diff options
| author | pengdonglin <pengdonglin@xiaomi.com> | 2025-09-16 12:47:30 +0800 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2025-09-16 08:36:24 -1000 |
| commit | 58ab6d25a1bfca42510979cb2b6921f1c807bd02 (patch) | |
| tree | 5472ee698a06923a78ca629ec4d9f8d7187af9cd | |
| parent | 3ee4211ef8693377f67624a46b4f8577f6a495d9 (diff) | |
cgroup/cpuset: Remove redundant rcu_read_lock/unlock() in spin_lock
Since commit a8bb74acd8efe ("rcu: Consolidate RCU-sched update-side function definitions")
there is no difference between rcu_read_lock(), rcu_read_lock_bh() and
rcu_read_lock_sched() in terms of RCU read section and the relevant grace
period. That means that spin_lock(), which implies rcu_read_lock_sched(),
also implies rcu_read_lock().
There is no need no explicitly start a RCU read section if one has already
been started implicitly by spin_lock().
Simplify the code and remove the inner rcu_read_lock() invocation.
Cc: Waiman Long <longman@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Waiman Long <longman@redhat.com>
Signed-off-by: pengdonglin <pengdonglin@xiaomi.com>
Signed-off-by: pengdonglin <dolinux.peng@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
| -rw-r--r-- | kernel/cgroup/cpuset.c | 6 |
1 files changed, 0 insertions, 6 deletions
diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index 0d41b4993f8c..caa885823eeb 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -4107,7 +4107,6 @@ void cpuset_cpus_allowed(struct task_struct *tsk, struct cpumask *pmask) struct cpuset *cs; spin_lock_irqsave(&callback_lock, flags); - rcu_read_lock(); cs = task_cs(tsk); if (cs != &top_cpuset) @@ -4129,7 +4128,6 @@ void cpuset_cpus_allowed(struct task_struct *tsk, struct cpumask *pmask) cpumask_copy(pmask, possible_mask); } - rcu_read_unlock(); spin_unlock_irqrestore(&callback_lock, flags); } @@ -4202,9 +4200,7 @@ nodemask_t cpuset_mems_allowed(struct task_struct *tsk) unsigned long flags; spin_lock_irqsave(&callback_lock, flags); - rcu_read_lock(); guarantee_online_mems(task_cs(tsk), &mask); - rcu_read_unlock(); spin_unlock_irqrestore(&callback_lock, flags); return mask; @@ -4299,10 +4295,8 @@ bool cpuset_current_node_allowed(int node, gfp_t gfp_mask) /* Not hardwall and node outside mems_allowed: scan up cpusets */ spin_lock_irqsave(&callback_lock, flags); - rcu_read_lock(); cs = nearest_hardwall_ancestor(task_cs(current)); allowed = node_isset(node, cs->mems_allowed); - rcu_read_unlock(); spin_unlock_irqrestore(&callback_lock, flags); return allowed; |