[PATCH] cgroup: remove redundant assignment in while loop of cgroup_calc_subtree_ss_mask()

From: Peng Wang
Date: Mon Jul 22 2019 - 07:41:51 EST


new_ss_mask is always not less than cur_ss_mask.
We don not need to update it with cur_ss_mask's value.

Signed-off-by: Peng Wang <rocking@xxxxxxxxxx>
---
kernel/cgroup/cgroup.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index 300b0c416341..2b8c39dabd26 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -1520,7 +1520,7 @@ static umode_t cgroup_file_mode(const struct cftype *cft)
*/
static u16 cgroup_calc_subtree_ss_mask(u16 subtree_control, u16 this_ss_mask)
{
- u16 cur_ss_mask = subtree_control;
+ u16 cur_ss_mask = subtree_control, new_ss_mask;
struct cgroup_subsys *ss;
int ssid;

@@ -1528,9 +1528,8 @@ static u16 cgroup_calc_subtree_ss_mask(u16 subtree_control, u16 this_ss_mask)

cur_ss_mask |= cgrp_dfl_implicit_ss_mask;

+ new_ss_mask = cur_ss_mask;
while (true) {
- u16 new_ss_mask = cur_ss_mask;
-
do_each_subsys_mask(ss, ssid, cur_ss_mask) {
new_ss_mask |= ss->depends_on;
} while_each_subsys_mask();
--
2.19.1