For RCU tasks trace, the userspace execution is also a valid quiescent state, if the task is in userspace, the ->trc_reader_nesting should be zero and if the ->trc_reader_special.b.need_qs is not set, set the tasks ->trc_reader_special.b.need_qs is TRC_NEED_QS_CHECKED, this cause grace-period kthread remove it from holdout list if it remains here. This commit add rcu_tasks_trace_qs() to rcu_flavor_sched_clock_irq() when the kernel built with no PREEMPT_RCU. Signed-off-by: Zqiang <qiang1.zhang@xxxxxxxxx> --- v1->v2: Fix build error due to undeclared rcu_tasks_trace_qs(), note in no-PREEMPT_RCU kernel, the RCU Tasks is replaced by RCU, so rcu_note_voluntary_context_switch() only include rcu_tasks_trace_qs(). kernel/rcu/tree_plugin.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index 4152816dd29f..5fb0b2dd24fd 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -976,7 +976,7 @@ static void rcu_flavor_sched_clock_irq(int user) * neither access nor modify, at least not while the * corresponding CPU is online. */ - + rcu_note_voluntary_context_switch(current); rcu_qs(); } } -- 2.25.1
