unsigned long align,
goto fail;
/*
- * In this function, newly allocated vm_struct has VM_UNLIST flag.
- * It means that vm_struct is not fully initialized.
+ * In this function, newly allocated vm_struct has VM_UNINITIALIZED
+ * flag. It means that vm_struct is not fully initialized.
* Now, it is fully initialized, so remove this flag here.
*/
- clear_vm_unlist(area);
+ clear_vm_uninitialized_flag(area);
/*
* A ref_count = 3 is needed because the vm_struct and vmap_area
@@ -2591,9 +2591,9 @@ static void show_numa_info(struct seq_file *m, struct vm_struct *v)
if (!counters)
return;
- /* Pair with smp_wmb() in clear_vm_unlist() */
+ /* Pair with smp_wmb() in clear_vm_uninitialized_flag() */
smp_rmb();
- if (v->flags & VM_UNLIST)
+ if (v->flags & VM_UNINITIALIZED)
return;
memset(counters, 0, nr_node_ids * sizeof(unsigned int));
--
1.7.1
From: Zhang Yanfei <[email protected]>
We should check the VM_UNITIALIZED flag in s_show(). If this
flag is set, that said, the vm_struct is not fully initialized.
So it is unnecessary to try to show the information contained
in vm_struct.
We checked this flag in show_numa_info(), but I think it's better
to check it earlier.
Signed-off-by: Zhang Yanfei <[email protected]>
---
mm/vmalloc.c | 10 +++++-----
1 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index fe41a4f..722268b 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -2591,11 +2591,6 @@ static void show_numa_info(struct seq_file *m, struct vm_struct *v)
if (!counters)
return;
- /* Pair with smp_wmb() in clear_vm_uninitialized_flag() */
- smp_rmb();
- if (v->flags & VM_UNINITIALIZED)
- return;
-
memset(counters, 0, nr_node_ids * sizeof(unsigned int));
for (nr = 0; nr < v->nr_pages; nr++)
@@ -2624,6 +2619,11 @@ static int s_show(struct seq_file *m, void *p)
v = va->vm;
+ /* Pair with smp_wmb() in clear_vm_uninitialized_flag() */
+ smp_rmb();
+ if (v->flags & VM_UNINITIALIZED)
+ return 0;
+
seq_printf(m, "0x%pK-0x%pK %7ld",
v->addr, v->addr + v->size, v->size);
--
1.7.1