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| author |   Oleg Nesterov <oleg@redhat.com> | 2014-10-09 15:27:55 -0700 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2014-10-09 22:25:56 -0400 |
| commit | 2c7c3a7d08b28278112f2aaa0b7cf53140101e2a (patch) | |
| tree | 44e7df021c66b03557afb3a79e1324fa50fbc729 /mm | |
| parent | mempolicy: fix show_numa_map() vs exec() + do_set_mempolicy() race (diff) | |
| download | linux-dev-2c7c3a7d08b28278112f2aaa0b7cf53140101e2a.tar.xz linux-dev-2c7c3a7d08b28278112f2aaa0b7cf53140101e2a.zip | |
mempolicy: kill do_set_mempolicy()->down_write(&mm->mmap_sem)
Remove down_write(&mm->mmap_sem) in do_set_mempolicy(). This logic
was never correct and it is no longer needed, see the previous patch.
Signed-off-by: Oleg 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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/mempolicy.c | 15 |
1 files changed, 1 insertions, 14 deletions
diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 4378c334e89b..9695a9a3ab90 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -802,7 +802,6 @@ static long do_set_mempolicy(unsigned short mode, unsigned short flags, nodemask_t *nodes) { struct mempolicy *new, *old; - struct mm_struct *mm = current->mm; NODEMASK_SCRATCH(scratch); int ret; @@ -814,20 +813,11 @@ static long do_set_mempolicy(unsigned short mode, unsigned short flags, ret = PTR_ERR(new); goto out; } - /* - * prevent changing our mempolicy while show_numa_maps() - * is using it. - * Note: do_set_mempolicy() can be called at init time - * with no 'mm'. - */ - if (mm) - down_write(&mm->mmap_sem); + task_lock(current); ret = mpol_set_nodemask(new, nodes, scratch); if (ret) { task_unlock(current); - if (mm) - up_write(&mm->mmap_sem); mpol_put(new); goto out; } @@ -837,9 +827,6 @@ static long do_set_mempolicy(unsigned short mode, unsigned short flags, nodes_weight(new->v.nodes)) current->il_next = first_node(new->v.nodes); task_unlock(current); - if (mm) - up_write(&mm->mmap_sem); - mpol_put(old); ret = 0; out: |