From 78b132e9bae922f1e8bd9d137f0c27b81c44f15d Mon Sep 17 00:00:00 2001 From: Wei Yang Date: Tue, 13 Oct 2020 16:57:08 -0700 Subject: mm/mempolicy: remove or narrow the lock on current It is not necessary to hold the lock of current when setting nodemask of a new policy. Signed-off-by: Wei Yang Signed-off-by: Andrew Morton Reviewed-by: Andrew Morton Link: https://lkml.kernel.org/r/20200921040416.86185-1-richard.weiyang@linux.alibaba.com Signed-off-by: Linus Torvalds --- mm/mempolicy.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) diff --git a/mm/mempolicy.c b/mm/mempolicy.c index eddbe4e56c73..69ce708c3a3a 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -875,13 +875,12 @@ static long do_set_mempolicy(unsigned short mode, unsigned short flags, goto out; } - task_lock(current); ret = mpol_set_nodemask(new, nodes, scratch); if (ret) { - task_unlock(current); mpol_put(new); goto out; } + task_lock(current); old = current->mempolicy; current->mempolicy = new; if (new && new->mode == MPOL_INTERLEAVE) @@ -1324,9 +1323,7 @@ static long do_mbind(unsigned long start, unsigned long len, NODEMASK_SCRATCH(scratch); if (scratch) { mmap_write_lock(mm); - task_lock(current); err = mpol_set_nodemask(new, nmask, scratch); - task_unlock(current); if (err) mmap_write_unlock(mm); } else -- cgit v1.2.3