Because SRCU-fast does not use IPIs for its grace periods, there is no need for real-time workloads to switch to an IPI-free mode, and there is in turn no need for either rcu_task_trace_heavyweight_enter() or rcu_task_trace_heavyweight_exit(). This commit therefore removes them.
Signed-off-by: Paul E. McKenney <[email protected]> Cc: Frederic Weisbecker <[email protected]> Cc: Andrii Nakryiko <[email protected]> Cc: Alexei Starovoitov <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: <[email protected]> --- kernel/context_tracking.c | 20 -------------------- 1 file changed, 20 deletions(-) diff --git a/kernel/context_tracking.c b/kernel/context_tracking.c index fb5be6e9b423..a743e7ffa6c0 100644 --- a/kernel/context_tracking.c +++ b/kernel/context_tracking.c @@ -54,24 +54,6 @@ static __always_inline void rcu_task_enter(void) #endif /* #if defined(CONFIG_TASKS_RCU) && defined(CONFIG_NO_HZ_FULL) */ } -/* Turn on heavyweight RCU tasks trace readers on kernel exit. */ -static __always_inline void rcu_task_trace_heavyweight_enter(void) -{ -#ifdef CONFIG_TASKS_TRACE_RCU - if (IS_ENABLED(CONFIG_TASKS_TRACE_RCU_READ_MB)) - current->trc_reader_special.b.need_mb = true; -#endif /* #ifdef CONFIG_TASKS_TRACE_RCU */ -} - -/* Turn off heavyweight RCU tasks trace readers on kernel entry. */ -static __always_inline void rcu_task_trace_heavyweight_exit(void) -{ -#ifdef CONFIG_TASKS_TRACE_RCU - if (IS_ENABLED(CONFIG_TASKS_TRACE_RCU_READ_MB)) - current->trc_reader_special.b.need_mb = false; -#endif /* #ifdef CONFIG_TASKS_TRACE_RCU */ -} - /* * Record entry into an extended quiescent state. This is only to be * called when not already in an extended quiescent state, that is, @@ -85,7 +67,6 @@ static noinstr void ct_kernel_exit_state(int offset) * critical sections, and we also must force ordering with the * next idle sojourn. */ - rcu_task_trace_heavyweight_enter(); // Before CT state update! // RCU is still watching. Better not be in extended quiescent state! WARN_ON_ONCE(IS_ENABLED(CONFIG_RCU_EQS_DEBUG) && !rcu_is_watching_curr_cpu()); (void)ct_state_inc(offset); @@ -108,7 +89,6 @@ static noinstr void ct_kernel_enter_state(int offset) */ seq = ct_state_inc(offset); // RCU is now watching. Better not be in an extended quiescent state! - rcu_task_trace_heavyweight_exit(); // After CT state update! WARN_ON_ONCE(IS_ENABLED(CONFIG_RCU_EQS_DEBUG) && !(seq & CT_RCU_WATCHING)); } -- 2.40.1
