[PATCH -mm 2/2] mm, vmalloc: Check VM_UNINITIALIZED flag in s_show instead of show_numa_info

Zhang Yanfei
2013-06-08T08:45:08Z

From: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>

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 <zhangyanfei@cn.fujitsu.com>
---
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