lkml.org 
[lkml]   [2020]   [Nov]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 17/19] cpu/hotplug: Add lockdep_is_cpus_held()
Date
RCU needs to check if the cpu hotplug lock is held, in the middle of
other conditions to check the sanity of RCU-nocb. Provide a helper for
that.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Neeraj Upadhyay <neeraju@codeaurora.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Boqun Feng <boqun.feng@gmail.com>
---
include/linux/cpu.h | 1 +
kernel/cpu.c | 7 +++++++
2 files changed, 8 insertions(+)

diff --git a/include/linux/cpu.h b/include/linux/cpu.h
index d6428aaf67e7..27eb3875e45a 100644
--- a/include/linux/cpu.h
+++ b/include/linux/cpu.h
@@ -118,6 +118,7 @@ extern void cpus_read_lock(void);
extern void cpus_read_unlock(void);
extern int cpus_read_trylock(void);
extern void lockdep_assert_cpus_held(void);
+extern int lockdep_is_cpus_held(void);
extern void cpu_hotplug_disable(void);
extern void cpu_hotplug_enable(void);
void clear_tasks_mm_cpumask(int cpu);
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 6ff2578ecf17..3cca5b27de25 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -330,6 +330,13 @@ void lockdep_assert_cpus_held(void)
percpu_rwsem_assert_held(&cpu_hotplug_lock);
}

+#ifdef CONFIG_LOCKDEP
+int lockdep_is_cpus_held(void)
+{
+ return percpu_rwsem_is_held(&cpu_hotplug_lock);
+}
+#endif
+
static void lockdep_acquire_cpus_lock(void)
{
rwsem_acquire(&cpu_hotplug_lock.dep_map, 0, 0, _THIS_IP_);
--
2.25.1
\
 
 \ /
  Last update: 2020-11-13 13:14    [W:1.420 / U:0.220 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site