diff mbox series

[v4,16/24] locking/lockdep, cpu/hotplus: Use a weaker annotation in AP thread

Message ID 1646377603-19730-17-git-send-email-byungchul.park@lge.com
State New
Headers show
Series DEPT(Dependency Tracker) | expand

Commit Message

Byungchul Park March 4, 2022, 7:06 a.m. UTC
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 <byungchul.park@lge.com>
---
 kernel/cpu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Sergei Shtylyov March 4, 2022, 7:28 p.m. UTC | #1
On 3/4/22 10:06 AM, Byungchul Park wrote:

> cb92173d1f0 (locking/lockdep, cpu/hotplug: Annotate AP thread) was

   You need to enclose the commit summary in (""), not just (). :-)

> 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 <byungchul.park@lge.com>
[...]

MBR, Sergey
Byungchul Park March 4, 2022, 11:36 p.m. UTC | #2
On Fri, Mar 04, 2022 at 10:28:57PM +0300, Sergei Shtylyov wrote:
> On 3/4/22 10:06 AM, Byungchul Park wrote:
> 
> > cb92173d1f0 (locking/lockdep, cpu/hotplug: Annotate AP thread) was
> 
>    You need to enclose the commit summary in (""), not just (). :-)

Thank you! I will!

> > 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 <byungchul.park@lge.com>
> [...]
> 
> MBR, Sergey
diff mbox series

Patch

diff --git a/kernel/cpu.c b/kernel/cpu.c
index 407a256..1f92a42 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -355,7 +355,7 @@  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)