[PATCH] sched/core: Fix wrong burst unit in cgroup2 cpu.max write

From: Kailun Qin
Date: Fri Sep 10 2021 - 04:23:22 EST


In cpu_max_write(), as the eventual tg_set_cfs_bandwidth() operates on
the burst in nsec which is input from tg_get_cfs_burst() in usec, it
should be converted into nsec accordingly.

If not, this may cause a write into cgroup2 cpu.max to unexpectedly
change an already set cpu.max.burst.

This patch addresses the above issue.

Signed-off-by: Kailun Qin <kailun.qin@xxxxxxxxx>
---
kernel/sched/core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index c4462c454ab9..fc9fcc56149f 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -10711,7 +10711,7 @@ static ssize_t cpu_max_write(struct kernfs_open_file *of,
{
struct task_group *tg = css_tg(of_css(of));
u64 period = tg_get_cfs_period(tg);
- u64 burst = tg_get_cfs_burst(tg);
+ u64 burst = (u64)tg_get_cfs_burst(tg) * NSEC_PER_USEC;
u64 quota;
int ret;

--
2.25.1