Messages in this thread Patch in this message | | | Date | Thu, 21 Aug 2014 21:01:38 +0200 | From | Oleg Nesterov <> | Subject | [PATCH 3/4] mempolicy: kill do_set_mempolicy()->down_write(&mm->mmap_sem) |
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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> --- mm/mempolicy.c | 15 +-------------- 1 files changed, 1 insertions(+), 14 deletions(-)
diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 4378c33..9695a9a 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: -- 1.5.5.1
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