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From:   Chengming Zhou <zhouchengming@bytedance.com>
To:     hannes@cmpxchg.org, tj@kernel.org, mkoutny@suse.com,
        surenb@google.com
Cc:     mingo@redhat.com, peterz@infradead.org, gregkh@linuxfoundation.org,
        corbet@lwn.net, cgroups@vger.kernel.org, linux-doc@vger.kernel.org,
        linux-kernel@vger.kernel.org, songmuchun@bytedance.com,
        Chengming Zhou <zhouchengming@bytedance.com>
Subject: [PATCH v4 02/10] sched/psi: don't create cgroup PSI files when psi_disabled
Date:   Fri, 26 Aug 2022 00:41:03 +0800
Message-Id: <20220825164111.29534-3-zhouchengming@bytedance.com>
In-Reply-To: <20220825164111.29534-1-zhouchengming@bytedance.com>
References: <20220825164111.29534-1-zhouchengming@bytedance.com>
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commit 3958e2d0c34e ("cgroup: make per-cgroup pressure stall tracking configurable")
make PSI can be configured to skip per-cgroup stall accounting. And
doesn't expose PSI files in cgroup hierarchy.

This patch do the same thing when psi_disabled.

Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
---
 kernel/cgroup/cgroup.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index 03dbbf8a8c28..2f79ddf9a85d 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -3748,6 +3748,9 @@ static void cgroup_pressure_release(struct kernfs_open_file *of)
 
 bool cgroup_psi_enabled(void)
 {
+	if (static_branch_likely(&psi_disabled))
+		return false;
+
 	return (cgroup_feature_disable_mask & (1 << OPT_FEATURE_PRESSURE)) == 0;
 }
 
-- 
2.37.2