linux-kernel - [PATCH -next] sched: Dec __cfs_bandwith_used in destroy_cfs

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:   Tue, 6 Jul 2021 16:38:20 +0800
From:   Zhang Qiao <zhangqiao22@...wei.com>
To:     <mingo@...hat.com>, <peterz@...radead.org>,
        <juri.lelli@...hat.com>, <vincent.guittot@...aro.org>
CC:     <pjt@...gle.com>, <linux-kernel@...r.kernel.org>
Subject: [PATCH -next] sched: Dec __cfs_bandwith_used in destroy_cfs_bandwidth()

__cfs_bandwith_uesd is a static_key to control cfs bandwidth
feature. When adding a cfs_bandwidth group, we need increase
the key, and decrease it when removing. But currently when we
remove a cfs_bandwidth group, we don't decrease the key and
this switch will always be on even if there is no cfs bandwidth
group in the system.
Therefore, when removing a cfs bandwidth group, we decrease
__cfs_bandwith_used by calling cfs_bandwidth_usage_dec().

Fixes: 56f570e512ee ("sched: use jump labels to reduce overhead when bandwidth control is inactive")
Signed-off-by: Zhang Qiao <zhangqiao22@...wei.com>
---
 kernel/sched/fair.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 103e31e53e2b..857e8908b7f7 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -5344,6 +5344,9 @@ static void destroy_cfs_bandwidth(struct cfs_bandwidth *cfs_b)
 	if (!cfs_b->throttled_cfs_rq.next)
 		return;

+	if (cfs_b->quota != RUNTIME_INF)
+		cfs_bandwidth_usage_dec();
+
 	hrtimer_cancel(&cfs_b->period_timer);
 	hrtimer_cancel(&cfs_b->slack_timer);
 }
-- 
2.18.0.huawei.25