Commit 6b6482bb authored by Oleg Nesterov's avatar Oleg Nesterov Committed by Linus Torvalds

mempolicy: remove the "task" arg of vma_policy_mof() and simplify it

1. vma_policy_mof(task) is simply not safe unless task == current,
   it can race with do_exit()->mpol_put(). Remove this arg and update
   its single caller.

2. vma can not be NULL, remove this check and simplify the code.
Signed-off-by: default avatarOleg Nesterov <oleg@redhat.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 8d90274b
...@@ -136,7 +136,7 @@ struct mempolicy *mpol_shared_policy_lookup(struct shared_policy *sp, ...@@ -136,7 +136,7 @@ struct mempolicy *mpol_shared_policy_lookup(struct shared_policy *sp,
struct mempolicy *get_vma_policy(struct task_struct *tsk, struct mempolicy *get_vma_policy(struct task_struct *tsk,
struct vm_area_struct *vma, unsigned long addr); struct vm_area_struct *vma, unsigned long addr);
bool vma_policy_mof(struct task_struct *task, struct vm_area_struct *vma); bool vma_policy_mof(struct vm_area_struct *vma);
extern void numa_default_policy(void); extern void numa_default_policy(void);
extern void numa_policy_init(void); extern void numa_policy_init(void);
......
...@@ -1946,7 +1946,7 @@ void task_numa_work(struct callback_head *work) ...@@ -1946,7 +1946,7 @@ void task_numa_work(struct callback_head *work)
vma = mm->mmap; vma = mm->mmap;
} }
for (; vma; vma = vma->vm_next) { for (; vma; vma = vma->vm_next) {
if (!vma_migratable(vma) || !vma_policy_mof(p, vma)) if (!vma_migratable(vma) || !vma_policy_mof(vma))
continue; continue;
/* /*
......
...@@ -1646,27 +1646,24 @@ struct mempolicy *get_vma_policy(struct task_struct *task, ...@@ -1646,27 +1646,24 @@ struct mempolicy *get_vma_policy(struct task_struct *task,
return pol; return pol;
} }
bool vma_policy_mof(struct task_struct *task, struct vm_area_struct *vma) bool vma_policy_mof(struct vm_area_struct *vma)
{ {
struct mempolicy *pol = NULL; struct mempolicy *pol;
if (vma) {
if (vma->vm_ops && vma->vm_ops->get_policy) {
bool ret = false;
pol = vma->vm_ops->get_policy(vma, vma->vm_start); if (vma->vm_ops && vma->vm_ops->get_policy) {
if (pol && (pol->flags & MPOL_F_MOF)) bool ret = false;
ret = true;
mpol_cond_put(pol);
return ret; pol = vma->vm_ops->get_policy(vma, vma->vm_start);
} if (pol && (pol->flags & MPOL_F_MOF))
ret = true;
mpol_cond_put(pol);
pol = vma->vm_policy; return ret;
} }
pol = vma->vm_policy;
if (!pol) if (!pol)
pol = get_task_policy(task); pol = get_task_policy(current);
return pol->flags & MPOL_F_MOF; return pol->flags & MPOL_F_MOF;
} }
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment