From f9fc166b790bd214083035d865653133b8a963d1 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Tue, 23 Feb 2021 01:10:09 +0100 Subject: rcu/nocb: Only cancel nocb timer if not polling This commit refrains deleting the ->nocb_timer if rcu_nocb is polling because it should not ever have been queued in the polling case. Signed-off-by: Frederic Weisbecker Cc: Josh Triplett Cc: Lai Jiangshan Cc: Joel Fernandes Cc: Neeraj Upadhyay Cc: Boqun Feng Signed-off-by: Paul E. McKenney --- kernel/rcu/tree_plugin.h | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) (limited to 'kernel/rcu') diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index 4253a0ecc14f..db28e3123f32 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -2176,18 +2176,18 @@ static void nocb_gp_wait(struct rcu_data *my_rdp) my_rdp->nocb_gp_gp = needwait_gp; my_rdp->nocb_gp_seq = needwait_gp ? wait_gp_seq : 0; if (bypass) { - raw_spin_lock_irqsave(&my_rdp->nocb_gp_lock, flags); - // Avoid race with first bypass CB. - if (my_rdp->nocb_defer_wakeup > RCU_NOCB_WAKE_NOT) { - WRITE_ONCE(my_rdp->nocb_defer_wakeup, RCU_NOCB_WAKE_NOT); - del_timer(&my_rdp->nocb_timer); - } if (!rcu_nocb_poll) { + raw_spin_lock_irqsave(&my_rdp->nocb_gp_lock, flags); + // Avoid race with first bypass CB. + if (my_rdp->nocb_defer_wakeup > RCU_NOCB_WAKE_NOT) { + WRITE_ONCE(my_rdp->nocb_defer_wakeup, RCU_NOCB_WAKE_NOT); + del_timer(&my_rdp->nocb_timer); + } // At least one child with non-empty ->nocb_bypass, so set // timer in order to avoid stranding its callbacks. mod_timer(&my_rdp->nocb_bypass_timer, j + 2); + raw_spin_unlock_irqrestore(&my_rdp->nocb_gp_lock, flags); } - raw_spin_unlock_irqrestore(&my_rdp->nocb_gp_lock, flags); } if (rcu_nocb_poll) { /* Polling, so trace if first poll in the series. */ -- cgit v1.2.3-70-g09d2