From 844ccdd7dce2c1a6ea9b437fcf8c3265b136e4a5 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Tue, 3 Oct 2017 16:51:47 -0700 Subject: rcu: Eliminate rcu_irq_enter_disabled() Now that the irq path uses the rcu_nmi_{enter,exit}() algorithm, rcu_irq_enter() and rcu_irq_exit() may be used from any context. There is thus no need for rcu_irq_enter_disabled() and for the checks using it. This commit therefore eliminates rcu_irq_enter_disabled(). Signed-off-by: Paul E. McKenney --- kernel/rcu/tree.c | 22 ++-------------------- 1 file changed, 2 insertions(+), 20 deletions(-) (limited to 'kernel/rcu') diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index d123474fe829..444aa2b3f24d 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -270,20 +270,6 @@ static DEFINE_PER_CPU(struct rcu_dynticks, rcu_dynticks) = { .dynticks = ATOMIC_INIT(RCU_DYNTICK_CTRL_CTR), }; -/* - * There's a few places, currently just in the tracing infrastructure, - * that uses rcu_irq_enter() to make sure RCU is watching. But there's - * a small location where that will not even work. In those cases - * rcu_irq_enter_disabled() needs to be checked to make sure rcu_irq_enter() - * can be called. - */ -static DEFINE_PER_CPU(bool, disable_rcu_irq_enter); - -bool rcu_irq_enter_disabled(void) -{ - return this_cpu_read(disable_rcu_irq_enter); -} - /* * Record entry into an extended quiescent state. This is only to be * called when not already in an extended quiescent state. @@ -792,10 +778,8 @@ static void rcu_eqs_enter_common(bool user) do_nocb_deferred_wakeup(rdp); } rcu_prepare_for_idle(); - __this_cpu_inc(disable_rcu_irq_enter); - rdtp->dynticks_nesting = 0; /* Breaks tracing momentarily. */ - rcu_dynticks_eqs_enter(); /* After this, tracing works again. */ - __this_cpu_dec(disable_rcu_irq_enter); + rdtp->dynticks_nesting = 0; + rcu_dynticks_eqs_enter(); rcu_dynticks_task_enter(); /* @@ -1001,10 +985,8 @@ static void rcu_eqs_exit(bool user) if (oldval) { rdtp->dynticks_nesting++; } else { - __this_cpu_inc(disable_rcu_irq_enter); rcu_eqs_exit_common(1, user); rdtp->dynticks_nesting = 1; - __this_cpu_dec(disable_rcu_irq_enter); WRITE_ONCE(rdtp->dynticks_nmi_nesting, DYNTICK_IRQ_NONIDLE); } } -- cgit v1.2.3-59-g8ed1b