From:   Byungchul Park <max.byungchul.park@gmail.com>
To:     linux-kernel@vger.kernel.org
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Subject: [PATCH v9 15/25] locking/lockdep, cpu/hotplus: Use a weaker annotation in AP thread
Date:   Tue, 31 Jan 2023 17:39:44 +0900
Message-Id: <1675154394-25598-16-git-send-email-max.byungchul.park@gmail.com>
In-Reply-To: <1675154394-25598-1-git-send-email-max.byungchul.park@gmail.com>
References: <1675154394-25598-1-git-send-email-max.byungchul.park@gmail.com>
Precedence: bulk

cb92173d1f0 ("locking/lockdep, cpu/hotplug: Annotate AP thread") was
introduced to make lockdep_assert_cpus_held() work in AP thread.

However, the annotation is too strong for that purpose. We don't have to
use more than try lock annotation for that.

Furthermore, now that Dept was introduced, false positive alarms was
reported by that. Replaced it with try lock annotation.

Signed-off-by: Byungchul Park <max.byungchul.park@gmail.com>
---
 kernel/cpu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/cpu.c b/kernel/cpu.c
index 6c0a92c..6a9b9c3 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -356,7 +356,7 @@ int lockdep_is_cpus_held(void)
 
 static void lockdep_acquire_cpus_lock(void)
 {
-	rwsem_acquire(&cpu_hotplug_lock.dep_map, 0, 0, _THIS_IP_);
+	rwsem_acquire(&cpu_hotplug_lock.dep_map, 0, 1, _THIS_IP_);
 }
 
 static void lockdep_release_cpus_lock(void)
-- 
1.9.1