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authorFrederic Weisbecker2022-11-25 14:54:59 +0100
committerGreg Kroah-Hartman2023-03-10 09:32:51 +0100
commit24f259ce3a7c8951f80c874c6193a8f8de139c22 (patch)
tree773cbfaba670970a5ed94ade64a812eac9813635 /kernel/rcu
parenta2b0cda452b78d96c28d0ee984f1d0ede23b1948 (diff)
rcu-tasks: Remove preemption disablement around srcu_read_[un]lock() calls
[ Upstream commit 44757092958bdd749775022f915b7ac974384c2a ] Ever since the following commit: 5a41344a3d83 ("srcu: Simplify __srcu_read_unlock() via this_cpu_dec()") SRCU doesn't rely anymore on preemption to be disabled in order to modify the per-CPU counter. And even then it used to be done from the API itself. Therefore and after checking further, it appears to be safe to remove the preemption disablement around __srcu_read_[un]lock() in exit_tasks_rcu_start() and exit_tasks_rcu_finish() Suggested-by: Boqun Feng <boqun.feng@gmail.com> Suggested-by: Paul E. McKenney <paulmck@kernel.org> Suggested-by: Neeraj Upadhyay <quic_neeraju@quicinc.com> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Stable-dep-of: 28319d6dc5e2 ("rcu-tasks: Fix synchronize_rcu_tasks() VS zap_pid_ns_processes()") Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'kernel/rcu')
-rw-r--r--kernel/rcu/tasks.h4
1 files changed, 0 insertions, 4 deletions
diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h
index 688c461036f5..80e75e7926cc 100644
--- a/kernel/rcu/tasks.h
+++ b/kernel/rcu/tasks.h
@@ -1008,9 +1008,7 @@ EXPORT_SYMBOL_GPL(show_rcu_tasks_classic_gp_kthread);
*/
void exit_tasks_rcu_start(void) __acquires(&tasks_rcu_exit_srcu)
{
- preempt_disable();
current->rcu_tasks_idx = __srcu_read_lock(&tasks_rcu_exit_srcu);
- preempt_enable();
}
/*
@@ -1022,9 +1020,7 @@ void exit_tasks_rcu_finish(void) __releases(&tasks_rcu_exit_srcu)
{
struct task_struct *t = current;
- preempt_disable();
__srcu_read_unlock(&tasks_rcu_exit_srcu, t->rcu_tasks_idx);
- preempt_enable();
exit_tasks_rcu_finish_trace(t);
}