mm/mempolicy: remove or narrow the lock on current (78b132e9) · Commits · 戴 / test

It is not necessary to hold the lock of current when setting nodemask of a new policy. Signed-off-by:

mm/mempolicy.c

+1 −4

Original line number	Diff line number	Diff line
		@@ -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